discovery of 4-amino-8-quinoline carboxamides as novel

Discovery of 4‑Amino-8-quinoline Carboxamides as Novel,Submicromolar Inhibitors of NAD-Hydrolyzing Enzyme CD38J. David Becherer, Eric E. Boros, Tiffany Y. Carpenter, David J. Cowan, David N. Deaton,*Curt D. Haffner, Michael R. Jeune, Istvan W. Kaldor, J. Chuck Poole, Frank Preugschat, Tara R. Rheault,Christie A. Schulte, Barry G. Shearer, Todd W. Shearer, Lisa M. Shewchuk, Terrence L. Smalley, Jr.,Eugene L. Stewart, J. Darren Stuart, and John C. Ulrich

GlaxoSmithKline Research and Development, 5 Moore Drive, P.O. Box 13398, Research Triangle Park, North Carolina 27709,United States

ABSTRACT: Starting from the micromolar 8-quinolinecarboxamide high-throughput screening hit 1a, a systematic ex-ploration of the structure−activity relationships (SAR) of the4-, 6-, and 8-substituents of the quinoline ring resulted in theidentification of approximately 10−100-fold more potent humanCD38 inhibitors. Several of these molecules also exhibitedpharmacokinetic parameters suitable for in vivo animal studies,including low clearances and decent oral bioavailability. Twoof these CD38 inhibitors, 1ah and 1ai, were shown to elevateNAD tissue levels in liver and muscle in a diet-induced obese (DIO) C57BL/6 mouse model. These inhibitor tool compoundswill enable further biological studies of the CD38 enzyme as well as the investigation of the therapeutic implications of NADenhancement in disease models of abnormally low NAD.

■ INTRODUCTION

In the ongoing study of immune cells, numerous laboratorieshave generated monoclonal antibodies (mAbs) against epitopeson the cell surface of leukocytes as a means to immunophe-notype these white blood cells. In an effort to classify andharmonize the many recognition motifs, the InternationalWorkshop and Conference on Human Leukocyte Differ-entiation Antigens (HLDA) developed a nomenclature system,designating cell surface molecules that are recognized by twospecific mAbs as numbered clusters of differentiation (CD)(e.g., CD4, CD8, CD26). These CD proteins can have multipleand diverse functions including recognizing antigens, signalingas receptors, adhering to cell surfaces, and acting as enzymes.One such CD protein, CD38, was originally identified as

T10 by a murine mAb obtained from ascitic fluid of CAF1 miceinjected with human thymocytes.1 Subsequently, the proteinwas localized to chromosome 42 and cloned.3 CD38 is a type IImembrane protein, containing a single N-terminal trans-membrane domain with multiple asparagine-linked glycosyla-tion sites at its extracellular C-terminal end. In addition to itsexpression in immune cells, including T cells, B cells, anddendritic cells, CD38 is also expressed in multiple tissues,including bone, brain, intestine, kidney, liver, muscle, pancreas,and prostate.4 CD38 serves as a receptor for the immunoglo-bulin CD31 (PECAM-1), and this interaction is implicated inleukocyte migration.5

In addition to its receptor functions, CD38 can also act as anenzyme (EC 3.2.2.5). It catalyzes the transformation of theredox cofactor nicotinamide adenine dinucleotide (NAD) intothe second messenger signaling molecule cyclic ADP-ribose

(cADPR), which has been implicated in the regulation ofcytosolic calcium fluxes, and cADPR’s hydrolysis to ADP-ribose.6,7

Furthermore, CD38 can function as a NAD glycohydrolase(NADase), reducing the pool size of this important enzymecofactor, affecting its many dependent proteins, including thesirtuins, the poly(ADP-ribose) polymerases (PARPs), andoxidoreductases.NAD levels are decreased in the aged as well as the obese;

however, exercise or caloric restriction can result in NAD eleva-tion.8,9 One potential approach to increasing NAD levels isto inhibit NAD-consuming enzymes like CD38. Support forthis supposition is demonstrated in CD38(−/−) mice, whichexhibit elevated NAD levels relative to those in wild-typemice.10 Moreover, these knockout mice have increased energyexpenditure and are resistant to weight gain when fed a high-fatdiet. Thus, a small molecule inhibitor of the enzyme functionof CD38 that could increase NAD levels under conditionsof abnormally low NAD, like obesity, might have therapeuticutility.Although there are a few articles disclosing CD38 inhibitors

in the literature, most of these molecules exhibit only modestpotency.11−17 Desiring more potent inhibitors, with drug prop-erties suitable for oral dosing, a program was begun to discovernovel classes of CD38 inhibitors suitable for probing NADbiology. A high-throughput screen (HTS) of the GlaxoSmith-Kline compound collection was performed in an attempt toidentify chemical starting points, excluding alternative substrate

Received: June 29, 2015Published: August 12, 2015

Article

pubs.acs.org/jmc

© 2015 American Chemical Society 7021 DOI: 10.1021/acs.jmedchem.5b00992J. Med. Chem. 2015, 58, 7021−7056

pubs.acs.org/jmc

http://dx.doi.org/10.1021/acs.jmedchem.5b00992

Table 1. Human CD38 Enzyme Inhibition Data

Journal of Medicinal Chemistry Article

DOI: 10.1021/acs.jmedchem.5b00992J. Med. Chem. 2015, 58, 7021−7056

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inhibition. This effort yielded a number of weakly active CD38inhibitors with desirable kinetics against the human enzyme, in-cluding the recently published 6-thiazole quinoline hit series.18

Among these hits was a singleton quinoline carboxamide 1athat database mining revealed had no known protein targetassociated with it in historical GlaxoSmithKline assays.

As shown in Table 1, this inhibitor was a low micromolar inhibi-tor of human CD38 (IC50 = 7200 ± 2400 nM). Like the otherinhibitors disclosed in this article, the quinoline carboxamide 1aexhibits mixed inhibition of CD38, binding in the catalyticactive site (vide inf ra). Furthermore, preliminary pharmacoki-netic experiments revealed that quinoline carboxamide 1a had a

Table 1. continued

aSD = standard deviation; mean ± SD calculated from N ≥ 4, except where otherwise indicated; if the IC50 is higher than the highest testconcentration, then the curve fitting software ActivityBase returns a value with a “>” modifier; in some cases, the highest test concentration wasremoved from the curve analysis due to solubility or assay interference issues and hence the modified value may not be the same for everycompound. bMean ± SD calculated from N = 3; one additional value not included in statistics was reported as >30 000 nM. cMean ± SD calculatedfrom N = 2; two additional values not included in statistics were reported as >30 000 nM. dN = 3; two additional values exist with mean ± SD of25 000 ± 5300 nM. eMean ± SD calculated from N = 2. fN = 3; one additional value not included was reported as >10 000 nM. gOne additionalvalue was 14 000 nM. hOne additional value not included in statistics was reported as >3300 nM. iMean ± SD calculated from N = 4; one additionalvalue not included in statistics was reported as >30 000 nM.



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terminal i.v. clearance in mice of less than one-third of hepaticblood flow (Cl = 29 mL/min/kg) coupled with a decent murineoral bioavailability (F = 32%), as shown in Table 2. With itspositive attributes, inhibitor 1a was selected as a chemical smallmolecule lead for initiating the development of better CD38inhibitors. This article details the structure−activity relation-ships developed from screening hit 1a that resulted in thediscovery of two molecules with potencies and pharmacokineticproperties sufficient to serve as robust tool molecules for theinvestigation of CD38 enzyme biology in vivo.

■ CHEMISTRYThe quinoline CD38 inhibitors were prepared by one of severalroutes, as depicted in Schemes 1−3. In one route, thermal ipsodisplacement of the 4-chloro substituent of commerciallyavailable quinoline 2a with commercially available amines orthiols afforded 4-amino- or 4-thioquinolines 3a−3k and 3m−3ac,as shown in Scheme 1. Bromoquinoline 3l was synthesizedfrom commercially available 8-bromo-2-methyl-4-quinolin-amine by alkylation with 3,6-dichloro-2-fluorobenzyl bromide.Subsequent palladium-mediated carbonylation of these quino-lines at the 8-bromo moiety, with amine trapping, provided thedesired 8-quinoline carboxamides 1a, 1f−1j, 1l, 1q, 1ah−1ai,1al−1bb, and 1be.Alternatively, Ullmann-like couplings of 8-bromoquinolines

with copper(I) cyanide yielded 8-quinoline carbonitriles 4a,4m, and 4r. In lieu of this method, the Ullmann-like couplingcould be carried out first, converting the 8-bromoquinoline5a to the 8-cyanoquinoline 6. Then, after transforming thehydroxyl substituent of 6 to the triflate 7 with trifluorometha-nesulfonic anhydride, subsequent displacement with commer-cially available amines provided the 8-quinoline carbonitriles4b−4g, 4j−4l, 4n−4q, and 4s−4ab. The 4-(2-cyanobenzylamino)-quinoline 4i was prepared via alkylation, with 2-(bromomethyl)-benzonitrile, of the 4-aminoquinoline 4h, synthesized fromacid-catalyzed hydrolysis of the 2,4-dimethoxybenzyl group ofquinoline carbonitrile 4g. The 4-amidoquinoline 4ac wasprepared from 4-amino-2-methyl-8-quinoline carbonitrile4h, via acylation, with 2,6-dichlorobenzoyl chloride. The4-alkoxyquinoline 4ad was prepared by base-promotedalkylation of 4-hydroxyquinoline 6 with 1,3-dichlorobenzylbromide. These cyanides could be hydrolyzed with basichydrogen peroxide to give the 8-quinoline carboxamides1c−1e, 1k, 1m−1p, 1r−1ag, 1aj−1ak, and 1bc−1bd. Quino-line carboxamide 1b was synthesized from quinoline

carboxamide 1l via acid-catalyzed removal of the para-methoxybenzyl group.The 6-substituted quinolines were prepared as shown in

Scheme 2. The 6-fluoroquinoline analogue 1bf was synthesizedfrom commercially available 2-bromo-4-fluoroaniline 8a. First,the aniline 8a was converted to the 4-hydroxyquinoline 5b viathermal Michael addition/Friedel−Crafts cyclization with aMeldrum’s acid derivative. Then, treatment of the hydrox-yquinoline 5b with phosphorus oxychloride provided the4-chloroquinoline 2b. Subsequent addition of 2,3,6-trichlor-obenzylamine to chloroquinoline 2b afforded the 4-amino-quinoline 3ad. Finally, palladium-mediated carbonylation ofbromoquinoline 3ad, with amine trapping, provided the desired8-quinoline carboxamides 1bf.

Table 2. Measured Physicochemical Properties and Mouse in Vivo PK Dataa

permb

(nm/s)FaSSIF(mg/mL)

Cyp 3A4pIC50

liver t1/2(min)

hERGpIC50 t1/2 (h)

Cl(mL/min/kg)

VSS(L/kg) F (%)

DNAUC(ng/h/mL)

1a 780 0.630 5.0 44 6.3B 3.1 29 6.6 32 1941m 320 0.010 4.9 113 4.2 16 4.6 18 1961q 80 <0.001 5.4 40 1.8 22 3.1 49 3871v 390 0.005 5.1 19 3.1 53 6.4 34 1131ag 400 0.012 5.0 30 5.0 74 19 32 861ah 420 0.095 4.9 >90 6.4Q 4.1 24 6.4 35 2601ai 170 0.0014 44 6.3Q 18 3.5 4.9 17 7681am 280 5.4 33 4.0 24 4.2 64 437

aMice were dosed i.v. (2.0 mg/kg) or p.o. (10 mg/kg). bArtificial membrane permeability assay: A 1.8% lipid (phosphatidyl choline, egg) in 1%cholesterol decane solution was applied to a Millicell 96-well, 0.4 μm, PCF culture plate. 250 and 100 μL of 50 mM phosphate buffer, pH 7.4, with0.5% encapsin was applied to the donor and receiver compartments, respectively. 2.5 μL of a 10 mM stock solution of compound in DMSO wasadded to the donor compartment. The assay was incubated at room temperature for 3 h. Samples from both donor and receiver compartments wereanalyzed by HPLC with UV detection at 215 and 254 nm, and permeability was calculated.

Scheme 1. Synthesis of 4-Substituted QuinolineCarboxamidesa

aReagents and conditions: (a) R1R2XH, iPr2NEt or K2CO3, DMSO,DMF or NMP, 130−160 °C, 11−82%; (b) Pd2(dba)3 or Pd(OAc)2,1,1′-bis(diphenylphosphino)ferrocene or Ph2P(CH2)3PPh2 (dppp),CO, iPr2NEt, (Me3Si)2NH, DMF, 110 °C, 13−81%; (c) CuCN, DMFor DMA, 140−160 °C, 67−98%; (d) Tf2O, 2,6-lutidine, CH2Cl2, −30to 25 °C, 82%; (e) R1R2NH, K2CO3, THF, 75−90 °C, 15−81%; (f)R1Br, NaH or K2CO3, DMF, 70 °C 15−99%; (g) TFA, 99%; (h) 2,6-dichlorobenzoic acid, SOCl2, 70 °C; 4h, LHMDS, THF, −75 °C, 51%;(i) NaOH or KOH, 30% H2O2, DMSO, 8−82%.



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In an analogous manner to 5b, the 6-bromo-4-hydroxyquino-line 5c was synthesized from methyl 2-amino-5-bromobenzoate8b and methyl acetoacetate. Then, heating the hydroxy-quinoline 5c with phosphorus oxychloride provided the4-chloroquinoline 2c. A palladium-mediated cross-coupling of6-bromoquinoline 2c with potassium methyltrifluoroborateafforded the 6-methylquinoline 2d. Subsequently, heating theester 2d with ammonia provided the quinoline carboxamide 2e.Finally, thermal ipso displacement of the 4-chloro substituent of4-chloroquinoline 2e with 2,6-dimethylbenzylamine gave the6-methylquinoline carboxamide 1bg. Alternatively, aminolysisof the ester 2c provided the 6-bromoquinoline carboxamide 2f,which was converted to the CD38 analogue 1bh via thermalipso displacement of the 4-chloro substituent. The 6-phenyl-quinoline analogue 1bi was made in a similar manner to the6-methylquinoline 1bg via Suzuki cross-coupling of the6-bromoquinoline 2f with phenylboronic acid to provide the6-phenylquinoline 2g, followed by displacement of the 4-chlorosubstituent with 2,6-dimethylbenzylamine.As shown in Scheme 3, the 8-bromoquinoline 1bk was

prepared in a similar manner as above from 4-chloroquinoline2a and 2,3-dichlorobenzylamine. Subsequent palladium-mediatedcarbonylation of this quinoline at the 8-bromo moiety, followedby methylamine, dimethylamine, or methanol trapping,provided the desired 8-quinoline carboxamides/carboxylate1bl−bn. Base-catalyzed hydrolysis of quinoline carboxylate1bn with lithium hydroxide afforded the 8-quinoline carboxylicacid 1bo. Alternatively, lithium borohydride-mediated reduc-tion of quinoline carboxylate 1bn provided the 8-quinolinealcohol 1bp. Furthermore, this primary alcohol could beconverted to the primary amine 1bq via displacement ofthe in situ generated mesylate with ammonia. Treatment of the

8-quinoline carboxamide 1q, derived from 1bk by carbon-ylation and amine trapping, with Belleau’s reagent gave thequinoline nitrile 1br instead of the expected quinolinethioamide. In a like manner, an attempt to produce the8-quinoline boronic acid via palladium-mediated cross-couplingwith bis(pinacolato)diborane only gave the quinoline 1bj viahydropalladation of the aryl bromide. Finally, the quinolinesulfonamide 1bs was prepared via amidation of the knownsulfonyl chloride 2h19 with ammonia, giving the quinoline 2i,followed by ipso displacement of the 4-chloro moiety with2,3-dichlorobenzylamine.

■ RESULTS AND DISCUSSIONThe structure−activity relationships of the quinoline analoguesare depicted in Table 1. As the 4-aminoquinoline carboxamide1b did not inhibit CD38 up to concentrations of 0.03 mM, thebenzyl moiety in a compound such as 1a was clearly importantfor inhibitory activity. The unsubstituted benzyl analogue 1cwas a less potent CD38 inhibitor than the initial HTS hit 1a.With these results, it was decided to employ a Topliss-likeapproach on the phenyl moiety of the benzylic group in orderto identify optimal substitutions that maximized bindinginteractions of this area of the ligand with the CD38 enzymeand provided improved potency.20 All monosubstituted chloro,methyl, and methoxy derivatives were prepared. The chloro-substituted inhibitors 1e, 1h, and 1k were equal or betterinhibitors of CD38 than the methylated analogues 1d, 1g, and1j or the methoxy derivatives 1f, 1i, and 1l, respectively, with

Scheme 2. Synthesis of 6-Substituted QuinolineCarboxamidesa

aReagents and conditions: (a) 2,2-dimethyl-5-[1-(methylthio)-ethylidene]-1,3-dioxane-4,6-dione, Ph2O, microwave, 240 °C, 19%;(b) CH3COCH2COOCH3, PPA, 160 °C, 16%; (c) POCl3, 80−90 °C,42−77%; (d) KCH3BF3 or PhB(OH)2, Cs2CO3 or K2CO3,PdCl2(dppf) or (PPh3)2PdCl2, THF, 85 °C, 45−67%; (e) NH3,MeOH, 100 °C, 37−39%; (f) R1R2NH, 6 N HCl (aq) or iPr2NEt,NMP or DMSO, microwave, 150 °C, 5−65%; (g) Pd(OAc)2,Ph2P(CH2)3PPh2 (dppp), CO, iPr2NEt, (Me3Si)2NH, 110 °C, 53%.

Scheme 3. Synthesis of 8-Substituted Quinolinesa

aReagents and conditions: (a) 2,3-dichlorobenzylamine, iPr2NEt,DMSO or NMP, 150 °C, 47−75%; (b) Pd(OAc)2, Ph2P(CH2)3PPh2(dppp), CO, iPr2NEt, (Me3Si)2NH, MeNH2, Me2NH, or MeOH,110 °C, 47−66%; (c) LiOH, THF, MeOH, H2O, rt, 57%; (d) LiBH4,THF, rt, 64%; (e) Ms2O, THF, rt, NH3, 29%; (f) Belleau’s reagent,1,4-dioxane, 100 °C, 28%; (g) PdCl2(dppf), (OCMe2CMe2O)2B2,KOAc, 1,4-dioxane, 100 °C, 45%; (h) NH3 in dioxane, 60 °C, 82%.



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the ortho-chloro analogue 1e being the most potent inhibitor.These results suggest that the protein prefers electron-withdrawing groups and/or hydrophobic groups in this region.With these results in mind, several more ortho derivatives weresynthesized, with the trifluoromethyl moiety 1m and the bromoderivative 1n being equipotent to the chloro derivative 1e;however, the carboxamide derivative 1o was inactive.To further explore the phenyl ring SAR, all permutations

of the dichloro and dimethyl analogues were prepared. Thestarting 2,6-dimethyl lead 1a was equal or more potent thanthe 2,3- (1p), 2,4- (1r), 2,5- (1t), 3,4- (1w), and 3,5-dimethylquinolines (1y). Similarly, the 2,6-dichloro inhibitor 1vwas also more potent than the 2,4- (1s), 2,5- (1u), 3,4- (1x),and 3,5-dichloroquinolines (1z), whereas the 2,3-dichloroqui-noline (1q) was slightly more potent than 1v. As previouslydemonstrated, chloro substitution was favored over methylsubstitution in these analogues. Since ortho derivatives affordedgreater activity, the favored binding mode of the ligand in theprotein may be one in which the out-of-plane conformation ofthe benzylic moiety is preferred.Several 2,3-disubstituted benzyl analogues (1aa−1ad)

were prepared in an attempt to increase the potency of thesubmicromolar inhibitor 1q. However, all four of the preparedcompounds, the 2-fluoro-3-chloro derivative 1aa, the 2-methyl-3-chloro derivative 1ab, the 2-fluoro-3-trifluoromethyl deriva-tive 1ac, and the α-naphthyl derivative 1ad, were less potentthan the 2,3-dichloro derivative 1q. In a like manner, several2,6-disubstituted benzyl analogues were synthesized to furtherexplore the SAR of the submicromolar inhibitor 1v. Thischemistry effort enriched the understanding of the SAR, as the2-chloro-6-fluoro derivative 1af and the 2-trifluoromethyl-6-fluoro derivative 1ah exhibited similar activity to the 2,6-dichloro derivative 1v, whereas the 2,6-difluoro derivative 1aeand the 2-chloro-6-methyl derivative 1ag were less active.Furthermore, in an attempt to enhance the potencies of the 2,3-dichloro compound 1q and 2,6-dichloro compound 1v, the2,3,6-trichloro analogue 1ai was prepared. This compoundproved to be a more potent CD38 inhibitor than either 1qor 1v. Several more 2,3,6-trisubstituted benzyl analogues weresynthesized. These efforts revealed three additional equipotentderivatives, the 2-chloro-3,6-difluoro analogue 1ak, the 2,3-dichloro-6-fluoro analogue 1am, and the 2-chloro-3-methyl-6-fluoro analogue 1an. The 2,6-difluoro-3-chloro compound 1ajand 2-fluoro-3,6-dichloro compound 1al were also prepared;however, the potencies of these compounds were no betterthan their 2,6-comparators 1ae and 1af.The most potent benzyl-substituted inhibitors (e.g., 1ai)

contain hydrophobic moieties, resulting in compounds withlimited aqueous solubility. Therefore, heteroaryl isosteric re-placements of the phenyl ring were explored with the aspirationof enhancing the drug properties, such as solubility, of theresulting compounds while maintaining their CD38 activities.As such, four aza-analogues were prepared, the 2-trifluor-omethyl-6-aza derivative 1ao, the 2-trifluoromethyl-5-azaderivative 1ap, the 2-chloro-4-aza derivative 1aq, and the2-trifluoromethyl-3-aza derivative 1ar. Not surprisingly, becausethese pyridine derivatives require a higher desolvation energywhen binding to the enzyme than do their correspondingphenyl derivatives, many of these analogues were less activethan their comparators 1e and 1m. The most potent of thesepyridine compounds was 1ar, which likely has a lower desolva-tion energy than the other pyridine analogues due to theshielding of its nitrogen lone pair by the adjacent hydrophobic

trifluoromethyl group. Additionally, two 5-membered ringheteroaryl derivatives were synthesized. In SAR similar to thepyridine series, both the thiophene 1as and the isoxazole 1atwere poorer inhibitors when compared to the correspondingcompounds 1e and 1a, respectively.It has been observed that compounds containing greater

numbers of sp3 centers are more soluble than their more planarcounterparts. One hypothesis that attempts to rationalize thisphenomenon is that compounds containing sp3 centers donot pack in a crystalline lattice as well as compounds containingmore planar sp2 centers. For less planar compounds, thissituation results in lower crystallization energies and leads tofaster dissolutions in bulk solvents per unit surface area.Under this hypothesis, the synthesis of saturated ring isosteresof the phenyl ring was undertaken, with the ultimate goalof enhancing the solubility of the resulting compounds.The cyclohexyl analogue 1au was prepared and found to bemore potent than its corresponding phenyl analogue 1c;however, introduction of acylated or basic nitrogen piperidinerings into compounds such as 1av or 1aw was detrimental toinhibitory potency, possibly due to increased desolvationenergies.Substitution at the benzylic position of the 4-amino moiety

was also explored. Neither the (R)-chiral methyl analogue 1axnor the (S)-chiral methyl analogue 1ay were as active as theircomparators 1d and 1a, respectively. This potency loss likelyresults from an increased availability of potential rotamerpopulations as compared to the achiral inhibitor, rather thansome inability of the protein to accommodate the methylmoiety, because the conformationally constrained tetrahydro-naphthalene derivatives 1az and 1ba are better inhibitors thancompound 1d.Methylation of the benzylic nitrogen to give derivative 1bb

resulted in a large decrease in inhibitory activity relative to the2,6-dichloro analogue 1v. While a detrimental steric interactionbetween the methyl moiety and the protein could explain thesignificant decrease in potency, alternatively, the loss of thehydrogen could disrupt a key hydrogen-bonding interactionbetween the protein and the amino group. Interesting, althoughthe NH of the amide derivative 1bc could still act as ahydrogen-bond donor, this compound is also a poor inhibitorof CD38. In this particular case, though, the sp2 benzyliccenter may bias the conformation of the inhibitor, precludingits ability to adopt a conformation more suitable for hydrogenbonding. Both the benzyl ether derivative 1bd and the thioderivative 1be are poor inhibitors of CD38, but they shouldexist in conformations similar to the amine analogue 1v.Therefore, one can infer from these results that if a hydrogenbond exists between the protein and the ligand, then thatinteraction requires a hydrogen-bond donor and not anacceptor group.In addition to probing the SAR of the 4-position of the

quinoline ring, chemistry explorations were also focused onthe 6-position of the quinoline ring. Initially, three analogueswere prepared, the 6-methyl derivative 1bg, the 6-bromoderivative 1bh, and the 6-phenyl derivative 1bi. All of theseanalogues proved to be less potent than the initial HTS hit 1a,with the 6-methyl analogue 1bg being approximately 4-fold lesspotent. Subsequently, a 6-fluoro derivative 1bf was synthesizedwith the aim of improving metabolic stability. Surprisingly, thiscompound was slightly more active than its comparator 1ai.As shown in Table 1, any isosteric replacement of the

carboxamide at the 8-position of the quinoline ring provided



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compounds with little to no activity against CD38. Removal ofthe carboxamide, for example, analogue 1bj, resulted incompounds with no inhibitory activity. Furthermore, the8-bromo 1bk, the 8-methyl ester 1bn, the carboxylate 1bo,the 8-methyl alcohol 1bp, the 8-methyl amine 1bq, and the8-nitrile 1br derivatives exhibited no inhibitory activity atconcentrations as high as 30 000 nM. Moreover, the N-methylamide 1bl and the N,N-dimethyl amide 1bm provide no activityagainst the CD38 enzyme. Only the primary sulfonamide 1bsexhibited any inhibition, but it was over 10-fold less potent thatits congener 1q. Clearly, there is something special about thebinding interaction of the carboxamide with CD38.During the chemical exploration of this series, co-crystal

structures of quinoline carboxamides 1a and 1bf bound tohuman CD38 and ADPR or 5-phosphoribose, respectively,were obtained. Depictions of the binding complex of CD38 andthese compounds are illustrated in Figures 1 and 2. These structures

provide insight into the catalytic motif required for theenzyme’s recognition of CD38 substrates as well as revealthe binding modes of this class of CD38 inhibitors. Asillustrated in both structures, the nitrogen of the carboxamidegroups hydrogen bonds to the carboxylate side chains ofboth 146Glu and 155Asp. Furthermore, in each compound, thecarboxamide is coplanar with the quinoline ring, facilitating aninternal hydrogen bond between the protonated basic quinolinenitrogen and a lone pair of the carbonyl oxygen of thecarboxamide. Additionally, the quinoline ring forms a π−π face-to-face stacking interaction with the indole ring of 189Trp,providing increased binding affinity for the inhibitor. Thecoplanar 8-carboxamide group facilitates this interaction,withdrawing electron density from the quinoline ring andimproving the interaction with the π-cloud of the indole ring.Moreover, the hydrogen of the 4-benzyl amine provides for ahydrogen bond to the side chain hydroxyl oxygen of 221Thr.The ortho substituents of the 4-benzyl ring induces andstabilizes a near perpendicular conformation of the phenyl

ring and biases the ligand conformation resulting in a suitablebinding affinity for CD38. Additionally, this conformationallows for the formation of a triple π−π−π stacking interactionamong the 4-benzyl ring, the adenine ring of the substrate, andthe indole ring of 176Trp. This conformation of the inhibitoralso provides better hydrophobic interaction between theortho- and meta-substituents of the 4-benzyl ring (e.g., 2,3-dichloro or 2-methyl moieties) and the lipophilic side chain of190Lys. As observed in the 1bf structure, the small 6-fluorogroup is easily accommodated in an equally small region be-tween the ligand and the ribose substrate. Larger groups such as6-phenyl and 6-bromo substituents cannot bind into this smallregion, thus explaining the poor activity of compoundscontaining these groups. Thus, these human CD38 co-crystalstructures bound with ligand and substrate not only provideprotein structural insight into the recognition, affinity, andcatalytic mechanism of the enzyme but also help to rationalizemuch of the SAR observed in the quinoline carboxamideinhibitor series.In addition to evaluating the pharmacokinetic parameters of

the HTS hit 1a, several of the more potent analogues also hadtheir pharmacokinetic and physiochemical properties deter-mined. These results are summarized in Table 2. The artificialmembrane permeabilities of the analogues, providing similarinformation as Madin-Darby canine kidney (MDCK) cellpermeabilities, were moderate to high, ranging from 80 to780 nm/s.21 In contrast and with the exception of the HTS hit1a (FaSSIF = 0.63 mg/mL), the aqueous solubilities in fastedstate-simulated intestinal fluid (FaSSIF) were low, rangingfrom 0.001 to 0.095 mg/mL.22 In general, these compoundsdisplayed modest potency at inhibiting the cytochrome P4503A4 enzyme, with pIC50’s ranging from 4.9 to 5.5, providinga small therapeutic window relative to the compound’smodest CD38 inhibitory potency. Furthermore, select inhib-itors exhibited similar activity to that against CD38 in a humanether-a-go-go-related gene ion channel (hERG) binding assay,limiting their development potential.23 The in vitro half-lives of

Figure 1. Ligand binding domain of the X-ray co-crystal structure of1a complexed with CD38 E226Q and ADPR. The CD38 carbons arecolored green, with inhibitor 1a carbons colored cyan and ADPRcarbons colored magenta. Hydrogen bonds are depicted as yellowdashed lines. The coordinates have been deposited in the BrookhavenProtein Data Bank (PDB code 4XJT). This figure was generated usingPyMOL (The PyMOL Molecular Graphics System, version 1.7.4,Schrodinger, LLC).

Figure 2. Ligand binding domain of the X-ray co-crystal structure of1bf complexed with wild-type CD38 and the oxonium remnant of(2S,3R,4R)-2-deoxy-2-fluoro-D-ribose 5-phosphate (FR5P). The CD38carbons are colored green, with inhibitor 1bf carbons colored blue andFR5P colored magenta. Hydrogen bonds are depicted as yellowdashed lines. The coordinates have been deposited in the BrookhavenProtein Data Bank (PDB code 4XJS). This figure was generated usingPyMOL (The PyMOL Molecular Graphics System, version 1.7.4Schrodinger, LLC).



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the analogues in murine S9 liver slices did not correlate withtheir in vivo parameters in mice, precluding useful predictions.However, all but two inhibitors exhibited clearances of less thanone-third of hepatic blood flow (Cl = 3.5 to 29 mL/min/kg)and had high steady-state volumes of distribution (VSS = 3.1 to19 L/kg), which lead to acceptable terminal half-lives in mice.Oral bioavailabilities ranged from 17 to 64%. Several of thesubmicromolar CD38 analogues, including 1q, 1ah, 1ai, and1am, provided oral dose normalized area under the curveexposures greater than 250 ng/h/mL, making them acceptablefor in vivo studies.Two of these inhibitors, 1ah (mouse CD38 IC50 = 115 ±

50 nM) and 1ai (mouse CD38 IC50 = 46 ± 28 nM), wereselected as tool compounds to explore the pharmacodynamicsof this class of CD38 inhibitor. Similar to GSK’s 6-thiazolequinoline analogues, these inhibitors are more potent versusthe mouse CD38 enzyme compared to the human version.18

Diet-induced obese (DIO) mice (60% high fat diet), whichexhibit a deficit of NAD levels relative to that of lean controls,were dosed with inhibitor 1ah or 1ai (30 mg/kg), and changesin NAD levels were measured in liver and gastrocnemiusmuscle at 2 and 6 h postdose and compared to control mice.As illustrated in Table 3, NAD levels were significantly increased

at both the 2 and 6 h time points for inhibitor 1ah in liver(1483 and 595%, respectively) over control animals and forinhibitor 1ai in liver (515 and 224%, respectively) over controlanimals. The NAD levels were also elevated in gastrocnemiusmuscle, although to a smaller extent for inhibitor 1ah (283 and198% respectively, versus controls) and for inhibitor 1ai (219and 200%, respectively, versus controls) relative to liver. Thisstudy demonstrates that inhibition of CD38 in vivo with smallmolecule inhibitors elevates NAD tissue levels and these inhibitorscould be utilized to explore the therapeutic potential of NADenhancement in NAD deficient animal models of disease.

■ CONCLUSIONSIn summary, starting from a single, weakly active high-throughput screening hit, a series of quinoline carboxamidehuman CD38 inhibitors was iteratively prepared by employingfeedback from structure−activity relationships and observingthe binding conformations of inhibitors in co-crystal structureswith CD38. These efforts led to the identification of severalsubmicromolar, orally bioavailable CD38 tool compounds.Two of the inhibitors, 1ah and 1ai, were utilized in vivoto demonstrate pharmacodynamic elevation of tissue NADlevels in a DIO mouse model. Similar to 4-(((1R,4R)-4-(2-methoxyethoxy)cyclohexyl)amino)-1-methyl-6-(thiazol-5-yl)-quinolin-2(1H)-one,18 these chemical tools will allow for the

exploration of the therapeutic consequences of NAD modula-tion in NAD deficient animal models of disease, potentiallyrevealing human diseases that could be treated with CD38modulation.

■ EXPERIMENTAL SECTIONAll commercial chemicals and solvents were reagent grade and wereused without further purification unless otherwise specified. Thefollowing solvents and reagents have been abbreviated: tetrahydrofur-an (THF), diethyl ether (Et2O), dimethyl sulfoxide (DMSO), ethylacetate (EtOAc), dichloromethane (CH2Cl2), trifluoroacetic acid(TFA), N,N-dimethylformamide (DMF), methanol (MeOH), dime-thoxyethane (DME), N-methylpyrrolidine (NMP), acetonitrile(MeCN), chloroform (CHCl3), phosphorus oxychloride (POCl3),magnesium sulfate (MgSO4), triethylamine (Et3N), 2-propanol(iPrOH), diisopropylethylamine (iPr2NEt), sodium hydroxide(NaOH), t-butylmethyl ether (TBME), acetic acid (AcOH orHOAc), ethanol (EtOH), di-t-butyldicarbonate (BOC2O), sodiumsulfate (Na2SO4), N,N-dimethylacetamide (DMA), sodium bicarbonate(NaHCO3), potassium carbonate (K2CO3), 1-[bis(dimethylamino)-methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophos-phate (HATU), azobis(isobutyronitrile) (AIBN), 4-(2-hydroxyethyl)-piperazine-1-ethanesulfonic acid (HEPES), and dithiothreitol (DTT).All reactions except those in aqueous media were carried out with theuse of standard techniques for the exclusion of moisture. Reactionswere monitored by thin-layer chromatography (TLC) on 0.25 mmsilica gel plates (60F-254, E. Merck) and visualized with UV light,iodine, iodoplatinate, potassium permanganate, cerium molybdate,or 5% phosphomolybdic acid in 95% ethanol. Final compounds weretypically purified either by flash chromatography on silica gel(E. Merck 40−63 mm), radial chromatography on a Chromatotronusing prepared silica gel plates, or on a Biotage Horizon or ISCOCombiflash pump and fraction collection system utilizing prepackedsilica gel. Analytical purity was assessed either by reversed-phase high-performance liquid chromatography (RP-HPLC) using an Agilent1100 system equipped with a diode array spectrometer (λ range 190−400 nm) or by the LC-MS method detailed below. The stationaryphase was a Keystone Scientific BDS Hypersil C-18 column (5 μm,4.6 mm × 200 mm). The mobile phase employed 0.1% aqueous TFAwith MeCN as the organic modifier and a flow rate of 1.0 mL/min.Analytical data are reported as retention time (tR) in minutes andpercent purity. All compounds were found to be ≥95% pure unlessotherwise indicated. 1H NMR spectra were recorded on either aVarian UnityPlus 400 MHz or a Bruker Avance III 400 MHz NMRspectrometer. Chemical shifts are reported in parts per million (ppm,δ units). Coupling constants are reported in units of hertz (Hz).Splitting patterns are designated as s, singlet; d, doublet; t, triplet; q,quartet; p, pentet; h, hextet; m, multiplet; or br, broad. Low-resolutionmass spectra (MS) were recorded on a Waters SQD. The UPLCanalysis was conducted utilizing a Phenomenex Kinetex 1.7 μm 2.1 ×50 mm XB-C18 column at 40 °C. The gradient employed wascomposed of mobile phase A (water + 0.2% v/v formic acid) andmobile phase B (MeCN + 0.15% v/v FA). High-resolution MS wererecorded on a Waters (Micromass) LCT time-of-flight massspectrometer. Low-resolution mass spectra were obtained underelectrospray ionization (ESI), atmospheric pressure chemical ioniza-tion (APCI), or fast atom bombardment (FAB) methods. Combustionanalyses were performed by Robertson Microlit Laboratories, Inc.(Ledgewood, NJ).

8-Bromo-N-[(2,6-dimethylphenyl)methyl]-2-methyl-4-qui-nolinamine (3a).

Table 3. NAD Tissue Levels versus Controls after Treatmentwith CD38 Inhibitor 1ah or 1aia

tissuetime(h)

1ahNAD

level (%)

1ah NADSTDEV(n = 4)

1ai NADlevel (%)

1ai NADSTDEV(n = 4)

liver 2 1483 186 515 2136 595 150 224 75

gastrocnemius 2 283 4 219 246 198 31 200 18

aPercent control calculated based on area ratio of NAD+ tonicotinamide 1,N6-ethenoadenine dinucleotide (internal standard) ofcontrol animal tissue taken at the same time point.



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A solution of N,N-dimethylformamide (80 mL) containing 8-bromo-4-chloro-2-methylquinoline 2a (5.02 g, 19.6 mmol), 2,6-dimethylbenzyl-amine (5.29 g, 39.1 mmol), and potassium carbonate (5.41 g, 39.1 mmol)was heated at 160 °C in a sealed pressure vessel for 24 h. The darksolution was dissolved in ethyl acetate and then washed with water(2×). The solvent was removed in vacuo, and the residual slurry wastriturated with diethyl ether. The precipitated solid was collected viavacuum filtration to give 8-bromo-N-[(2,6-dimethylphenyl)methyl]-2-methyl-4-quinolinamine 3a (3.14 g, 8.84 mmol, 45% yield, 80% pureby NMR) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 8.32(d, 1H, J = 8 Hz), 7.92 (d, 1H, J = 7 Hz), 7.19−7.12 (m, 2H),7.11−7.06 (m, 2H), 7.01−6.95 (m, 1H), 6.63 (s, 1H), 4.36 (d,2H, J = 4 Hz), 2.55 (s, 3H), 2.33 (s, 6H); LC-MS (ES API) M +H = 355.4-{[(2,6-Dimethylphenyl)methyl]amino}-2-methyl-8-quinoli-

necarboxamide (1a).

Palladium acetate (382 mg, 1.70 mmol) was added to 8-bromo-N-[(2,6-dimethylphenyl)methyl]-2-methyl-4-quinolinamine 3a (3.02 g,8.50 mmol), 1,3-bis(diphenylphosphino)propane (1.05 g, 2.55 mmol),N,N-diisopropylethylamine (2.42 g, 18.7 mmol), and hexamethyldisi-lizane (9.60 g, 59.5 mmol) in N,N-dimethylformamide (70 mL), andthe reaction mixture was fitted with a carbon monoxide balloon andevacuated and purged with carbon monoxide (3×). The reaction wasthen heated at 110 °C overnight. The solution was allowed to cool, andthen the organics were dissolved in ethyl acetate. The organics werewashed with 1 M sodium hydroxide and water (2×), dried overmagnesium sulfate, and filtered. The solvent was removed in vacuo, andthe residual dark oil was purified by silica gel chromatography, elutingwith ethyl acetate/dichloromethane (2:3 to 9:1) to give an orange solid,which was further purified by reverse-phase high-performance liquidchromatography, eluting with acetonitrile/water with 0.05% trifluoro-acetic acid (5:95:100:0) to give 4-{[(2,6-dimethylphenyl)methyl]-amino}-2-methyl-8-quinolinecarboxamide 1a (1.13 g, 3.54 mmol, 42%yield) as a light yellow solid. 1H NMR (400 MHz, CD3SOCD3): δ11.21 (d, 1H, J = 4 Hz), 8.58−8.41 (m, 2H), 7.69 (d, 1H, J = 4 Hz),7.38 (t, 1H J = 8 Hz), 7.19−7.12 (m, 2H), 7.12−7.06 (m, 2H), 6.66 (s,1H), 4.39 (d, 2H, J = 4 Hz), 2.58 (s, 3H), 2.34 (s, 6H); HRMS:C20H21N3O requires M + H at m/z 320.1763; found, 320.1759; tR =0.66 min, 97.7% purity.4-Amino-2-methyl-8-quinolinecarboxamide (1b).

2-Methyl-4-({[4-(methyloxy)phenyl]methyl}amino)-8-quinolinecar-boxamide 1l (0.16 g, 0.498 mmol) was dissolved in trifluoroaceticacid (1 mL) and stirred at room temperature overnight. The reactionwas then concentrated under reduced pressure, and the residue waspurified by silica gel chromatography, eluting with methanol/dichloromethane (1:49 to 1:9) to give 4-amino-2-methyl-8-quinoline-carboxamide 1b (93 mg, 0.448 mmol, 90% yield) as a yellow solid. 1HNMR (400 MHz, CD3OD): δ 8.50 (d, 1H, J = 8 Hz), 8.46 (d, 1H, J =8 Hz), 7.72 (t, 1H, J = 8 Hz), 6.74 (s, 1H), 2.70 (s, 3H); HRMS:C11H11N3O requires M + H at m/z 202.0980; found, 202.0971; tR =0.37 min, 97.0% purity.

N-Benzyl-8-bromo-2-methylquinolin-4-amine (3b).

Benzylamine (627 mg, 5.85 mmol) was added to a solution of8-bromo-4-chloro-2-methylquinoline 2a (1.50 g, 5.85 mmol) in N,N-dimethylacetamide (10 mL) under nitrogen at room temperature.Then, potassium carbonate (1.616 g, 11.69 mmol) was added, and theresulting mixture was heated in a microwave at 160 °C for 5 h. Aftercooling, the reaction mixture was filtered. Then, methanol was added,and after stirring, the solid was collected by filtration to give N-benzyl-8-bromo-2-methylquinolin-4-amine 3b (850 mg, 2.60 mmol, 44%yield). LC-MS (ES API) M + H = 328.

4-(Benzylamino)-2-methylquinoline-8-carbonitrile (4a).

Copper(I) cyanide (465 mg, 5.20 mmol) was added to N-benzyl-8-bromo-2-methylquinolin-4-amine 3b (850 mg, 2.60 mmol) in N,N-dimethylacetamide (5 mL), and the reaction mixture was heated ina microwave at 160 °C for 5 h. After cooling, the reaction mixturewas diluted with methanol and the solid was collected by filtration.The solid was purified by preparative thin-layer chromatography(2:1 petroleum ether/ethyl acetate) to give 4-(benzylamino)-2-methylquinoline-8-carbonitrile 4a (560 mg, 2.049 mmol, 79% yield).LC-MS (LC-ES) M + H = 274.

4-(Benzylamino)-2-methylquinoline-8-carboxamide (1c).

Potassium hydroxide (230 mg, 4.10 mmol) was added to 4-(benzy-lamino)-2-methylquinoline-8-carbonitrile 4a (560 mg, 2.049 mmol)in dimethyl sulfoxide (15 mL) at 0 °C. Then, 30% hydrogen peroxide(697 mg, 20.49 mmol) was added dropwise over 5 min. The reac-tion mixture was stirred at room temperature overnight and thendiluted with water, and the solid was collected by filtration to give4-(benzylamino)-2-methylquinoline-8-carboxamide 1c (490 mg, 1.682mmol, 82% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.13 (br d,1H, J = 4 Hz), 8.52−8.42 (m, 2H), 8.98 (br t, 1H, J = 6 Hz), 7.66 (brd, 1H, = 4 Hz), 7.48 (t, 1H, J = 8 Hz), 7.38 (d, 2H, J = 7 Hz), 7.33 (t,2H, J = 7 Hz), 7.24 (t, 1H, J = 7 Hz), 6.38 (s, 1H), 4.57 (d, 2H, J =6 Hz), 2.43 (s, 3H); HRMS: C18H17N3O requires M + H at m/z292.1450; found, 292.1442; tR = 0.97 min, 97.5% purity.

4-Hydroxy-2-methylquinoline-8-carbonitrile (6).



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8-Bromo-2-methylquinolin-4-ol 5a (37.4 g, 157 mmol) and copper(I)cyanide (42.2 g, 471 mmol) were stirred in N,N-dimethylformamide(300 mL) at 140 °C for 12 h. After cooling to room temperature, thesolvent was removed in vacuo to afford 4-hydroxy-2-methylquinoline-8-carbonitrile 6 (31 g, 109 mmol, 70% yield). LC-MS (ES API)M + H = 185.8-Cyano-2-methylquinolin-4-yl trifluoromethanesulfonate (7).

To a solution of 4-hydroxy-2-methylquinoline-8-carbonitrile 6 (3 g,16.29 mmol) and 2,6-lutidine (4.36 g, 40.7 mmol) in dichloromethane(50 mL) under nitrogen at −30 °C was added a solution of trifluoro-methanesulfonic anhydride (5.50 mL, 32.6 mmol) in dichloromethane(50 mL) dropwise during 15 min. The reaction mixture was stirred atroom temperature overnight. The organic phase was washed with water(100 mL), 5% citric acid solution (100 mL), and saturated brine (100 mL).After drying over sodium sulfate and filtering, the solvent was evaporatedin vacuo to give the crude product as an off-white solid. Petroleum etherwas added to the solid, and it was filtered and dried to afford 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (4.2 g, 13.28 mmol, 82%yield) as a brown solid. LC-MS (ES API) M + H = 317.2-Methyl-4-(2-methylbenzylamino)quinoline-8-carbonitrile (4b).

o-Tolylmethanamine (380 mg, 3.14 mmol) was added to of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg, 0.999 mmol)in tetrahydrofuran (3 mL), and the reaction mixture was heated at80 °C overnight. After cooling, the reaction mixture was extracted byethyl acetate, washed with brine (3×), dried over magnesium sulfate,filtered, and concentrated. The residue was purified by thin-layerchromatography (5:2 petroleum ether/tetrahydrofuran) to give2-methyl-4-(2-methylbenzylamino)quinoline-8-carbonitrile 4b (105 mg,0.365 mmol, 37% yield) as yellow solid. LC-MS (LC-ES) M + H = 288.2-Methyl-4-(2-methylbenzylamino)quinoline-8-carboxa-

mide (1d).

Sodium hydroxide (121 mg, 3.03 mmol) was added to a solution of2-methyl-4-(2-methylbenzylamino)quinoline-8-carbonitrile 4b (105 mg,0.365 mmol) in dimethyl sulfoxide (12 mL) at room temperature.Then, 30% hydrogen peroxide (3 mL, 98 mmol) was added, and thereaction mixture was stirred for 2 h. Water (20 mL) was added, andthe reaction mixture was filtered, washed with water, and crystallizedfrom tetrahydrofuran and diethyl ether. Then, the crude product waspurified by reverse-phase high-performance liquid chromatography,eluting with acetonitrile/water with 0.05% trifluoroacetic acid togive 2-methyl-4-(2-methylbenzylamino)quinoline-8-carboxamide 1d(52 mg, 0.168 mmol, 46% yield) as a white solid. 1H NMR (400 MHz,CD3SOCD3): δ 11.14 (br d, 1H, J = 4 Hz), 8.49 (d, 2H, J = 8 Hz),

7.89 (br t, 1H, J = 5 Hz), 7.67 (br d, 1H, = 4 Hz), 7.48 (t, 1H, J = 8 Hz),7.24−7.08 (m, 4H), 6.33 (s, 1H), 4.52 (d, 2H, J = 5 Hz), 2.43 (s, 3H),2.37 (s, 3H); HRMS: C19H19N3O requires M + H at m/z 306.1606;found, 306.1607; tR = 1.79 min, 98.5% purity.

4-(2-Chlorobenzylamino)-2-methylquinoline-8-carbonitrile (4c).

A mixture of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (316 mg, 1.0 mmol) and (2-chlorophenyl)methanamine (424 mg,2.99 mmol) in tetrahydrofuran (5 mL) was stirred at 80 °C overnight.LC-MS monitoring of the reaction showed that some starting materialremained. The mixture was extracted by ethyl acetate and washed withbrine (3×). The organic layers were dried over magnesium sulfate andfiltered, and the solvent was removed under reduced pressure. Theresidue was purified by thin-layer chromatography (5:2 petroleumether/tetrahydrofuran) to give of 4-(2-chlorobenzylamino)-2-methyl-quinoline-8-carbonitrile 4c (180 mg, 0.58 mmol, 58% yield) as ayellow solid. LC-MS (ES API) M + H = 308.

2-Methyl-4-(2-methylbenzylamino)quinoline-8-carboxa-mide (1e).

To a solution of 4-(2-chlorobenzylamino)-2-methylquinoline-8-carbonitrile 4c (180 mg, 0.58 mmol) in dimethyl sulfoxide (10 mL)was added sodium hydroxide (180 mg, 4.50 mmol) at room temperature.Then, 30% hydrogen peroxide (2 mL, 19.6 mmol) was added after15 min. The mixture was stirred for 2 h, water (20 mL) was added, andthe mixture was filtered. The residue was washed with plenty of water andrecrystallized from tetrahydrofuran and diethyl ether. Then, the crudeproduct was purified by reverse-phase high-performance liquidchromatography, eluting with acetonitrile/water with 0.05% trifluoroaceticacid to give 2-methyl-4-(2-methylbenzylamino)quinoline-8-carboxamide1e (57 mg, 0.17 mmol, 29% yield) as a white solid. 1H NMR(400 MHz, CD3SOCD3): δ 11.10 (br d, 1H, J = 4 Hz), 8.51 (d, 1H,J = 8 Hz), 8.47 (d, 1H, J = 8 Hz), 8.04 (br t, 1H, J = 5 Hz), 7.70 (br d,1H, J = 4 Hz), 7.61−7.44 (m, 2H), 7.42−7.21 (m, 3H), 6.32 (s, 1H),4.63 (d, 2H, J = 5 Hz), 2.45 (s, 3H); HRMS: C18H16ClN3O requiresM + H at m/z 326.1060; found, 326.1056; tR = 1.81 min, 98.7% purity.

8-Bromo-N-(2-methoxybenzyl)-2-methylquinolin-4-amine (3c).

N,N-Diisopropylethylamine (0.313 mL, 1.795 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1535 g, 0.598 mmol) indimethyl sulfoxide (1.682 mL) at room temperature, followed by(2-methoxyphenyl)methanamine (0.123 g, 0.898 mmol), and the solutionwas heated at 150 °C for 64 h. The reaction mixture was poured intoether and methanol, washed with water, dried over magnesium sulfate,filtered, and concentrated. The residue was purified by silica gel



7030


chromatography, eluting with ethyl acetate/hexanes (2:3) to give8-bromo-N-(2-methoxybenzyl)-2-methylquinolin-4-amine 3c (0.1035 g,0.275 mmol, 46% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.25(d, 1H, J = 8 Hz), 7.94 (d, 1H, J = 7 Hz), 7.74 (t, 1H, J = 6 Hz), 7.30−7.20 (m, 2H), 7.14 (d, 1H, J = 6 Hz), 7.03 (d, 1H, J = 8 Hz), 6.85(t, 1H, J = 7 Hz), 6.27 (s, 1H), 4.47 (d, 2H, J = 6 Hz), 3.87 (s, 3H),2.39 (s, 3H); LC-MS (LC-ES) M + H = 357.4-((2-Methoxybenzyl)amino)-2-methylquinoline-8-carboxa-

mide (1f).

1,1′-Bis(diphenylphosphino)ferrocene (0.032 g, 0.058 mmol) andbis(trimethylsilyl)amine (0.917 mL, 4.35 mmol) were added to8-bromo-N-(2-methoxybenzyl)-2-methylquinolin-4-amine 3c (0.1035 g,0.290 mmol) in N,N-dimethylformamide (1.980 mL) at room temper-ature, followed by tris(dibenzylideneacetone)dipalladium(0) (0.027 g,0.029 mmol), and the solution was fitted with a carbon monoxide balloon,heated at 100 °C, and stirred for 2 h. The reaction mixture was cooled,poured into ether, washed with 1 N sodium hydroxide and water, driedover magnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with methanol/ethyl acetate(1:24) to give 4-((2-methoxybenzyl)amino)-2-methylquinoline-8-carbox-amide 1f (0.0442 g, 0.131 mmol, 45% yield). 1H NMR (400 MHz,CD3SOCD3): δ 11.14 (br d, 1H, J = 5 Hz), 8.48 (dd, 1H, J = 7, 1 Hz),8.45 (dd, 1H, J = 8, 1 Hz), 7.92 (br t, 1H, J = 6 Hz), 7.68 (d, 1H, J =5 Hz), 7.47 (t, 1H, J = 8 Hz), 7.24 (dt, 1H, J = 8, 1 Hz), 7.15 (d, 1H, J =8 Hz), 7.04 (t, 1H, J = 8 Hz), 6.86 (t, 1H, J = 8 Hz), 6.30 (s, 1H), 4.50 (d,2H, J = 5 Hz), 3.88 (s, 3H), 2.43 (s, 3H); HRMS: C19H19N3O2 requiresM + H at m/z 322.1555; found, 322.1551; tR = 0.50 min, 100.0% purity.8-Bromo-2-methyl-N-(3-methylbenzyl)quinolin-4-amine (3d).

N,N-Diisopropylethylamine (0.314 mL, 1.804 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1543 g, 0.601 mmol) indimethyl sulfoxide (1.691 mL) at room temperature, followed bym-tolylmethanamine (0.109 g, 0.902 mmol), and the solution was heatedat 150 °C for 64 h. The reaction mixture was poured into ether andmethanol, washed with water, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (1:2) to give 8-bromo-2-methyl-N-(3-methylbenzyl)quinolin-4-amine 3d (0.1398 g, 0.389 mmol, 65% yield).1H NMR (400 MHz, CD3SOCD3): δ 8.25 (d, 1H, J = 8 Hz), 7.94 (d, 1H,J = 7 Hz), 7.88 (br t, 1H, J = 6 Hz), 7.26 (t, 1H, J = 8 Hz), 7.24−7.12 (m,3H), 7.04 (d, 1H, J = 8 Hz), 6.34 (s, 1H), 4.50 (d, 2H, J = 6 Hz), 2.39 (s,3H), 2.26 (s, 3H); LC-MS (LC-ES) M + H = 342.2-Methyl-4-((3-methylbenzyl)amino)quinoline-8-carboxa-

mide (1g).

1,1′-Bis(diphenylphosphino)ferrocene (0.045 g, 0.082 mmol) andbis(trimethylsilyl)amine (1.296 mL, 6.15 mmol) were added to8-bromo-2-methyl-N-(3-methylbenzyl)quinolin-4-amine 3d (0.1398 g,0.410 mmol) in N,N-dimethylformamide (2.80 mL) at roomtemperature, followed by tris(dibenzylideneacetone)dipalladium(0)(0.038 g, 0.041 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 100 °C, and stirred for 4 h. The reactionmixture was cooled, poured into ether, washed with 1 N sodiumhydroxide and water, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography,eluting with methanol/ethyl acetate (1:49) to give 2-methyl-4-((3-methylbenzyl)amino)quinoline-8-carboxamide 1g (0.0459 g, 0.143 mmol,35% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.12 (br d, 1H, J =5 Hz), 8.48 (d, 1H, J = 7 Hz), 8.45 (d, 1H, J = 8 Hz), 8.05 (br t, 1H,J = 6 Hz), 7.67 (d, 1H, J = 5 Hz), 7.48 (t, 1H, J = 8 Hz), 7.24−7.14(m, 3H), 7.05 (d, 1H, J = 7 Hz), 6.37 (s, 1H), 4.52 (d, 2H, J = 6 Hz),2.43 (s, 3H), 2.27 (s, 3H); HRMS: C19H19N3O requires M + H at m/z306.1606; found, 306.1603; tR = 0.50 min, 99.0% purity.

8-Bromo-N-[(3-chlorophenyl)methyl]-2-methyl-4-quinolin-amine (3e).

N,N-Diisopropylethylamine (1.038 mL, 5.94 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5081 g, 1.981 mmol) indimethyl sulfoxide (5.20 mL) at room temperature, followed by3-chlorobenzylamine (0.363 mL, 2.97 mmol), and the solution washeated at 140 °C and stirred for 68 h. The reaction mixture wascooled, poured into ether, washed with water, dried over magnesiumsulfate, filtered, and concentrated. The residue was purified by silicagel chromatography, eluting with ethyl acetate/hexanes (1:3) togive 8-bromo-N-[(3-chlorophenyl)methyl]-2-methyl-4-quinolinamine3e (0.5460 g, 1.434 mmol, 72% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.24 (d, 1H, J = 8 Hz), 7.96 (d, 1H, J = 7 Hz),7.91 (br t, 1H, J = 6 Hz), 7.42 (s, 1H), 7.39−7.24 (m, 4H), 6.37(s, 1H), 4.56 (d, 2H, J = 6 Hz), 2.40 (s, 3H); LC-MS (LC-ES)M + H = 360.

4-{[(3-Chlorophenyl)methyl]amino}-2-methyl-8-quinoline-carboxamide (1h).

N,N-Diisopropylethylamine (0.221 mL, 1.264 mmol) and hexame-thyldisilazane (0.843 mL, 4.02 mmol) were added to 8-bromo-N-[(3-chlorophenyl)methyl]-2-methyl-4-quinolinamine 3e (0.2078 g,0.575 mmol) in N,N-dimethylformamide (4.68 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.071 g,0.172 mmol) and palladium(II) acetate (0.026 g, 0.115 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 4 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with methanol/ethyl acetate(1:19) to give 4-{[(3-chlorophenyl)methyl]amino}-2-methyl-8-quino-linecarboxamide 1h (0.0509 g, 0.148 mmol, 26% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.09 (br d, 1H, J = 4 Hz), 8.49 (d, 1H,J = 7 Hz), 8.44 (d, 1H, J = 8 Hz), 8.08 (br t, 1H, J = 6 Hz), 7.68 (br d,1H, J = 5 Hz), 7.49 (t, 1H, J = 8 Hz), 7.44 (s, 1H), 7.40−7.28 (m, 3H),



7031


6.40 (s, 1H), 4.58 (d, 2H, J = 6 Hz), 2.44 (s, 3H); HRMS:C18H16ClN3O requires M + H at m/z 326.1060; found, 326.1061;tR = 0.58 min, 100.0% purity.8-Bromo-N-(3-methoxybenzyl)-2-methylquinolin-4-amine (3f).

N,N-Diisopropylethylamine (0.316 mL, 1.814 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1551 g, 0.605 mmol) indimethyl sulfoxide (1.699 mL) at room temperature, followed by(3-methoxyphenyl)methanamine (0.124 g, 0.907 mmol), and thesolution was heated at 150 °C for 64 h. The reaction mixture waspoured into diethyl ether and methanol, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (2:3)to give 8-bromo-N-(3-methoxybenzyl)-2-methylquinolin-4-amine 3f(0.1213 g, 0.323 mmol, 53% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.25 (d, 1H, J = 8 Hz), 7.95 (d, 1H, J = 7 Hz),7.91 (br s, 1H), 7.27 (t, 1H, J = 8 Hz), 7.23 (t, 1H, J = 8 Hz), 6.95 (s,1H), 6.94 (d, 1H, J = 8 Hz), 6.80 (d, 1H, J = 8 Hz), 6.36 (s, 1H),4.51 (d, 2H, J = 6 Hz), 3.70 (s, 3H), 2.40 (s, 3H); LC-MS (LC-ES)M + H = 358.4-((3-Methoxybenzyl)amino)-2-methylquinoline-8-carboxa-

mide (1i).

1,1′-Bis(diphenylphosphino)ferrocene (0.019 g, 0.034 mmol) andbis(trimethylsilyl)amine (0.544 mL, 2.58 mmol) were added to8-bromo-N-(3-methoxybenzyl)-2-methylquinolin-4-amine 3f (0.0614 g,0.172 mmol) in N,N-dimethylformamide (1.175 mL) at roomtemperature, followed by tris(dibenzylideneacetone)dipalladium(0)(0.016 g, 0.017 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 100 °C, and stirred for 4 h. The reac-tion mixture was cooled, poured into ether, washed with 1 N sodiumhydroxide and water, dried over magnesium sulfate, filtered,and concentrated. The residue was purified by silica gel chromatog-raphy, eluting with methanol/ethyl acetate (1:49) to give 4-((3-methoxybenzyl)amino)-2-methylquinoline-8-carboxamide 1i (0.0341 g,0.101 mmol, 59% yield). 1H NMR (400 MHz, CD3SOCD3): δ11.12 (br d, 1H, J = 5 Hz), 8.48 (d, 1H, J = 7 Hz), 8.44 (d, 1H,J = 8 Hz), 8.06 (br t, 1H, J = 6 Hz), 7.67 (d, 1H, J = 5 Hz), 7.48 (t,1H, J = 8 Hz), 7.24 (t, 1H, J = 8 Hz), 6.96 (s, 1H), 6.95 (d, 1H,J = 6 Hz), 6.80 (dd, 1H, J = 7, 2 Hz), 6.38 (s, 1H), 4.53 (d, 2H,J = 6 Hz), 3.71 (s, 3H), 2.43 (s, 3H); HRMS: C19H19N3O2requires M + H at m/z 322.1555; found, 322.1555; tR = 0.50 min,100.0% purity.8-Bromo-2-methyl-N-(4-methylbenzyl)quinolin-4-amine (3g).

N,N-Diisopropylethylamine (0.311 mL, 1.783 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1525 g, 0.594 mmol) indimethyl sulfoxide (1.671 mL) at room temperature, followed byp-tolylmethanamine (0.108 g, 0.892 mmol), and the solution washeated at 150 °C for 8 h. The reaction mixture was poured into etherand methanol, washed with water, dried over magnesium sulfate,filtered, and concentrated. The residue was purified by silica gelchromatography, eluting with ethyl acetate/hexanes (3:7) to give8-bromo-2-methyl-N-(4-methylbenzyl)quinolin-4-amine 3g (0.1371 g,0.382 mmol, 64% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.24(d, 1H, J = 8 Hz), 7.94 (d, 1H, J = 7 Hz), 7.88 (br t, 1H, J = 6 Hz),7.26 (t, 1H, J = 8 Hz), 7.25 (d, 2H, J = 8 Hz), 7.12 (d, 2H, J = 8 Hz),6.33 (s, 1H), 4.49 (d, 2H, J = 6 Hz), 2.38 (s, 3H), 2.25 (s, 3H);LC-MS (LC-ES) M + H = 342.

2-Methyl-4-((4-methylbenzyl)amino)quinoline-8-carboxa-mide (1j).

1,1′-Bis(diphenylphosphino)ferrocene (0.045 g, 0.080 mmol) andbis(trimethylsilyl)amine (1.271 mL, 6.03 mmol) were added to8-bromo-2-methyl-N-(4-methylbenzyl)quinolin-4-amine 3g (0.1371 g,0.402 mmol) in N,N-dimethylformamide (2.75 mL) at roomtemperature, followed by tris(dibenzylideneacetone)dipalladium(0)(0.037 g, 0.040 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 100 °C, and stirred for 4 h. The reactionmixture was cooled, poured into ether, washed with 1 N sodiumhydroxide and water, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography,eluting with methanol/ethyl acetate (1:49) to give 2-methyl-4-((4-methylbenzyl)amino)quinoline-8-carboxamide 1j (0.0881 g, 0.274 mmol,68% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.13 (br d, 1H,J = 5 Hz), 8.47 (d, 1H, J = 7 Hz), 8.44 (dd, 1H, J = 8, 1 Hz), 8.06 (br t,1H, J = 6 Hz), 7.67 (d, 1H, J = 5 Hz), 7.47 (t, 1H, J = 8 Hz), 7.26 (d,2H, J = 8 Hz), 7.13 (d, 2H, J = 8 Hz), 6.36 (s, 1H), 4.51 (d, 2H,J = 6 Hz), 2.42 (s, 3H), 2.25 (s, 3H); HRMS: C19H19N3O requiresM + H at m/z 306.1606; found, 306.1605; tR = 0.53 min, 100.0%purity.

4-(4-Chlorobenzylamino)-2-methylquinoline-8-carbonitrile (4d).

(4-Chlorophenyl)methanamine (340 mg, 2.401 mmol) was added to8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (320 mg,1.012 mmol) in dimethyl sulfoxide (2 mL), and the reaction mixturewas heated at 80 °C overnight. The mixture was extracted by ethylacetate, washed with brine (3×), dried over magnesium sulfate,filtered, and concentrated. The residue was purified by preparativethin-layer chromatography (5:2 petroleum ether/tetrahydrofuran) togive 4-(4-chlorobenzylamino)-2-methylquinoline-8-carbonitrile 4d(110 mg, 0.357 mmol, 35% yield) as a yellow solid. LC-MS (LC-ES)M + H = 308.



7032


4-(4-Chlorobenzylamino)-2-methylquinoline-8-carboxa-mide (1k).

Sodium hydroxide (167 mg, 4.18 mmol) was added to a solution of4-(4-chlorobenzylamino)-2-methylquinoline-8-carbonitrile 4d (110 mg,0.357 mmol) in dimethyl sulfoxide (10 mL) at room temperature.Then, 30% hydrogen peroxide (2 mL, 19.58 mmol) was added, and thereaction mixture was stirred for 2 h. Water (20 mL) was added, and themixture was filtered. The residue was washed with water and crystallizedfrom tetrahydrofuran and diethyl ether. Then, the crude product waspurified by reverse-phase high-performance liquid chromatography, elutingwith acetonitrile/water with 0.05% trifluoroacetic acid to give 4-(4-chlorobenzylamino)-2-methylquinoline-8-carboxamide 1k (18 mg, 0.055mmol, 15% yield) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ11.10 (br d, 1H, J = 4 Hz), 8.48 (d, 1H, J = 7 Hz), 8.43 (d, 1H, J = 8 Hz),8.08 (br t, 1H, J = 6 Hz), 7.67 (br d, 1H, J = 4 Hz), 7.48 (t, 1H, J = 8 Hz),7.46−7.34 (m, 4H), 6.36 (s, 1H), 4.56 (d, 2H, J = 6 Hz), 2.43 (s, 3H);HRMS: C18H16ClN3O requires M + H at m/z 326.1060; found, 326.1060;tR = 1.81 min, 98.9% purity.8-Bromo-N-(4-methoxybenzyl)-2-methylquinolin-4-amine (3h).

N,N-Diisopropylethylamine (0.311 mL, 1.783 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1525 g, 0.594 mmol) indimethyl sulfoxide (1.671 mL) at room temperature, followed by(4-methoxyphenyl)methanamine (0.122 g, 0.892 mmol), and the solutionwas heated at 150 °C for 7 h. The reaction mixture was poured into etherand methanol, washed with water, dried over magnesium sulfate, filtered,and concentrated. The residue was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (2:3) to give 8-bromo-N-(4-methoxybenzyl)-2-methylquinolin-4-amine 3h (0.1213 g, 0.323 mmol,54% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.25 (d, 1H, J = 8 Hz),7.94 (d, 1H, J = 7 Hz), 7.86 (br s, 1H), 7.30 (d, 2H, J = 9 Hz), 7.25 (t,1H, J = 8 Hz), 6.88 (d, 2H, J = 9 Hz), 6.37 (s, 1H), 4.46 (d, 2H, J =6 Hz), 3.70 (s, 3H), 2.40 (s, 3H); LC-MS (LC-ES) M + H = 358.4-((4-Methoxybenzyl)amino)-2-methylquinoline-8-carboxa-

mide (1l).

1,1′-Bis(diphenylphosphino)ferrocene (0.018 g, 0.032 mmol) andbis(trimethylsilyl)amine (0.509 mL, 2.414 mmol) were added to8-bromo-N-(4-methoxybenzyl)-2-methylquinolin-4-amine 3h (0.0575 g,0.161 mmol) in N,N-dimethylformamide (1.100 mL) at room temper-ature, followed by tris(dibenzylideneacetone)dipalladium(0) (0.015 g,

0.016 mmol), and the solution was fitted with a carbon monoxide balloon,heated at 100 °C, and stirred for 2 h. The reaction mixture was cooled,poured into ether, washed with 1 N sodium hydroxide and water, driedover magnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with methanol/ethyl acetate (1:24) togive 4-((4-methoxybenzyl)amino)-2-methylquinoline-8-carboxamide 1l(0.0439 g, 0.130 mmol, 81% yield). 1H NMR (400 MHz, CD3SOCD3):δ 11.13 (br d, 1H, J = 5 Hz), 8.47 (d, 1H, J = 7 Hz), 8.43 (d, 1H, J =8 Hz), 8.02 (br t, 1H, J = 6 Hz), 7.67 (d, 1H, J = 5 Hz), 7.47 (t, 1H, J =8 Hz), 7.31 (d, 2H, J = 9 Hz), 6.89 (d, 2H, J = 9 Hz), 6.39 (s, 1H), 4.48 (d,2H, J = 6 Hz), 3.71 (s, 3H), 2.43 (s, 3H); HRMS: C19H19N3O2 requiresM + H at m/z 322.1555; found, 322.1560; tR = 0.50 min, 98.3% purity.

2-Methyl-4-(2-(trifluoromethyl)benzylamino)quinoline-8-carbonitrile (4e).

A solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (300 mg, 0.95 mmol) and (2-(trifluoromethyl)phenyl)methanamine(332 mg, 1.90 mmol) in dimethyl sulfoxide (5 mL) was stirred undernitrogen at 90 °C for 24 h, cooled, and poured into water. The organicswere extracted with ethyl acetate, washed with brine, concentrated, andpurified by preparative thin-layer chromatography (2:1 petroleum ether/ethyl acetate) to afford 2-methyl-4-(2-(trifluoromethyl)benzylamino)-quinoline-8-carbonitrile 4e (190 mg, 0.56 mmol, 59% yield) as a whitesolid. 1H NMR (400 MHz, CDCl3): δ 8.02 (br s, 1H), 8.01 (d, 1H, J =8 Hz), 7.76 (d, 1H, J = 8 Hz), 7.56−7.50 (m, 2H), 7.48−7.40 (m, 2H),6.36 (s, 1H), 4.78 (d, 2H, J = 5 Hz), 2.62 (s, 3H).

2-Methyl-4-(2-(trifluoromethyl)benzylamino)quinoline-8-carboxamide (1m).

To a mixture of 2-methyl-4-(2-(trifluoromethyl)benzylamino)quinoline-8-carbonitrile 4e (160 mg, 0.47 mmol) and sodium hydroxide (56.2 mg,1.41 mmol) in dimethyl sulfoxide was added 30% hydrogen peroxide(0.14 mL, 4.69 mmol) dropwise. The reaction was then stirred at roomtemperature overnight. The reaction mixture was poured into water andfiltered to give 2-methyl-4-(2-(trifluoromethyl)benzylamino)quinoline-8-carboxamide 1m (45 mg, 0.12 mmol, 26% yield) as a white solid. 1HNMR (400 MHz, CD3SOCD3): δ 11.08 (br d, 1H, J = 5 Hz), 8.53 (dd,1H, J = 8, 1 Hz), 8.49 (dd, 1H, J = 8, 1 Hz), 8.14 (br t, 1H, J = 6 Hz),7.81 (d, 1H, J = 8 Hz), 7.72 (br d, 1H, J = 5 Hz), 7.62 (t, 1H, J = 7 Hz),7.58−7.47 (m, 3H), 6.24 (s, 1H), 4.74 (d, 2H, J = 5 Hz), 2.43 (s, 3H);HRMS: C19H16F3N3O requires M + H at m/z 360.1323; found,360.1316; tR = 1.66 min, 99.8% purity.

4-(2-Bromobenzylamino)-2-methylquinoline-8-carbonitrile (4f).



7033


To a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (316 mg, 1.0 mmoL) in tetrahydrofuran (20 mL) stirred under nitrogenat room temperature was added (2-bromophenyl)methanamine (930 mg,5.0 mmol) dropwise during 1 min. The reaction mixture was stirred at80 °C overnight. The reaction mixture was partitioned between water(50 mL) and filtered, and the filtrate was dissolved in ethyl acetate andtetrahydrofuran and purified by preparative thin-layer chromatography (1:1petroleum ether/tetrahydrofuran) to obtain 4-(2-bromobenzylamino)-2-methylquinoline-8-carbonitrile 4f (190 mg, 0.49 mmol, 49% yield) as awhite solid. LC-MS (ES API) M + H = 352.4-(2-Bromobenzylamino)-2-methylquinoline-8-carboxa-

mide (1n).

To a solution of 4-(2-bromobenzylamino)-2-methylquinoline-8-carbonitrile 4f (150 mg, 0.43 mmol) and sodium hydroxide(68.1 mg, 1.70 mmol) in dimethyl sulfoxide (20 mL) under nitrogenat 0 °C was added hydrogen peroxide (5 mL, 163 mmol) dropwiseduring 5 min. The reaction mixture was stirred at room temperatureovernight. Water (50 mL) was added to the mixture, and the solutionwas filtered. The filtrate was washed with water twice and then driedin vacuo to obtain 4-(2-bromobenzylamino)-2-methylquinoline-8-carbox-amide 1n (75 mg, 0.20 mmol, 47% yield) as a white solid. 1H NMR(400 MHz, CD3SOCD3): δ 11.11 (br d, 1H, J = 4 Hz), 8.52 (dd, 1H, J =8, 1 Hz), 8.47 (d, 1H, J = 9 Hz), 8.06 (br t, 1H, J = 6 Hz), 7.80−7.60 (m,2H), 7.52 (t, 1H, J = 8 Hz), 7.43−7.15 (m, 3H), 6.30 (s, 1H), 4.59 (d,2H, J = 6 Hz), 2.45 (s, 3H); HRMS: C18H16BrN3O requires M + H atm/z 370.0555; found, 370.0550; tR = 1.66 min, 98.3% purity.4-({[2,4-Bis(methyloxy)phenyl]methyl}amino)-2-methyl-8-

quinolinecarbonitrile (4g).

1-[2,4-Bis(methyloxy)phenyl]methanamine (9.91 g, 59.3 mmol) wasadded to 8-cyano-2-methyl-4-quinolinyl trifluoromethanesulfonate7 (7.5 g, 23.71 mmol) in tetrahydrofuran (200 mL) under nitrogen,and the reaction mixture was heated at 75 °C for 12 h. The reactionmixture was concentrated, and the residue was purified by silica gelchromatography, eluting with acetone/petroleum ether (2:1) to give4-({[2,4-bis(methyloxy)phenyl]methyl}amino)-2-methyl-8-quinoline-carbonitrile 4g (3.0 g, 9.00 mmol, 38% yield) as a yellow solid. LC-MS(ES API) M + H = 334.4-Amino-2-methyl-8-quinolinecarbonitrile (4h).

Trifluoroacetic acid (50 mL) was added to 4-({[2,4-bis(methyloxy)-phenyl]methyl}amino)-2-methyl-8-quinolinecarbonitrile 4g (6.6 g,19.80 mmol), and the reaction mixture was stirred at for 1 h, thenconcentrated. The residue was washed with diethyl ether (100 mL),filtered, washed with saturated sodium bicarbonate, and filtered to give

4-amino-2-methyl-8-quinolinecarbonitrile 4h (4.0 g, 19.65 mmol, 99%yield) as a yellow solid. LC-MS (ES API) M + H = 184.

4-(2-Cyanobenzylamino)-2-methylquinoline-8-carbonitrile (4i).

2-(Bromomethyl)benzonitrile (1070 mg, 5.46 mmol) was added to4-amino-2-methylquinoline-8-carbonitrile 4h (500 mg, 2.73 mmol) intetrahydrofuran (15 mL), followed by potassium carbonate (754 mg,5.46 mmol), and the reaction mixture was heated under nitrogen at85 °C for overnight. The reaction mixture was filtered to remove thesolid, the solid was washed with tetrahydrofuran, and the filtrate wasconcentrated. The residue was purified by preparative thin-layerchromatography (1:1 petroleum ether/tetrahydrofuran) to give 4-(2-cyanobenzylamino)-2-methylquinoline-8-carbonitrile 4i (270 mg,0.905 mmol, 33% yield). LC-MS (ES API) M + H = 299.

4-(2-Carbamoylbenzylamino)-2-methylquinoline-8-carboxa-mide (1o).

Potassium hydroxide (203 mg, 3.62 mmol) was added to 4-(2-cyanobenzylamino)-2-methylquinoline-8-carbonitrile 4i (270 mg,0.905 mmol) in dimethyl sulfoxide (3 mL) at room temperature. Then,30% hydrogen peroxide (3 mL, 98 mmol) was added dropwise. Thereaction mixture was stirred for 2 h. The reaction mixture was diluted withwater, extracted with ethyl acetate (3×), washed with brine, dried overanhydrous sodium sulfate, filtered, and concentrated. The residue waspurified by preparative high-performance liquid chromatography, elutingwith acetonitrile/10 mM ammonium bicarbonate in water to give 4-(2-carbamoylbenzylamino)-2-methylquinoline-8-carboxamide 1o (58 mg,0.171 mmol, 19% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.12(br d, 1H, J = 5 Hz), 8.49 (dd, 1H, J = 7, 1 Hz), 8.40 (dd, 1H, J = 7,1 Hz), 8.03 (br t, 1H, J = 6 Hz), 7.98 (br s, 1H), 7.68 (br d, 1H, J =5 Hz), 7.57 (br s, 1H), 7.52−7.46 (m, 2H), 7.40−7.28 (m, 3H), 6.36 (s,1H), 4.72 (d, 2H, J = 6 Hz), 2.42 (s, 3H); HRMS: C19H18N4O2 requiresM + H at m/z 335.1508; found, 335.1511; tR = 1.33 min, 98.4% purity.

4-(2,3-Dimethylbenzylamino)-2-methylquinoline-8-carboni-trile (4j).

(2,3-Dimethylphenyl)methanamine (176 mg, 1.299 mmol) was addedto 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg,1 mmol) in tetrahydrofuran (6 mL) under nitrogen. Then, potassiumcarbonate (276 mg, 1.998 mmol) was added, and the reaction mixturewas heated at 80 °C overnight. Water (10 mL) was added, and the solidwas collected by filtration to give 4-(2,3-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4j (100 mg, 0.285 mmol, 29% yield).LC-MS (ES API) M + H = 302.



7034


(2,3-Dimethylbenzylamino)-2-methylquinoline-8-carboxa-mide trifluoroacetate (1p).

Sodium hydroxide (26.5 mg, 0.664 mmol) was added to 4-(2,3-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4j (100 mg,0.332 mmol) in dimethyl sulfoxide (5 mL). Then, 30% hydrogenperoxide (1.881 mL, 16.59 mmol) was added, and the reaction mixturewas allowed to stir overnight. The reaction mixture was diluted withwater (20 mL), and the resulting precipitant was collected by filtration.The residue was purified by reverse-phase preparative high-perform-ance liquid chromatography, eluting with acetonitrile/water with0.01% trifluoroacetic acid (5:95 to 95:5) to give (2,3-dimethylbenzy-lamino)-2-methylquinoline-8-carboxamide trifluoroacetate 1p (50 mg,0.115 mmol, 35% yield). 1H NMR (400 MHz, CD3SOCD3): δ 14.21(br s, 1H), 9.66 (br s, 1H), 8.83 (br s, 1H), 8.78 (d, 1H, J = 8 Hz),8.49 (d, 1H, J = 7 Hz), 8.27 (s, 1H), 7.76 (br s, 1H), 7.11 (s, 1H), 7.04(s, 2H), 6.77 (s, 1H), 4.73 (d, 2H, J = 4 Hz), 2.63 (s, 3H), 2.27 (s,3H), 2.23 (s, 3H); HRMS: C20H21N3O requires M + H at m/z320.1763; found, 320.1759; tR = 1.68 min, 96.2% purity.4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-quinoli-

necarboxamide (1q).

N,N-Diisopropylethylamine (0.491 mL, 2.81 mmol) and hexamethyl-disilazane (1.873 mL, 8.94 mmol) were added to 8-bromo-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quinolinamine 1bk (0.5057 g,1.277 mmol) in N,N-dimethylformamide (4.02 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.158 g,0.383 mmol) and palladium(II) acetate (0.057 g, 0.255 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 4 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate to give4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxa-mide 1q (0.1894 g, 0.499 mmol, 39% yield). 1H NMR (400 MHz,CD3SOCD3): δ 11.09 (br d, 1H, J = 4 Hz), 8.50 (d, 1H, J = 7 Hz),8.45 (d, 1H, J = 8 Hz), 8.04 (br t, 1H, J = 6 Hz), 7.69 (br d, 1H, J =4 Hz), 7.57 (d, 1H, J = 8 Hz), 7.51 (d, 1H, J = 8 Hz), 7.31 (t, 1H, J =8 Hz), 7.26 (d, 1H, J = 7 Hz), 6.33 (s, 1H), 4.65 (d, 2H, J = 6 Hz),2.44 (s, 3H); HRMS: C18H15Cl2N3O requires M + H at m/z360.0670; found, 360.0671; tR = 0.70 min, 100.0% purity.4-(2,4-Dimethylbenzylamino)-2-methylquinoline-8-carboni-

trile (4k).

(2,4-Dimethylphenyl)methanamine (270 mg, 1.998 mmol) was addedto a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethane-sulfonate 7 (316 mg, 0.999 mmol) in tetrahydrofuran (10 mL)under nitrogen at room temperature. Then, potassium carbonate(276 mg, 1.998 mmol) was added, and the reaction mixture washeated at 75 °C overnight. The reaction mixture was filtered, washedwith tetrahydrofuran (3×), and purified by preparative thin-layerchromatography (1:2 tetrahydrofuran/petroleum ether) to give 4-(2,4-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4k (140 mg,0.465 mmol, 46% yield). LC-MS (ES API) M + H = 302.

4-(2,4-Dimethylbenzylamino)-2-methylquinoline-8-carboxa-mide trifluoroacetate (1r).

Sodium hydroxide (37.2 mg, 0.929 mmol) was added to a solution of4-(2,4-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4k(140 mg, 0.465 mmol) in dimethyl sulfoxide (3 mL) under nitrogenat room temperature. Then, 30% hydrogen peroxide (3 mL, 98 mmol)was added, and the reaction mixture was stirred for 1 h. The reactionmixture was diluted with water and filtered, the solid was washed withwater (3×), and the solid was dried under reduced pressure. Theresidue was further purified by preparative high-performance liquidchromatography, eluting with acetonitrile/water with 0.01% trifluoro-acetic acid (5:95 to 95:5) to give 4-(2,4-dimethylbenzylamino)-2-methylquinoline-8-carboxamide trifluoroacetate 1r (65 mg, 0.145 mmol,31% yield). 1H NMR (400 MHz, CD3SOCD3): δ 14.21 (br s, 1H),9.63 (br s, 1H), 8.83 (br s, 1H), 8.78 (d, 1H, J = 8 Hz), 8.50 (d, 1H,J = 8 Hz), 8.27 (br s, 1H), 7.78 (t, 1H, J = 8 Hz), 7.08 (d, 1H,J = 8 Hz), 7.07 (s, 1H), 6.96 (d, 1H, J = 8 Hz), 6.77 (s, 1H), 4.69 (d,2H, J = 5 Hz), 2.64 (s, 3H), 2.33 (s, 3H), 2.25 (s, 3H); HRMS:C20H21N3O requires M + H at m/z 320.1763; found, 320.1756; tR =1.37 min, 96.8% purity.

4-(2,4-Dichlorobenzylamino)-2-methylquinoline-8-carboni-trile (4l).

To a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesul-fonate 7 (316 mg, 1.0 mmol) and (2,4-dichlorophenyl)methanamine(264 mg, 1.50 mmol) in tetrahydrofuran (5 mL) stirred undernitrogen at room temperature was added solid potassium carbonate(276 mg, 2.0 mmol). The reaction mixture was stirred at 80 °C forovernight. After cooling, the reaction was filtered, and the filter cakewas rinsed with tetrahydrofuran (3×). The solution was combinedand concentrated, and the residue was purified by preparative thin-layer chromatography (5:2 petroleum ether/tetrahydrofuran) to give4-(2,4-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4l(200 mg, 0.58 mmol, 58% yield) as a yellow solid. LC-MS (ES API)M + H = 342.



7035


4-(2,4-Dichlorobenzylamino)-2-methylquinoline-8-carboxa-mide (1s).

To a solution of 4-(2,4-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4l (200 mg, 0.58 mmol) in dimethyl sulfoxide (5 mL) wasadded solid potassium hydroxide (98 mg, 1.75 mmol) at roomtemperature. The reaction mixture was stirred at room temperature for2 min, at which time 30% hydrogen peroxide (3 mL) was addeddropwise over 2 min. The resulting mixture was stirred at roomtemperature for 30 min, and water (50 mL) was then added. Theprecipitate was collected, washed with water, and dried under avacuum to give a white solid. The solid was purified by reverse-phase high-performance liquid chromatography, eluting withacetonitrile/water with 0.5% trifluoroacetic acid (5:95 to 95:5) togive 4-(2,4-dichlorobenzylamino)-2-methylquinoline-8-carboxa-mide trifluoroacetate 1s (22 mg, 0.046 mmol, 8% yield) as awhite solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.08 (br d, 1H,J = 4 Hz), 8.51 (d, 1H, J = 7 Hz), 8.46 (d, 1H, J = 8 Hz), 8.23(br s, 1H), 8.03 (br t, 1H, J = 5 Hz), 7.76−7.65 (m, 2H), 7.52 (t,1H, J = 8 Hz), 7.42−7.36 (dd, 1H, J = 8, 2 Hz), 7.31 (d, 1H, J =8 Hz), 6.32 (s, 1H), 4.60 (d, 2H, J = 5 Hz), 2.46 (s, 3H); HRMS:C18H15Cl2N3O requires M + H at m/z 360.0670; found, 360.0669;tR = 1.91 min, 100.0% purity.8-Bromo-N-(2,5-dimethylbenzyl)-2-methylquinolin-4-amine (3i).

(2,5-Dimethylphenyl)methanamine (283 mg, 2.096 mmol) was addedto a solution of 8-bromo-4-chloro-2-methylquinoline 2a (512 mg,1.996 mmol) in N,N-dimethylacetamide (10 mL) under nitrogen atroom temperature. Then, potassium carbonate (414 mg, 2.99 mmol)was added, and the resulting mixture was heated in a microwave at160 °C for 5 h. After cooling, the reaction mixture was concentrated.Then, ethanol (4 mL) was added, and after stirring, the solid wascollected by filtration to give 8-bromo-N-(2,5-dimethylbenzyl)-2-methylquinolin-4-amine 3i (150 mg, 0.422 mmol, 21% yield) as awhite solid. LC-MS (ES API) M + H = 355.4-(2,5-Dimethylbenzylamino)-2-methylquinoline-8-carboni-

trile (4m).

Copper(I) cyanide (76 mg, 0.844 mmol) was added to 8-bromo-N-(2,5-dimethylbenzyl)-2-methylquinolin-4-amine 3i (150 mg,0.422 mmol) in N,N-dimethylacetamide (5 mL), and the reactionmixture was heated in a microwave at 160 °C for 5 h. After cooling,the reaction mixture was concentrated. The residue was purifiedby preparative thin-layer chromatography (petroleum ether) to give

4-(2,5-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4m(85 mg, 0.282 mmol, 67% yield). LC-MS (ES API) M + H = 302.

4-(2,5-Dimethylbenzylamino)-2-methylquinoline-8-carboxa-mide (1t).

Sodium hydroxide (47.8 mg, 1.194 mmol) was added to 4-(2,5-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4m (120 mg,0.398 mmol) in dimethyl sulfoxide (30 mL). Then, 30% hydrogenperoxide (5 mL) was added dropwise, and the reaction mixture wasstirred overnight. The reaction was diluted with water, and theresulting solid was collected by filtration to give 4-(2,5-dimethylben-zylamino)-2-methylquinoline-8-carboxamide 1t (55 mg, 0.172 mmol,43% yield) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ11.16 (br d, 1H, J = 5 Hz), 8.49 (d, 1H, J = 7 Hz), 8.48 (s, 1H), 7.85(br t, 1H, J = 5 Hz), 7.69 (br d, 1H, J = 5 Hz), 7.47 (t, 1H, J = 8 Hz),7.09 (d, 1H, J = 8 Hz), 7.00 (s, 1H), 6.97 (d, 1H, J = 8 Hz), 6.34 (s,1H), 4.47 (d, 2H, J = 5 Hz), 2.45 (s, 3H), 2.31 (s, 3H), 2.17 (s, 3H);HRMS: C20H21N3O requires M + H at m/z 320.1763; found,320.1764; tR = 1.16 min, 98.2% purity.

4-(2,5-Dichlorobenzylamino)-2-methylquinoline-8-carboni-trile (4n).

A solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (300 mg, 0.95 mmol) and (2,5-dichlorophenyl)methanamine(167 mg, 0.95 mmol) in dimethyl sulfoxide (5 mL) was stirredunder nitrogen at 90 °C for 24 h. The solution was cooled, pouredinto water, and extracted with ethyl acetate. The organics were washedwith brine, concentrated, and purified by preparative thin-layerchromatography (2:1 petroleum ether/ethyl acetate) to afford4-(2,5-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4n(150 mg, 0.44 mmol, 46% yield) as a white solid. LC-MS (ES API)M + H = 342.

2-Methyl-4-(2-methylbenzylamino)quinoline-8-carboxa-mide (1u).

30% Hydrogen peroxide (0.25 mL, 8.18 mmol) was added dropwiseto a mixture of 4-(2,5-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4n (140 mg, 0.41 mmol) and sodium hydroxide (65.4 mg,1.64 mmol) in dimethyl sulfoxide (5 mL). The reaction mixture wasthen stirred at room temperature overnight. The reaction mixture waspoured into water and filtered to give 4-(2,5-dichlorobenzylamino)-2-methylquinoline-8-carboxamide 1u (58 mg, 0.15 mmol, 37% yield)as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.07 (d, 1H,J = 4 Hz), 8.52 (d, 1H, J = 7 Hz), 8.45 (d, 1H, J = 8 Hz),



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8.00 (t, 1H, J = 6 Hz), 7.71 (d, 1H, J = 4 Hz), 7.60−7.49 (m, 2H), 7.41(dd, 1H, J = 8, 2 Hz), 7.35 (d, 1H, J = 2 Hz), 6.36 (s, 1H), 4.61 (d,2H, J = 6 Hz), 2.48 (s, 3H); HRMS: C18H15Cl2N3O requires M + H atm/z 360.0670; found, 360.0669; tR = 1.88 min, 95.0% purity.4-(2,6-Dichlorobenzylamino)-2-methylquinoline-8-carboni-

trile (4o).

To a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesul-fonate 7 (0.3 g, 0.95 mmol) in tetrahydrofuran (10 mL), was added1-(2,6-dichlorophenyl)methanamine (0.50 g, 2.85 mmol). The reactionmixture was stirred at 80 °C for 2 h. After cooling, water (20 mL) wasadded, and the precipitate was filtered to give 4-(2,6-dichlorobenzy-lamino)-2-methylquinoline-8-carbonitrile 4o (0.25 g, 0.67 mmol, 71%yield) as a pale solid. LC-MS (ES API) M + H = 342.4-(2,6-Dichlorobenzylamino)-2-methylquinoline-8-carboxa-

mide (1v).

To a solution of 4-(2,6-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4o (0.25 g, 0.73 mmol) in dimethyl sulfoxide (10 mL)was added sodium hydroxide (58 mg, 1.46 mmol), followed by 30%hydrogen peroxide (2.48 g, 73.1 mmol), which was added dropwise.The reaction mixture was stirred at room temperature overnight.Water (20 mL) was added, and the resulting precipitate was collectedvia filtration. 100 mg of crude product was obtained, which wascombined with another experiment. The solid was recrystallized fromdimethyl sulfoxide and water to give 4-(2,6-dichlorobenzylamino)-2-methylquinoline-8-carboxamide 1v (55 mg, 0.15 mmol, 21% yield) asa white solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.15 (br d, 1H,J = 5 Hz), 8.52−8.46 (m, 2H), 7.69 (br d, 1H, J = 5 Hz), 7.56 (d, 2H,J = 8 Hz), 7.48−7.37 (m, 3H), 6.67 (s, 1H), 4.64 (d, 2H, J = 4 Hz),2.57 (s, 3H); HRMS: C18H15Cl2N3O requires M + H at m/z360.0670; found, 360.0660; tR = 1.88 min, 98.5% purity.4-(3,4-Dimethylbenzylamino)-2-methylquinoline-8-carboni-

trile (4p).

(3,4-Dimethylphenyl)methanamine (270 mg, 1.998 mmol) was addedto 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg,0.999 mmol) in tetrahydrofuran (10 mL) under nitrogen. Then,potassium carbonate (276 mg, 1.998 mmol) was added, and the reactionmixture was heated at 75 °C overnight. The reaction mixture wasdiluted with water and extracted with ethyl acetate (3×). The combinedextracts were dried over sodium sulfate, filtered, and concentrated togive 4-(3,4-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4p

(245 mg, 0.813 mmol, 81% yield) as a white solid. LC-MS (ES API)M + H = 302.

4-(3,4-Dimethylbenzylamino)-2-methylquinoline-8-carboxa-mide (1w).

Sodium hydroxide (130 mg, 3.25 mmol) was added to 4-(3,4-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4p (245 mg,0.813 mmol) in dimethyl sulfoxide (3 mL) under nitrogen at roomtemperature. Then, 30% hydrogen peroxide (4 mL, 131 mmol) wasadded dropwise, and the reaction mixture was stirred at room temp for1 h. The reaction mixture was diluted with water and filtered to obtaina solid. The solid was further purified by preparative high-performanceliquid chromatography, eluting with acetonitrile/0.01 M ammoniumbicarbonate in water (5:95 to 95:5) to give 4-(3,4-dimethylbenzyla-mino)-2-methylquinoline-8-carboxamide 1w (50 mg, 0.157 mmol,19% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.14 (br d, 1H, J =4 Hz), 8.48 (d, 1H, J = 7 Hz), 8.44 (d, 1H, J = 9 Hz), 8.03 (br t, 1H,6 Hz), 7.68 (br d, 1H, J = 4 Hz), 7.47 (t, 1H, J = 7 Hz), 7.15 (s, 1H),7.98 (s, 2H), 6.36 (s, 1H), 4.48 (d, 2H, J = 6 Hz), 2.43 (s, 3H), 2.18 (s,3H), 2.17 (s, 3H); HRMS: C20H21N3O requires M + H at m/z320.1763; found, 320.1766; tR = 1.66 min, 100.0% purity.

4-(3,4-Dichlorobenzylamino)-2-methylquinoline-8-carboni-trile (4q).

Potassium carbonate (415 mg, 3.00 mmol) was added to a solution of8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg,1.000 mmol) in tetrahydrofuran (30 mL) at room temperature.Then, (3,4-dichlorophenyl)methanamine (528 mg, 3.00 mmol) wasadded dropwise over 1 min. The reaction mixture was heated at 80 °Covernight. The reaction mixture was diluted with water (50 mL) andfiltered, and the filtrate was purified by preparative thin-layerchromatography (1:1 petroleum ether/tetrahydrofuran) to obtain4-(3,4-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4q(129 mg, 0.297 mmol, 30% yield) as a white solid. LC-MS (ESAPI) M + H = 342.

4-(3,4-Dichlorobenzylamino)-2-methylquinoline-8-carboxa-mide Hydrochloride (1x).

Sodium hydroxide (60.3 mg, 1.508 mmol) was added to a solution of4-(3,4-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4q(129 mg, 0.377 mmol) in dimethyl sulfoxide (25 mL) under nitrogen



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at room temperature. Then, 30% hydrogen peroxide (2 mL,65.3 mmol) was added dropwise over 5 min. The reaction mixturewas stirred overnight. The reaction mixture was diluted with water(50 mL) and filtered, and the filtrate washed with water (2×). Thefiltrate was purified by reverse-phase high-performance liquidchromatography, eluting with acetonitrile/water with 0.1% hydro-chloric acid (30:70 to 65:35) to give 4-(3,4-dichlorobenzylamino)-2-methylquinoline-8-carboxamide hydrochloride 1x (82 mg, 0.225mmol, 60% yield) as a white solid. 1H NMR (400 MHz, CD3SOCD3):δ 14.25 (br s, 1H), 10.20 (br s, 1H), 8.91 (br s, 1H), 8.86 (s, 1H), 8.51(d, 1H, J = 6 Hz), 8.28 (s, 1H), 7.80−7.70 (m, 2H), 7.62 (d, 1H, J =6 Hz), 7.46 (d, 1H, J = 6 Hz), 6.86 (s, 1H), 4.78 (s, 2H), 2.44 (s, 3H);HRMS: C18H15Cl2N3O requires M + H at m/z 360.0670; found,360.0668; tR = 1.69 min, 98.9% purity.8-Bromo-N-(3,5-dimethylbenzyl)-2-methylquinolin-4-amine (3j).

(3,5-Dimethylphenyl)methanamine (135 mg, 0.998 mmol) was addedto a solution of 8-bromo-4-chloro-2-methylquinoline 2a (256 mg,0.998 mmol) in N,N-dimethylacetamide (3 mL) under nitrogen atroom temperature. Then, potassium carbonate (414 mg, 2.99 mmol)was added, and the resulting mixture was heated in a microwave at150 °C for 1 h. After cooling, the reaction mixture was concentrated.The residue was purified by thin-layer chromatography (2:1 petroleumether/ethyl acetate) to give 8-bromo-N-(3,5-dimethylbenzyl)-2-meth-ylquinolin-4-amine 3j (120 mg, 0.338 mmol, 34% yield). LC-MS (ESAPI) M + H = 355.4-(3,5-Dimethylbenzylamino)-2-methylquinoline-8-carboni-

trile (4r).

Copper(I) cyanide (91 mg, 1.013 mmol) was added to 8-bromo-N-(3,5-dimethylbenzyl)-2-methylquinolin-4-amine 3j (120 mg,0.338 mmol) in N,N-dimethylacetamide (2 mL), and the reactionmixture was heated in a microwave at 150 °C for 1 h. After cooling, thereaction mixture was filtered, and the solution was concentrated. Theresidue was purified by preparative thin-layer chromatography (1:1petroleum ether/ethyl acetate) to give 4-(3,5-dimethylbenzylamino)-2-methylquinoline-8-carbonitrile 4r (100 mg, 0.332 mmol, 98% yield)as a yellow solid. LC-MS (ES API) M + H = 302.4-(3,5-Dimethylbenzylamino)-2-methylquinoline-8-carboxa-

mide (1y).

Potassium hydroxide (93 mg, 1.659 mmol) in water (5.0 mL) wasadded to a solution of 4-(3,5-dimethylbenzylamino)-2-methylquino-line-8-carbonitrile 4r (100 mg, 0.332 mmol) in dimethyl sulfoxide(5 mL) under nitrogen at 0 °C. Then, 30% hydrogen peroxide (135 mg)

was added, and the reaction was stirred overnight. Water (10 mL) wasadded, and the resulting precipitate was collected by filtration, washedwith water (2×), and concentrated to give 4-(3,5-dimethylbenzylami-no)-2-methylquinoline-8-carboxamide 1y (45 mg, 0.137 mmol, 41%yield) as a yellow solid. 1H NMR (400 MHz, CDCl3): δ 11.80 (s, 1H),8.74 (d, 1H, J = 8 Hz), 7.86 (d, 1H, J = 8 Hz), 7.44 (t, 1H, J = 8 Hz),7.02−6.96 (m, 3H), 6.40 (s, 1H), 6.03 (s, 1H), 5.27 (br s, 1H), 4.41(d, 2H, J = 5 Hz), 2.59 (s, 3H), 2.32 (s, 6H); HRMS: C20H21N3Orequires M + H at m/z 320.1763; found, 320.1757; tR = 1.69 min,98.5% purity.

4-(3,5-Dichlorobenzylamino)-2-methylquinoline-8-carboni-trile (4s).

(3,5-Dichlorophenyl)methanamine (350 mg, 1.988 mmol) was addedto 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg,0.999 mmol) in tetrahydrofuran (5 mL), and the reaction mixture washeated at 75 °C overnight. The reaction mixture was filtered and con-centrated. The residue was purified by preparative thin-layer chromatog-raphy (5:2 petroleum ether/tetrahydrofuran) to give 4-(3,5-dichloroben-zylamino)-2-methylquinoline-8-carbonitrile 4s (306 mg, 0.152 mmol,15% yield) as a yellow solid. LC-MS (ES API) M + H = 342.

4-(3,5-Dichlorobenzylamino)-2-methylquinoline-8-carboxa-mide (1z).

Sodium hydroxide (220 mg, 5.50 mmol) was added to a solution of4-(3,5-dichlorobenzylamino)-2-methylquinoline-8-carbonitrile 4s(306 mg, 0.894 mmol) in dimethyl sulfoxide (15 mL) at room tem-perature. Then, 30% hydrogen peroxide (3 mL, 29.4 mmol) was added,and the mixture was stirred for 2 h. Water (20 mL) was added, and themixture was filtered. The residue was washed with water. Then, the crudeproduct was purified by reverse-phase high-performance liquid chromatog-raphy, eluting with acetonitrile/water with 0.5% trifluoroacetic acid (5:95to 95:5) to give 4-(3,5-dichlorobenzylamino)-2-methylquinoline-8-carbox-amide trifluoroacetate 1z (25 mg, 0.069 mmol, 8% yield) as a white solid.1H NMR (400 MHz, CD3OD): δ 8.62 (d, 1H, J = 7 Hz), 8.50 (d, 1H, J =6 Hz), 7.82 (t, 1H, J = 7 Hz), 7.44 (s, 3H), 6.79 (s, 1H), 4.85 (s, 2H), 2.73(s, 3H); HRMS: C18H15Cl2N3O requires M + H at m/z 360.0670; found,360.0669; tR = 1.39 min, 100.0% purity.

4-(3-Chloro-2-fluorobenzylamino)-2-methylquinoline-8-car-bonitrile (4t).

(3-Chloro-2-fluorophenyl)methanamine (303 mg, 1.9 mmol) wasadded to a solution of 8-cyano-2-methylquinolin-4-yl trifluorometha-nesulfonate 7 (300 mg, 0.949 mmol) in tetrahydrofuran (8 mL), and



7038


the reaction mixture was heated under nitrogen at 80 °C overnight.After cooling, water (20 mL) was added, leading to the formation of aprecipitate. The solids were collected by filtration, washed with water,and concentrated to give 4-(3-chloro-2-fluorobenzylamino)-2-methyl-quinoline-8-carbonitrile 4t (200 mg, 0.614 mmol, 65% yield) as ayellow solid. LC-MS (ES API) M + H = 326.4-(3-Chloro-2-fluorobenzylamino)-2-methylquinoline-8-car-

boxamide (1aa).

Potassium hydroxide (68.9 mg, 1.228 mmol) in water (2 mL) wasadded dropwise to a solution of 4-(3-chloro-2-fluorobenzylamino)-2-methylquinoline-8-carbonitrile 4t (200 mg, 0.614 mmol) in dimethylsulfoxide (5 mL) at room temperature. Then, 30% hydrogen peroxide(4.5 mL, 147 mmol) was added, and the reaction mixture was stirredovernight. The reaction mixture was diluted with water (15 mL),leading to the formation of a slurry. The precipitates were collected byfiltration and purified by preparative high-performance liquidchromatography, eluting with acetonitrile/water with 0.5% trifluoro-acetic acid (5:95 to 95:5) to give 4-(3-chloro-2-fluorobenzylamino)-2-methylquinoline-8-carboxamide trifluoroacetate 1aa (92 mg, 0.201mmol, 33% yield). 1H NMR (400 MHz, CD3SOCD3): δ 14.30 (br s,1H), 9.89 (br s, 1H), 8.88 (br s, 1H), 8.82 (d, 1H, J = 8 Hz), 8.52 (d,1H, J = 7 Hz), 8.29 (br s, 1H), 7.79 (t, 1H, J = 8 Hz), 7.56 (t, 1H, J = 7Hz), 7.37 (t, 1H, J = 7 Hz), 7.20 (t, 1H, J = 8 Hz), 6.91 (s, 1H), 4.87(d, 2H, J = 5 Hz), 2.66 (s, 3H). HRMS: C18H15ClFN3O requires M + Hat m/z 344.0966; found, 344.0959; tR = 1.82 min, 100.0% purity.4-(3-Chloro-2-methylbenzylamino)-2-methylquinoline-8-

carbonitrile (4u).

To a flask was added 8-cyano-2-methylquinolin-4-yl trifluoromethane-sulfonate 7 (316 mg, 1 mmol), (3-chloro-2-methylphenyl)methanamine(202 mg, 1.30 mmol), and potassium carbonate (276 mg, 2.0 mmol) intetrahydrofuran (5 mL) under nitrogen. The mixture was heated at 80 °Covernight, and then water (10 mL) was added to it. The solid thatprecipitated was collected via filtration to give 4-(3-chloro-2-methylbenzy-lamino)-2-methylquinoline-8-carbonitrile 4u (100 mg, 0.25 mmol, 25%yield). LC-MS (ES API) M + H = 322.4-(3-Chloro-2-methylbenzylamino)-2-methylquinoline-8-

carboxamide (1ab).

4-(3-Chloro-2-methylbenzylamino)-2-methylquinoline-8-carbonitrile4u (100 mg, 0.31 mmol) was dissolved in dimethyl sulfoxide (5 mL),and sodium hydroxide (24.9 mg, 0.62 mmol) was added, followedby 30% hydrogen peroxide (2.64 mL, 31.1 mmol). The resulting

homogeneous mixture was allowed to stir overnight. Then, water (20 mL)was added, and the resulting solid was collected by filtration to give 4-(3-chloro-2-methylbenzylamino)-2-methylquinoline-8-carboxamide 1ab (50 mg,0.15 mmol, 47% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.13 (brd, 1H, J = 4 Hz), 8.50 (d, 1H, J = 7 Hz), 8.48 (d, 1H, J = 8 Hz), 7.91 (brt, 1H, J = 5 Hz), 7.68 (br d, 1H, J = 4 Hz), 7.49 (t, 1H, J = 8 Hz), 7.36(dd, 1H, J = 8, 2 Hz), 7.20−7.10 (m, 2H), 6.36 (s, 1H), 4.57 (d, 2H, J =5 Hz), 2.46 (s, 3H), 2.42 (s, 3H); HRMS: C19H18ClN3O requires M + Hat m/z 340.1216; found, 340.1212; tR = 1.24 min, 100.0% purity.

4-(2-Fluoro-3-(trifluoromethyl)benzylamino)-2-methylqui-noline-8-carbonitrile (4v).

To a solution of potassium carbonate (0.262 g, 1.90 mmol) and8-cyano-2-methyl-4-quinolinyl trifluoromethanesulfonate 7 (0.3 g,0.95 mmol) in tetrahydrofuran (10 mL) was added {[2-fluoro-3-(trifluoromethyl)phenyl]methyl}amine (0.366 g, 1.90 mmol). Thereaction mixture was stirred at 82 °C overnight. After cooling, waterwas added (30 mL), and the resulting precipitate was filtered to give4-(2-fluoro-3-(trifluoromethyl)benzylamino)-2-methylquinoline-8-car-bonitrile 4v (0.4 g, 0.74 mmol, 77% yield) as a red solid. LC-MS (ESAPI) M + H = 360.

4-(2-Fluoro-3-(trifluoromethyl)benzylamino)-2-methylqui-noline-8-carboxamide (1ac).

To a solution of 4-(2-fluoro-3-(trifluoromethyl)benzylamino)-2-methylquinoline-8-carbonitrile 4v (0.4 g, 1.11 mmol) and potassiumhydroxide (0.250 g, 4.45 mmol) in dimethyl sulfoxide (8 mL) wasadded 30% hydrogen peroxide (3.41 mL, 111 mmol) dropwise. Thereaction mixture was stirred at room temperature overnight, at whichtime water (10 mL) was added. The resulting precipitate was filteredand further purified via reverse-phase liquid chromatography, elutingwith acetonitrile/water containing 0.05% trifluoroacetic acid (1:9 to1:1) to give 4-(2-fluoro-3-(trifluoromethyl)benzylamino)-2-methylqui-noline-8-carboxamide 1ac (0.125 g, 0.33 mmol, 30% yield) as a whitesolid. 1H NMR (400 MHz, CD3OD): δ 8.60 (d, 1H, J = 9 Hz), 8.48(d, 1H, J = 7 Hz), 7.78 (t, 1H, J = 8 Hz), 7.74−7.66 (m, 2H), 7.37 (t,1H, J = 8 Hz), 6.87 (s, 1H), 4.95 (s, 2H), 2.72 (s, 3H); HRMS:C19H15F4N3O requires M + H at m/z 378.1229; found, 378.1224; tR =1.41 min, 100.0% purity.

2-Methyl-4-(naphthalen-1-ylmethylamino)quinoline-8-car-bonitrile (4w).



7039


Naphthalen-1-ylmethanamine (314 mg, 1.998 mmol) was added to8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate 7 (316 mg,0.999 mmol) in tetrahydrofuran (10 mL) under nitrogen. Then,potassium carbonate (276 mg, 1.998 mmol) was added, and thereaction mixture was heated at 80 °C overnight. Then, the reactionmixture was diluted with water, and the resulting precipitate wascollected by filtration to give 2-methyl-4-(naphthalen-1-ylmethylamino)-quinoline-8-carbonitrile 4w (180 mg, 0.557 mmol, 56% yield). LC-MS(ES API) M + H = 324.2-Methyl-4-(naphthalen-1-ylmethylamino)quinoline-8-car-

boxamide (1ad).

Potassium hydroxide (1.026 g, 7.42 mmol) was added to 2-methyl-4-(naphthalen-1-ylmethylamino)quinoline-8-carbonitrile 4w (120 mg,0.371 mmol) in dimethyl sulfoxide (5 mL) at room temperature.Then, 30% hydrogen peroxide (4.28 mL, 41.9 mmol) was addeddropwise over 15 min. The reaction mixture was stirred overnight.The reaction mixture was diluted with water, and the resultingprecipitate was collected by filtration to give 2-methyl-4-(naphthalen-1-ylmethylamino)quinoline-8-carboxamide 1ad (60 mg, 0.176 mmol,47% yield). 1H NMR (400 MHz, CD3OD): δ 11.14 (br d, 1H, J =4 Hz), 8.54−8.50 (m, 2H), 8.23 (d, 1H, J = 8 Hz), 8.06 (br t, 1H, J =5 Hz), 7.98 (d, 1H, J = 8 Hz), 7.86 (d, 1H, J = 6 Hz), 7.67 (d, 1H, J =4 Hz), 7.64−7.56 (m, 2H), 7.54−7.44 (m, 3H), 6.45 (s, 1H), 5.04 (d,2H, J = 5 Hz), 2.43 (s, 3H); HRMS: C22H19N3O requires M + H atm/z 342.1606; found, 342.1597; tR = 1.66 min, 99.2% purity.4-(2,6-Difluorobenzylamino)-2-methylquinoline-8-carboni-

trile (4x).

A mixture of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (316 mg, 1.0 mmol) and (2,6-difluorophenyl)methanamine (280 mg,1.96 mmol) in tetrahydrofuran (5 mL) was stirred at 75 °C overnight.The mixture was filtered, and the solvent was evaporated under reducedpressure. The residue was purified by preparative thin-layerchromatography (5:2 petroleum ether/tetrahydrofuran) to give4-(2,6-difluorobenzylamino)-2-methylquinoline-8-carbonitrile 4x(160 mg, 0.52 mmol, 23% yield) as a yellow solid. LC-MS (ESAPI) M + H = 310.4-(2-Chloro-3,6-difluorobenzylamino)-2-methylquinoline-8-

carboxamide (1ae).

To a solution of 4-(2,6-difluorobenzylamino)-2-methylquinoline-8-carbonitrile 4x (160 mg, 0.52 mmol) in dimethyl sulfoxide (15 mL)was added sodium hydroxide (210 mg, 5.25 mmol) at room tem-perature. Then, 30% hydrogen peroxide (3 mL, 29.4 mmol) was added

after 15 min. The mixture was stirred for 2 h, at which time water(20 mL) was added and the mixture was filtered. The residue waswashed with water, and the crude product was purified by reverse-phase high-performance liquid chromatography, eluting with acetoni-trile/water with 0.05% trifluoroacetic acid to give 4-(2-chloro-3,6-difluorobenzylamino)-2-methylquinoline-8-carboxamide trifluoroace-tate 1ae (20 mg, 0.061 mmol, 12% yield) as a white solid. 1H NMR(400 MHz, CD3SOCD3): δ 14.34 (br s, 1H), 9.43 (br s, 1H), 8.83 (brs, 1H), 8.72 (d, 1H, J = 7 Hz), 8.49 (d, 1H, J = 7 Hz), 8.30 (br s, 1H),7.77 (br s, 1H), 7.60−7.46 (m, 1H), 7.21 (t, 2H, J = 8 Hz), 7.02 (br s,1H), 4.80 (br s, 2H), 2.73 (s, 3H); HRMS: C18H15F2N3O requiresM + H at m/z 328.1261; found, 328.1258; tR = 1.20 min, 100.0% purity.

4-(2-Chloro-6-fluorobenzylamino)-2-methylquinoline-8-car-bonitrile (4y).

To a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesul-fonate 7 (316 mg, 1.0 mmol) in dimethyl sulfoxide (10 mL) stirredunder nitrogen at room temperature was added neat (2-chloro-6-fluorophenyl)methanamine (798 mg, 5.0 mmol) dropwise during1 min. The reaction mixture was stirred at 80 °C overnight. Thereaction mixture was partitioned between water (50 mL) and filtered,and the filtrate washed with water twice. The filtrate was dried in vacuoto obtain 4-(2-chloro-6-fluorobenzylamino)-2-methylquinoline-8-car-bonitrile 4y (195 mg, 0.54 mmol, 54% yield) as a white solid. LC-MS(ES API) M + H = 326.

4-(2-Chloro-6-fluorobenzylamino)-2-methylquinoline-8-car-boxamide (1af).

To a solution of 4-(2-chloro-6-fluorobenzylamino)-2-methylquinoline-8-carbonitrile 4y (195 mg, 0.60 mmol) and sodium hydroxide (96 mg,2.39 mmol) in dimethyl sulfoxide (20 mL) under nitrogen at 0 °C wasadded 30% hydrogen peroxide (5 mL, 163 mmol) dropwise during5 min. The reaction mixture was stirred at room temperatureovernight. Water (50 mL) was added to the mixture, followed byfiltration. The filtrate was washed with water twice and then dried invacuo to obtain 4-(2-chloro-6-fluorobenzylamino)-2-methylquinoline-8-carboxamide 1af (165 mg, 0.46 mmol, 77% yield) as a white solid.1H NMR (CDCl3): δ 11.70 (br s, 1H), 8.66 (dd, 1H, J = 8, 1 Hz), 7.78(d, 1H, J = 9 Hz), 7.37 (t, 1H, J = 8 Hz), 7.26−7.14 (m, 2H), 7.01 (dt,1H, J = 8, 2 Hz), 6.56 (s, 1H), 6.01 (br s, 1H), 5.43 (br s, 1H), 4.63 (d,2H, J = 5 Hz), 2.56 (s, 3H); HRMS: C18H15ClFN3O requires M + Hat m/z 344.0966; found, 344.0963; tR = 1.63 min, 95.6% purity.

4-(2-Chloro-6-methylbenzylamino)-2-methylquinoline-8-carbonitrile (4z).



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A solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfonate7 (335 mg, 1.06 mmol), (2-chloro-6-methylphenyl)methanamine(150 mg, 0.96 mmol), and potassium carbonate (266 mg, 1.93 mmol) intetrahydrofuran (5 mL) was stirred under nitrogen at 80 °C overnight.Water (15 mL) was added, and the organics were extracted withtetrahydrofuran (2×). The solution was concentrated in vacuo to give4-(2-chloro-6-methylbenzylamino)-2-methylquinoline-8-carbonitrile 4z(90 mg, 0.28 mmol, 29% yield). LC-MS (ES API) M + H = 322.4-(2-Chloro-6-methylbenzylamino)-2-methylquinoline-8-

carboxamide (1ag).

To a solution of 4-(2-chloro-6-methylbenzylamino)-2-methylquino-line-8-carbonitrile 4z (90 mg, 0.28 mmol) and sodium hydroxide(55.9 mg, 1.40 mmol) in dimethyl sulfoxide (15 mL) at 25 °C was added30% hydrogen peroxide (2 mL, 65.3 mmol) dropwise over 5 min. Thereaction mixture was stirred at 25 °C overnight. Water was added to thereaction, and the resulting solid was collected via filtration. The solid waspurified by reverse-phase high-performance liquid chromatography,eluting with acetonitrile/water with 0.05% trifluoroacetic acid (5:95 to95:5) to give 4-(2-chloro-6-methylbenzylamino)-2-methylquinoline-8-carboxamide trifluoroacetate 1ag (35 mg, 0.10 mmol, 37% yield).1H NMR (400 MHz, CD3SOCD3): δ 11.15 (br s, 1H), 8.50 (dd, 1H, J =7, 1 Hz), 8.48 (dd, 1H, J = 8, 2 Hz), 8.16 (br s, 1H), 7.70 (d, 1H, J =4 Hz), 7.41 (t, 1H, J = 8 Hz), 7.37 (d, 1H, J = 8 Hz), 7.33 (br s, 1H), 7.29(t, 1H, J = 8 Hz), 7.27−7.22 (m, 1H), 6.66 (s, 1H), 4.54 (d, 2H, J =4 Hz), 2.57 (s, 3H), 2.40 (s, 3H); HRMS: C19H18ClN3O requires M + Hat m/z 340.1216; found, 340.1214; tR = 1.28 min, 94.6% purity.8-Bromo-N-(2-fluoro-6-(trifluoromethyl)benzyl)-2-methyl-

quinolin-4-amine (3j).

N,N-Diisopropylethylamine (1.034 mL, 5.94 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5076 g, 1.979 mmol) indimethyl sulfoxide (3.91 mL) at room temperature, followed by 2-fluoro-6-trifluoromethylbenzylamine (0.573 g, 2.97 mmol), and thesolution was heated at 140 °C and stirred for 66 h. The reaction mixturewas poured into ether, washed with water, dried over magnesium sulfate,filtered, and concentrated. The residue was purified by silica gelchromatography, eluting with ethyl acetate/hexanes (1:3) to give8-bromo-N-(2-fluoro-6-(trifluoromethyl)benzyl)-2-methylquinolin-4-amine 3j (0.2838 g, 0.652 mmol, 33% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.23 (d, 1H, J = 8 Hz), 7.93 (d, 1H, J = 7 Hz), 7.71−7.61(m, 3H), 7.24 (br t, 1H, J = 4 Hz), 7.19 (t, 1H, J = 8 Hz), 6.61 (s, 1H),4.50 (d, 2H, J = 3 Hz), 2.53 (s, 3H); LC-MS (LC-ES) M + H = 413.4-((2-Fluoro-6-(trifluoromethyl)benzyl)amino)-2-methylqui-

noline-8-carboxamide (1ah).

1,1′-Bis(diphenylphosphino)ferrocene (0.076 g, 0.137 mmol) andbis(trimethylsilyl)amine (2.173 mL, 10.30 mmol) were added to8-bromo-N-(2-fluoro-6-(trifluoromethyl)benzyl)-2-methylquinolin-4-amine 3j (0.2838 g, 0.687 mmol) in N,N-dimethylformamide(4.69 mL) at room temperature, followed by tris(dibenzylideneacetone)-dipalladium(0) (0.063 g, 0.069 mmol), and the solution was fitted witha carbon monoxide (1.924 g, 68.7 mmol) balloon, heated at 100 °C,and stirred for 4 h. The reaction mixture was cooled, poured intoether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (4:1)to give 4-((2-fluoro-6-(trifluoromethyl)benzyl)amino)-2-methylquino-line-8-carboxamide 1ah (0.0617 g, 0.155 mmol, 23% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.12 (br d, 1H, J = 5 Hz), 8.47 (d, 1H,J = 7 Hz), 8.42 (d, 1H, J = 8 Hz), 7.72−7.62 (m, 4H), 7.44−7.37 (m,2H), 6.64 (s, 1H), 4.52 (s, 2H), 2.56 (s, 3H); HRMS: C19H15F4N3Orequires M + H at m/z 378.1229; found, 378.1226; tR = 0.55 min,100.0% purity.

8-Bromo-2-methyl-N-[(2,3,6-trichlorophenyl)methyl]-4-qui-nolinamine (3k).

1-(2,3,6-Trichlorophenyl)methanamine hydrochloride (13.81 g,55.9 mmol) was added to 8-bromo-4-chloro-2-methylquinoline 2a(10.25 g, 10.25 mmol) in N-methyl-2-pyrrolidone (25 mL), and thereaction mixture was heated at 150 °C overnight. The mixture wasallowed to cool to room temperature, and the solid was filtered. Thecake was washed with small amount of N-methyl-2-pyrrolidone,followed by acetonitrile, and dried to obtain 8-bromo-2-methyl-N-[(2,3,6-trichlorophenyl)methyl]-4-quinolinamine hydrochloride(15 g) as an off-white solid. 8-Bromo-2-methyl-N-[(2,3,6-trichlorophenyl)methyl]-4-quinolinamine hydrochloride was mixedwith a 10% aqueous NaOH solution (250 mL), and the suspensionwas kept at 100 °C for 8 h. After cooling to room temperature, thesolid was filtered and washed with water until the last wash was neutralpH. The cake was then dried to obtain 8-bromo-2-methyl-N-[(2,3,6-trichlorophenyl)methyl]-4-quinolinamine 3k (13.2 g, 30.7 mmol, 77%yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.23 (d, 1H, J = 6 Hz),7.93 (d, 1H, J = 5 Hz), 7.71 (d, 1H, J = 8 Hz), 7.58 (d, 1H, J =8 Hz), 7.27 (s, 1H), 7.20 (s, 1H), 6.63 (s, 1H), 4.62 (s, 2H), 2.53(s, 3H).

2-Methyl-4-{[(2,3,6-trichlorophenyl)methyl]amino}-8-quino-linecarboxamide (1ai).

A stirred mixture of 8-bromo-2-methyl-N-[(2,3,6-trichlorophenyl)methyl]-4-quinolinamine 3k (9.5 g, 22.06 mmol), 1,1′-bis(diphenylphosphino)-ferrocene (1.22 g, 2.2 mmol), tris(dibenzylideneacetone)dipalladium(0)(1.01 g, 1.1 mmol), and bis(trimethylsilyl)amine (70 mL) in N,N-dimethylformamide (140 mL) was flushed with nitrogen and thencarbon dioxide at room temperature; then, the mixture was heated at100 °C while carbon monoxide was passing through the reaction. Themixture was stirred at 100 °C for 40 min under carbon monoxideblanket. The reaction mixture was cooled to room temperature, andwater (70 mL) was added to convert the trimethylsilyl amide to theprimary amide. After complete conversion, more water (1 L) was



7041


added, and the mixture was stirred at room temperature for 30 minand then filtered. The solid was dissolved in tetrahydrofuran (300 mL),and a scavenger resin (10 g of PL-BnSH MP-resin, 2.47 mol/g,Varian) was added. The mixture was stirred at room temperatureovernight. The resin was filtered and washed with tetrahydrofuran(50 mL, 2×). The filtrate was concentrated to 100 mL, cooled to−78 °C for 20 min, and filtered. The cake was dissolved in boilingethanol (400 mL). Ethanol (100 mL) was distilled out to remove anyresidual tetrahydrofuran, and the solution was cooled to −75 °C for 30 minand then filtered. The cake was washed with cold ethanol (10 mL) anddried in a vacuum oven at 100 °C overnight to obtain 2-methyl-4-{[(2,3,6-trichlorophenyl)methyl]amino}-8-quinolinecarboxamide 1ai(6.3 g, 15.96 mmol, 72% yield). 1H NMR (400 MHz, CD3SOCD3):δ 11.11 (d, 1H, J = 5 Hz), 8.46 (d, 1H, J = 7 Hz), 8.41 (d, 1H, J =9 Hz), 7.72 (d, 1H, J = 9 Hz), 7.71 (s, 1H), 7.59 (d, 1H, J = 9 Hz),7.40 (t, 1H, J = 8 Hz), 7.36 (m, 1H), 6.64 (s, 1H), 4.63 (d, 2H, J =4 Hz), 2.56 (s, 3H); HRMS: C18H14Cl3N3O requires M + H at m/z394.0280; found, 394.0274; tR = 2.01 min, 100.0% purity.4-{[(3-Chloro-2,6-difluorophenyl)methyl]amino}-2-methyl-8-

quinolinecarbonitrile (4aa).

To a solution of 8-cyano-2-methyl-4-quinolinyl trifluoromethanesul-fonate 7 (300 mg, 0.95 mmol) in tetrahydrofuran (4 mL) undernitrogen was added 1-(3-chloro-2,6-difluorophenyl)methanamine(337 mg, 1.90 mmol). The mixture was stirred at 80 °C for 24 h.After cooling, the reaction was taken up in ethyl acetate, followed bywashing with brine. The crude compound was added purified by silicagel chromatography, eluting with ethyl acetate/hexanes (1:2) to give4-{[(3-chloro2,6-difluorophenyl)methyl]amino}-2-methyl-8-quinoli-necarbonitrile 4aa (126 mg, 0.35 mmol, 37% yield) as a white solid.LC-MS (ES API) M + H = 344.4-{[(3-Chloro-2,6-difluorophenyl)methyl]amino}-2-methyl-8-

quinolinecarboxamide (1aj).

To a dimethyl sulfoxide solution (20 mL) containing 4-{[(3-chloro-2,6-difluorophenyl)methyl]amino}-2-methyl-8-quinolinecarbonitrile4aa (126 mg, 0.37 mmol) was added sodium hydroxide (44.0 mg,1.1 mmol), followed by slow addition of 30% hydrogen peroxide(249 mg, 7.33 mmol). The reaction mixture was stirred attemperature for 4 h. After cooling, water was added, and the solidwas filtered. The crude product was washed with water (3×) togive 4-{[(3-chloro-2,6-difluorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1aj (50 mg, 0.13 mmol, 37% yield) as awhite solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.11 (d, 1H,J = 5 Hz), 8.49 (dd, 1H, J = 8, 2 Hz), 8.40 (dd, 1H, J = 8, 2 Hz),7.72−7.62 (m, 3H), 7.46 (t, 1H, J = 8 Hz), 7.25 (dt, 1H, J =8, 2 Hz), 6.60 (s, 1H), 4.57 (d, 2H, J = 5 Hz), 2.55 (s, 3H);HRMS: C18H14ClF2N3O requires M + H at m/z 362.0871; found,362.0873; tR = 1.82 min, 97.3% purity.

4-(2-Chloro-3,6-difluorobenzylamino)-2-methylquinoline-8-carbonitrile (4ab).

To a solution of 8-cyano-2-methylquinolin-4-yl trifluoromethanesulfo-nate 7 (316 mg, 1.0 mmol) and (2-chloro-3,6-difluorophenyl)methanamine(266 mg, 1.5 mmol) in tetrahydrofuran (5 mL) under nitrogen at roomtemperature was added solid potassium carbonate (276 mg, 2.0 mmol).The reaction mixture was stirred at 80 °C overnight. After cooling, thereaction was filtered, and the filter cake was rinsed with tetrahydrofuran(3×). The solution was combined and concentrated, and the residue waspurified by thin-layer chromatography (5:2 petroleum ether/tetrahydrofur-an) to give 4-(2-chloro-3,6-difluorobenzylamino)-2-methylquinoline-8-carbonitrile 4ab (205 mg, 0.60 mmol, 60% yield) as a yellow solid.LC-MS (ES API) M + H = 344.

4-(2-Chloro-3,6-difluorobenzylamino)-2-methylquinoline-8-carboxamide (1ak).

To a solution of 4-(2-chloro-3,6-difluorobenzylamino)-2-methylquino-line-8-carbonitrile 4ab (205 mg, 0.60 mmol) in dimethyl sulfoxide(5 mL) was added solid potassium hydroxide (100 mg, 1.79 mmol).The reaction mixture was stirred at 25 °C for 2 min, and then 30%hydrogen peroxide (3 mL) was added dropwise during 2 min. Theresulting mixture was stirred at room temperature for 30 min. Water(50 mL) was added, and the precipitated solid was collected, washed withwater, and dried under vacuum to give 4-(2-chloro-3,6-difluorobenzyla-mino)-2-methylquinoline-8-carboxamide 1ak (48 mg, 0.13 mmol, 21%yield) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.11 (br s,1H), 8.49 (d, 1H, J = 7 Hz), 8.42 (d, 1H, J = 8 Hz), 7.71 (br s, 1H),7.64−7.48 (m, 2H), 7.48−7.34 (m, 2H), 6.63 (br s, 1H), 4.59 (br s, 2H),2.56 (s, 3H); HRMS: C18H14ClF2N3O requires M + H at m/z 362.0871;found, 362.0865; tR = 0.97 min, 95.4% purity.

8-Bromo-N-[(3,6-dichloro-2-fluorophenyl)methyl]-2-methyl-4-quinolinamine (3l).

Sodium hydride (60%, 0.095 g, 2.371 mmol) was added to 8-bromo-2-methyl-4-quinolinamine 3ae (0.5110 g, 2.155 mmol) in N,N-dimethylformamide (10.78 mL) and tetrahydrofuran (10.78 mL) at0 °C. Then, 2-(bromomethyl)-1,4-dichloro-3-fluorobenzene (0.667 g,2.59 mmol) was added, and the reaction mixture was stirred for 4 h atroom temperature. The reaction mixture was diluted with water andextracted with diethyl ether, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography, elutingwith ethyl acetate/hexanes (1:4) to give 8-bromo-N-[(3,6-dichloro-2-fluorophenyl)methyl]-2-methyl-4-quinolinamine 3l (0.1436 g, 0.329 mmol,15% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.20 (d, 1H, J = 5 Hz),



7042


7.94 (d, 1H, J = 7 Hz), 7.66 (t, 1H, J = 8 Hz), 7.45 (d, 1H, J = 9 Hz),7.37 (br t, 1H, J = 4 Hz), 7.22 (t, 1H, J = 8 Hz), 6.60 (s, 1H), 4.56 (d,2H, J = 4 Hz), 2.52 (s, 3H); LC-MS (LC-ES) M + H = 414.4-{[(3,6-Dichloro-2-fluorophenyl)methyl]amino}-2-methyl-8-

quinolinecarboxamide (1al).

N,N-Diisopropylethylamine (0.133 mL, 0.763 mmol) and hexame-thyldisilazane (0.509 mL, 2.427 mmol) were added to 8-bromo-N-[(3,6-dichloro-2-fluorophenyl)methyl]-2-methyl-4-quinolinamine 3l(0.1436 g, 0.347 mmol) in N,N-dimethylformamide (3.47 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.043 g, 0.104 mmol) and palladium(II) acetate (0.016 g, 0.069 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 4 h. The reaction mixture was cooled, pouredinto diethyl ether, washed with 1 N sodium hydroxide and water, driedover magnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with ethyl acetate/hexanes (4:1) to give 4-{[(3,6-dichloro-2-fluorophenyl)methyl]-amino}-2-methyl-8-quinolinecarboxamide 1al (0.0481 g, 0.121 mmol,35% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.10 (br d, 1H, J =5 Hz), 8.47 (d, 1H, J = 7 Hz), 8.39 (d, 1H, J = 8 Hz), 7.70 (br d, 1H,J = 5 Hz), 7.66 (t, 1H, J = 8 Hz), 7.52 (br t, 1H, J = 4 Hz), 7.45 (d, 1H,J = 9 Hz), 7.43 (t, 1H, J = 8 Hz), 6.63 (s, 1H), 4.58 (d, 2H, J = 4 Hz),2.55 (s, 3H); HRMS: C18H14Cl2FN3O requires M + H at m/z378.0576; found, 378.0573; tR = 0.60 min, 98.5% purity.8-Bromo-N-[(2,3-dichloro-6-fluorophenyl)methyl]-2-methyl-

4-quinolinamine (3m).

N,N-Diisopropylethylamine (1.036 mL, 5.93 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5072 g, 1.977 mmol) indimethyl sulfoxide (6.59 mL) at room temperature, followed by [(2,3-dichloro-6-fluorophenyl)methyl]amine (0.575 g, 2.97 mmol), and thesolution was heated at 150 °C and stirred for 112 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (3:7)to give 8-bromo-N-[(2,3-dichloro-6-fluorophenyl)methyl]-2-methyl-4-quinolinamine 3m (0.4665 g, 1.070 mmol, 54% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.21 (d, 1H, J = 8 Hz), 7.93 (d, 1H, J =8 Hz), 7.74 (dd, 1H, J = 9, 5 Hz), 7.39 (t, 1H, J = 9 Hz), 7.35 (br t,1H, J = 4 Hz), 7.21 (t, 1H, J = 8 Hz), 6.59 (s, 1H), 4.56 (d, 2H, J =3 Hz), 2.51 (s, 3H); LC-MS (LC-ES) M + H = 414.4-{[(2,3-Dichloro-6-fluorophenyl)methyl]amino}-2-methyl-8-

quinolinecarboxamide (1am).

N,N-Diisopropylethylamine (0.193 mL, 1.102 mmol) and hexame-thyldisilazane (0.735 mL, 3.51 mmol) were added to 8-bromo-N-[(2,3-dichloro-6-fluorophenyl)methyl]-2-methyl-4-quinolinamine 3m(0.2075 g, 0.501 mmol) in N,N-dimethylformamide (10.02 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.062 g, 0.150 mmol) and palladium(II) acetate (0.022 g, 0.100 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (4:1)to give 4-{[(2,3-dichloro-6-fluorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1am (0.0525 g, 0.132 mmol, 26% yield). 1HNMR (400 MHz, CD3SOCD3): δ 11.10 (br d, 1H, J = 5 Hz), 8.47 (d,1H, J = 8 Hz), 8.40 (d, 1H, J = 8 Hz), 7.74 (dd, 1H, J = 9, 5 Hz), 7.70(br d, 1H, J = 5 Hz), 7.51 (br t, 1H, J = 4 Hz), 7.43 (t, 1H, J = 8 Hz),7.40 (t, 1H, J = 9 Hz), 6.62 (s, 1H), 4.58 (d, 2H, J = 3 Hz), 2.55 (s,3H); LC-MS (LC-ES) M − H = 379. HRMS: C18H14Cl2FN3Orequires M + H at m/z 378.0576; found, 378.0572; tR = 0.66 min,100.0% purity.

8-Bromo-N-[(2-chloro-6-fluoro-3-methylphenyl)methyl]-2-methyl-4-quinolinamine (3n).

N,N-Diisopropylethylamine (1.056 mL, 6.05 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5172 g, 2.016 mmol) indimethyl sulfoxide (5.66 mL) at room temperature, followed by [(2-chloro-6-fluoro-3-methylphenyl)methyl]amine (0.525 g, 3.02 mmol),and the solution was heated at 150 °C and stirred for 16 h. Thereaction mixture was cooled, poured into ether, washed with water,dried over magnesium sulfate, filtered, and concentrated. The residuewas purified by silica gel chromatography, eluting with ethyl acetate/hexanes (3:7) to give 8-bromo-N-[(2-chloro-6-fluoro-3-methylphenyl)-methyl]-2-methyl-4-quinolinamine 3n (0.6887 g, 1.662 mmol, 82%yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.24 (d, 1H, J = 8 Hz),7.92 (d, 1H, J = 7 Hz), 7.41 (dd, 1H, J = 8, 7 Hz), 7.36 (br t, 1H, J =4 Hz), 7.24−7.16 (m, 2H), 6.59 (s, 1H), 4.53 (d, 2H, J = 4 Hz), 2.50(s, 3H), 2.33 (s, 3H); LC-MS (LC-ES) M + H = 393.

4-{[(2-Chloro-6-fluoro-3-methylphenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide (1an).

N,N-Diisopropylethylamine (0.152 mL, 0.871 mmol) and hexame-thyldisilazane (0.581 mL, 2.77 mmol) were added to 8-bromo-N-[(2-chloro-6-fluoro-3-methylphenyl)methyl]-2-methyl-4-quinolinamine 3n(0.1559 g, 0.396 mmol) in N,N-dimethylformamide (3.23 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.049 g, 0.119 mmol) and palladium(II) acetate (0.018 g, 0.079 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (4:1)to give 4-{[(2-chloro-6-fluoro-3-methylphenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1an (0.0477 g, 0.127 mmol, 32%yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.12 (br d, 1H,



7043


J = 5 Hz), 8.46 (d, 1H, J = 8 Hz), 8.44 (d, 1H, J = 9 Hz), 7.68 (br d,1H, J = 5 Hz), 7.52 (br t, 1H, J = 4 Hz), 7.46−7.38 (m, 2H), 7.21 (t,1H, J = 9 Hz), 6.62 (s, 1H), 4.55 (d, 2H, J = 4 Hz), 2.54 (s, 3H), 2.34(s, 3H); HRMS: C19H17ClFN3O requires M + H at m/z 358.1122;found, 358.1124; tR = 0.70 min, 96.0% purity.8-Bromo-2-methyl-N-{[3-(trifluoromethyl)-2-pyridinyl]-

methyl}-4-quinolinamine (3o).

N,N-Diisopropylethylamine (1.378 mL, 7.89 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5060 g, 1.973 mmol) indimethyl sulfoxide (6.58 mL) at room temperature, followed by {[3-(trifluoromethyl)-2-pyridinyl]methyl}amine (0.521 g, 2.96 mmol), andthe solution was heated at 150 °C and stirred for 88 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (2:3) togive 8-bromo-2-methyl-N-{[3-(trifluoromethyl)-2-pyridinyl]methyl}-4-quinolinamine 3o (0.3020 g, 0.671 mmol, 34% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.78 (d, 1H, J = 5 Hz), 8.23 (d, 1H, J =7 Hz), 8.21 (d, 1H, J = 8 Hz), 7.96 (d, 1H, J = 7 Hz), 7.78 (br t, 1H, J =5 Hz), 7.57 (dd, 1H, J = 8, 5 Hz), 7.28 (t, 1H, J = 8 Hz), 6.35 (s, 1H),4.77 (d, 2H, J = 5 Hz), 2.41 (s, 3H); LC-MS (LC-ES) M + H = 396.2-Methyl-4-({[3-(trifluoromethyl)-2-pyridinyl]methyl}-

amino)-8-quinolinecarboxamide (1ao).

N,N-Diisopropylethylamine (0.152 mL, 0.871 mmol) and hexame-thyldisilazane (0.581 mL, 2.77 mmol) were added to 8-bromo-2-methyl-N-{[3-(trifluoromethyl)-2-pyridinyl]methyl}-4-quinolinamine 3o(0.1569 g, 0.396 mmol) in N,N-dimethylformamide (7.92 mL) at roomtemperature, followed by 1,3-bis(diphenylphosphino)propane (0.049 g,0.119 mmol) and palladium(II) acetate (0.018 g, 0.079 mmol), and thesolution was fitted with a carbon monoxide balloon, heated at 110 °C,and stirred for 2 h. The reaction mixture was cooled, poured into ether,washed with 1 N sodium hydroxide and water, dried over magnesiumsulfate, filtered, and concentrated. The residue was purified by silica gelchromatography, eluting with methanol/ethyl acetate (1:99) to give2-methyl-4-({[3-(trifluoromethyl)-2-pyridinyl]methyl}amino)-8-quinoli-necarboxamide 1ao (0.0411 g, 0.108 mmol, 27% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.10 (br d, 1H, J = 5 Hz), 8.79 (d, 1H, J =5 Hz), 8.49 (d, 1H, J = 7 Hz), 8.40 (d, 1H, J = 8 Hz), 8.23 (d, 1H, J =8 Hz), 7.94 (br t, 1H, J = 4 Hz), 7.69 (br d, 1H, J = 4 Hz), 7.57 (dd, 1H,J = 8, 5 Hz), 7.49 (t, 1H, J = 8 Hz), 6.38 (s, 1H), 4.80 (d, 2H, J = 5 Hz),2.44 (s, 3H); HRMS: C18H15F3N4O requires M + H at m/z 361.1276;found, 361.1276; tR = 0.57 min, 96.7% purity.8-Bromo-2-methyl-N-{[4-(trifluoromethyl)-3-pyridinyl]-

methyl}-4-quinolinamine (3p).

N,N-Diisopropylethylamine (0.696 mL, 3.99 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5112 g, 1.993 mmol) indimethyl sulfoxide (6.64 mL) at room temperature, followed by {[4-(trifluoromethyl)-3-pyridinyl]methyl}amine (0.635 g, 2.99 mmol), andthe solution was heated at 150 °C and stirred for 86 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (2:3)to give 8-bromo-2-methyl-N-{[4-(trifluoromethyl)-3-pyridinyl]-methyl}-4-quinolinamine 3p (0.1592 g, 0.382 mmol, 19% yield). 1HNMR (400 MHz, CD3SOCD3): δ 8.78 (d, 1H, J = 5 Hz), 8.75 (s, 1H),8.24 (d, 1H, J = 7 Hz), 7.98 (d, 1H, J = 7 Hz), 7.83 (br t, 1H, J =5 Hz), 7.79 (d, 1H, J = 5 Hz), 7.30 (t, 1H, J = 8 Hz), 6.36 (s, 1H), 4.71(d, 2H, J = 5 Hz), 2.43 (s, 3H); LC-MS (LC-ES) M + H = 396.

2-Methyl-4-({[4-(trifluoromethyl)-3-pyridinyl]methyl}-amino)-8-quinolinecarboxamide (1ap).

N,N-Diisopropylethylamine (0.154 mL, 0.884 mmol) and hexame-thyldisilazane (0.590 mL, 2.81 mmol) were added to 8-bromo-2-methyl-N-{[4-(trifluoromethyl)-3-pyridinyl]methyl}-4-quinolinamine3p (0.1592 g, 0.402 mmol) in N,N-dimethylformamide (8.04 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.050 g, 0.121 mmol) and palladium(II) acetate (0.018 g, 0.080 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with methanol/ethyl acetate(1:99) to give 2-methyl-4-({[4-(trifluoromethyl)-3-pyridinyl]methyl}-amino)-8-quinolinecarboxamide 1ap (0.0716 g, 0.189 mmol, 47%yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.05 (br d, 1H, J =5 Hz), 8.79 (d, 1H, J = 5 Hz), 8.76 (s, 1H), 8.50 (d, 1H, J = 7 Hz),8.43 (d, 1H, J = 8 Hz), 7.97 (br t, 1H, J = 5 Hz), 7.80 (d, 1H, J =5 Hz), 7.71 (br d, 1H, J = 4 Hz), 7.51 (t, 1H, J = 8 Hz), 6.39 (s, 1H),4.73 (d, 2H, J = 5 Hz), 2.32 (s, 3H); HRMS: C18H15F3N4O requiresM + H at m/z 361.1276; found, 361.1273; tR = 0.54 min, 96.7% purity.

8-Bromo-N-[(3-chloro-4-pyridinyl)methyl]-2-methyl-4-qui-nolinamine (3q).

N,N-Diisopropylethylamine (1.397 mL, 8.00 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5128 g, 1.999 mmol)in dimethyl sulfoxide (6.66 mL) at room temperature, followed by[(3-chloro-4-pyridinyl)methyl]amine (0.646 g, 3.00 mmol), and thesolution was heated at 150 °C and stirred for 44 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:1)to give 8-bromo-N-[(3-chloro-4-pyridinyl)methyl]-2-methyl-4-quino-linamine 3q (0.0927 g, 0.230 mmol, 12% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.64 (s, 1H), 8.42 (d, 1H, J = 5 Hz), 8.25 (d, 1H, J =8 Hz), 7.99 (d, 1H, J = 7 Hz), 7.90 (br t, 1H, J = 6 Hz), 7.31 (t, 1H,J = 8 Hz), 7.25 (d, 1H, J = 5 Hz), 6.28 (s, 1H), 4.63 (d, 2H, J = 6 Hz),2.40 (s, 3H); LC-MS (LC-ES) M + H = 362.



7044


4-{[(3-Chloro-4-pyridinyl)methyl]amino}-2-methyl-8-quinoli-necarboxamide (1aq).

N,N-Diisopropylethylamine (0.098 mL, 0.562 mmol) and hexame-thyldisilazane (0.375 mL, 1.789 mmol) were added to 8-bromo-N-[(3-chloro-4-pyridinyl)methyl]-2-methyl-4-quinolinamine 3q (0.0927 g,0.256 mmol) in N,N-dimethylformamide (5.11 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.032 g,0.077 mmol) and palladium(II) acetate (0.011 g, 0.051 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with methanol/ethyl acetate(1:99) to give 4-{[(3-chloro-4-pyridinyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1aq (0.0244 g, 0.071 mmol, 28% yield). 1HNMR (400 MHz, CD3SOCD3): δ 11.05 (br d, 1H, J = 5 Hz), 8.65 (s,1H), 8.51 (d, 1H, J = 7 Hz), 8.44 (d, 1H, J = 8 Hz), 8.42 (d, 1H, J =5 Hz), 8.06 (br t, 1H, J = 6 Hz), 7.70 (br d, 1H, J = 5 Hz), 7.53 (t, 1H,J = 8 Hz), 7.27 (d, 1H, J = 5 Hz), 6.31 (s, 1H), 4.66 (d, 2H, J = 6 Hz),2.44 (s, 3H); HRMS: C17H15ClN4O requires M + H at m/z 327.1012;found, 327.1010; tR = 0.47 min, 95.9% purity.8-Bromo-2-methyl-N-{[2-(trifluoromethyl)-3-pyridinyl]-

methyl}-4-quinolinamine (3r).

N,N-Diisopropylethylamine (1.370 mL, 7.84 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5029 g, 1.960 mmol) indimethyl sulfoxide (6.53 mL) at room temperature, followed by{[2-(trifluoromethyl)-3-pyridinyl]methyl}amine (0.518 g, 2.94 mmol),and the solution was heated at 150 °C and stirred for 88 h. Thereaction mixture was cooled, poured into ether, washed with water,dried over magnesium sulfate, filtered, and concentrated. The residuewas purified by silica gel chromatography, eluting with ethyl acetate/hexanes (2:3) to give 8-bromo-2-methyl-N-{[2-(trifluoromethyl)-3-pyridinyl]methyl}-4-quinolinamine 3r (0.3018 g, 0.724 mmol, 37%yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.64 (d, 1H, J = 5 Hz),8.24 (d, 1H, J = 8 Hz), 7.98 (d, 1H, J = 7 Hz), 7.91 (br t, 1H, J =5 Hz), 7.90 (d, 1H, J = 8 Hz), 6.65 (dd, 1H, J = 8, 5 Hz), 7.31 (t, 1H,J = 8 Hz), 6.27 (s, 1H), 4.73 (d, 2H, J = 5 Hz), 2.40 (s, 3H); LC-MS(LC-ES) M + H = 396.2-Methyl-4-({[2-(trifluoromethyl)-3-pyridinyl]methyl}-

amino)-8-quinolinecarboxamide (1ar).

N,N-Diisopropylethylamine (0.141 mL, 0.808 mmol) and hexame-thyldisilazane (0.539 mL, 2.57 mmol) were added to 8-bromo-2-methyl-N-{[2-(trifluoromethyl)-3-pyridinyl]methyl}-4-quinolinamine

3r (0.1455 g, 0.367 mmol) in N,N-dimethylformamide (3.67 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.045 g, 0.110 mmol) and palladium(II) acetate (0.016 g, 0.073 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with ethyl acetate togive 2-methyl-4-({[2-(trifluoromethyl)-3-pyridinyl]methyl}amino)-8-quinolinecarboxamide 1ar (0.0387 g, 0.102 mmol, 28% yield).1H NMR (400 MHz, CD3SOCD3): δ 11.05 (br d, 1H, J = 5 Hz), 8.65(d, 1H, J = 5 Hz), 8.51 (d, 1H, J = 7 Hz), 8.44 (d, 1H, J = 8 Hz), 8.06(br t, 1H, J = 5 Hz), 7.92 (d, 1H, J = 8 Hz), 7.71 (br d, 1H, J = 5 Hz),7.66 (dd, 1H, J = 8, 5 Hz), 7.52 (t, 1H, J = 8 Hz), 6.31 (s, 1H), 4.75(d, 2H, J = 5 Hz), 2.44 (s, 3H); HRMS: C18H15F3N4O requiresM + H at m/z 361.1276; found, 361.1272; tR = 0.54 min, 100.0%purity.

8-Bromo-N-[(3-chloro-2-thienyl)methyl]-2-methyl-4-quino-linamine (3s).

N,N-Diisopropylethylamine (0.684 mL, 3.92 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5026 g, 1.959 mmol)in dimethyl sulfoxide (6.53 mL) at room temperature, followed by[(3-chloro-2-thienyl)methyl]amine (0.434 g, 2.94 mmol), and thesolution was heated at 150 °C and stirred for 88 h. The reactionmixture was cooled, poured into ether, washed with water, driedover magnesium sulfate, filtered, and concentrated. The residuewas purified by silica gel chromatography, eluting with ethylacetate/hexanes (1:4) to give 8-bromo-N-[(3-chloro-2-thienyl)-methyl]-2-methyl-4-quinolinamine 3s (0.1573 g, 0.406 mmol, 21%yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.18 (d, 1H, J =8 Hz), 7.96 (d, 1H, J = 7 Hz), 7.95 (br t, 1H, J = 5 Hz), 7.53 (d,1H, J = 5 Hz), 7.28 (t, 1H, J = 8 Hz), 7.05 (d, 1H, J = 5 Hz), 6.45(s, 1H), 4.66 (d, 2H, J = 6 Hz), 2.45 (s, 3H); LC-MS (LC-ES) M +H = 367.

4-{[(3-Chloro-2-thienyl)methyl]amino}-2-methyl-8-quinoli-necarboxamide (1as).

N,N-Diisopropylethylamine (0.164 mL, 0.941 mmol) and hexame-thyldisilazane (0.628 mL, 2.99 mmol) were added to 8-bromo-N-[(3-chloro-2-thienyl)methyl]-2-methyl-4-quinolinamine 3s (0.1573 g,0.428 mmol) in N,N-dimethylformamide (8.56 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.053 g,0.128 mmol) and palladium(II) acetate (0.019 g, 0.086 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 1 h. The reaction mixture was cooled,poured into ether, washed with 1 N sodium hydroxide and water,dried over magnesium sulfate, filtered, and concentrated. Theresidue was purified by silica gel chromatography, eluting with ethylacetate/hexanes (4:1) to give 4-{[(3-chloro-2-thienyl)methyl]-amino}-2-methyl-8-quinolinecarboxamide 1as (0.0648 g, 0.186 mmol,43% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.05 (br d, 1H,J = 5 Hz), 8.49 (d, 1H, J = 7 Hz), 8.38 (d, 1H, J = 7 Hz), 8.11(br t, 1H, J = 6 Hz), 7.70 (br d, 1H, J = 5 Hz), 7.54 (d, 1H, J =5 Hz), 7.49 (t, 1H, J = 8 Hz), 7.06 (d, 1H, J = 5 Hz), 6.48 (s, 1H),



7045


4.69 (d, 2H, J = 6 Hz), 2.49 (s, 3H); HRMS: C16H14ClN3OS requiresM + H at m/z 332.0624; found, 332.0623; tR = 0.54 min, 100.0%purity.8-Bromo-N-[(3,5-dimethyl-4-isoxazolyl)methyl]-2-methyl-4-

quinolinamine (3t).

N,N-Diisopropylethylamine (1.034 mL, 5.92 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5062 g, 1.973 mmol) indimethyl sulfoxide (6.58 mL) at room temperature, followed by [(3,5-dimethyl-4-isoxazolyl)methyl]amine (0.373 g, 2.96 mmol), and thesolution was heated at 150 °C and stirred for 16 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (2:3)to give 8-bromo-N-[(3,5-dimethyl-4-isoxazolyl)methyl]-2-methyl-4-quinolinamine 3t (0.4127 g, 1.132 mmol, 57% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.22 (d, 1H, J = 8 Hz), 7.93 (d, 1H, J =7 Hz), 7.34 (br t, 1H, J = 5 Hz), 7.34 (t, 1H, J = 8 Hz), 6.45 (s, 1H),4.23 (d, 2H, J = 5 Hz), 2.49 (s, 3H), 2.39 (s, 3H), 2.18 (s, 3H);LC-MS (LC-ES) M + H = 346.4-{[(3,5-Dimethyl-4-isoxazolyl)methyl]amino}-2-methyl-8-

quinolinecarboxamide (1at).

N,N-Diisopropylethylamine (0.242 mL, 1.385 mmol) and hexame-thyldisilazane (0.923 mL, 4.41 mmol) were added to 8-bromo-N-[(3,5-dimethyl-4-isoxazolyl)methyl]-2-methyl-4-quinolinamine 3t(0.2179 g, 0.629 mmol) in N,N-dimethylformamide (12.59 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.078 g, 0.189 mmol) and palladium(II) acetate (0.028 g, 0.126 mmol),and the solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with methanol/ethyl acetate(1:99) to give 4-{[(3,5-dimethyl-4-isoxazolyl)methyl]amino}-2-meth-yl-8-quinolinecarboxamide 1at (0.0337 g, 0.103 mmol, 16% yield).1H NMR (400 MHz, CD3SOCD3): δ 11.12 (br d, 1H, J =5 Hz), 8.47 (d, 1H, J = 7 Hz), 8.41 (d, 1H, J = 8 Hz), 7.69 (br d, 1H,J = 5 Hz), 7.50 (br t, 1H, J = 5 Hz), 7.44 (t, 1H, J = 8 Hz), 6.48 (s,1H), 4.28 (d, 2H, J = 5 Hz), 2.53 (s, 3H), 2.40 (s, 3H), 2.19 (s, 3H);HRMS: C17H18N4O2 requires M + H at m/z 311.1508; found,311.1502; tR = 0.43 min, 97.0% purity.8-Bromo-N-(cyclohexylmethyl)-2-methyl-4-quinolinamine (3u).

(Cyclohexylmethyl)amine (88 mg, 0.780 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (100 mg, 0.390 mmol) inN-methyl-2-pyrrolidone (2 mL). Then, N,N-diisopropylethylamine

(0.2 mL, 1.145 mmol) was added, and the reaction mixture was heatedat 150 °C overnight. The reaction mixture was diluted with ethylacetate and washed with brine (2×), dried over magnesium sulfate,and filtered. The solution was evaporated onto silica gel and purifiedby silica gel chromatography, eluting with ethyl acetate/hexane (1:9 to1:0) to give 8-bromo-N-(cyclohexylmethyl)-2-methyl-4-quinolinamine3u (90 mg, 0.243 mmol, 62% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.22 (d, 1H, J = 8 Hz), 7.92 (d, 1H, J = 7 Hz),7.22 (t, 1H, J = 8 Hz), 7.17 (br t, 1H, J = 6 Hz), 6.42 (s, 1H), 3.10 (t,2H, J = 6 Hz), 2.49 (s, 3H), 1.82 (br d, 2H, J = 13 Hz), 1.76−1.58(m, 4H), 1.28−1.10 (m, 3H), 1.04−0.90 (m, 2H); LC-MS (LC-ES)M + H = 333.

4-[(Cyclohexylmethyl)amino]-2-methyl-8-quinolinecarboxa-mide (1au).

Hexamethyldisilazane (0.849 mL, 4.05 mmol) was added to a solutionof 8-bromo-N-(cyclohexylmethyl)-2-methyl-4-quinolinamine 3u (90 mg,0.270 mmol) in N,N-dimethylformamide (2 mL), followed by 1,1′-bis(diphenylphosphino)ferrocene (14.97 mg, 0.027 mmol) andtris(dibenzylideneacetone)dipalladium(0) (12.36 mg, 0.014 mmol).This solution was purged with nitrogen, evacuated, and treated withcarbon monoxide. The reaction mixture was heated at 100 °C, and thereaction mixture was again evacuated and purged with carbonmonoxide. The reaction was then stirred under carbon monoxide for2 h. The solution was cooled and extracted into ethyl acetate (2×),washed with water (2×), dried over magnesium sulfate, and filtered.The solution was evaporated onto silica gel and purified by silica gelchromatography, eluting with ethyl acetate/hexane (4:1 to 1:0) to give4-[(cyclohexylmethyl)amino]-2-methyl-8-quinolinecarboxamide 1au(65 mg, 0.208 mmol, 77% yield) as a orange solid. 1H NMR(400 MHz, CD3SOCD3): δ 11.22 (br d, 1H, J = 5 Hz), 8.46 (dd, 1H,J = 8, 1 Hz), 8.41 (dd, 1H, J = 8, 1 Hz), 7.66 (br d, 1H, J = 5 Hz), 7.43(t, 1H, J = 8 Hz), 7.36 (br t, 1H, J = 6 Hz), 6.45 (s, 1H), 3.13 (t, 2H,J = 6 Hz), 2.52 (s, 3H), 1.81 (br d, 2H, J = 12 Hz), 1.78−1.58 (m,4H), 1.28−1.12 (m, 3H), 1.04−0.92 (m, 2H); HRMS: C18H23N3Orequires M + H at m/z 298.1919; found, 298.1917; tR = 0.65 min,100.0% purity.

N-[(1-Acetyl-4-piperidinyl)methyl]-8-bromo-2-methyl-4-qui-nolinamine (3v).

8-Bromo-4-chloro-2-methylquinoline 2a (0.15 g, 0.585 mmol),methanamine-1-acetyl-4-methylpiperidine (1:1) (0.119 g, 0.760 mmol),and N,N-diisopropylethylamine (0.15 mL, 0.859 mmol) in N-methyl-2-pyrrolidone (1.8 mL) were heated at 130 °C for 3 days. Aftercooling to room temperature, the reaction mixture was diluted withethyl acetate, washed with water, then brine, dried over sodium sulfate,filtered, and concentrated under reduced pressure. The residue wasdried onto Celite and purified by reverse-phase liquid chromatography,eluting with acetonitrile/water with 0.1% trifluoroacetic acid (1:9 to1:0). The combined fractions were diluted with ethyl acetate andwashed with 1.0 N aqueous sodium hydroxide. The organics weredried over sodium sulfate, filtered, and then concentrated under



7046


reduced pressure to give N-[(1-acetyl-4-piperidinyl)methyl]-8-bromo-2-methyl-4-quinolinamine 3v (161 mg, 0.428 mmol, 73% yield) as apale solid. LC-MS (LC-ES) M + H = 376.4-{[(1-Acetyl-4-piperidinyl)methyl]amino}-2-methyl-8-qui-

nolinecarboxamide (1av).

N-[(1-Acetyl-4-piperidinyl)methyl]-8-bromo-2-methyl-4-quinolin-amine 3v (0.16g, 0.425 mmol), hexamethyldisilazane (1.337 mL,6.38 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.019 g,0.021 mmol), and 1,1′-bis(diphenylphosphino)ferrocene (0.024 g,0.043 mmol) in N,N-dimethylformamide (2.5 mL) were stirred undernitrogen and then fitted with a balloon of carbon monoxide. The vesselwas evacuated and filled with carbon monoxide, heated at 100 °C, andstirred for 2 h. After cooling to room temperature, the reaction mixturewas filtered through a pad of Celite and washed with ethyl acetate.The filtrate was washed with water and brine, and the combinedorganics were dried over sodium sulfate, filtered, and concentratedunder reduced pressure. The residue was taken up in dichloromethane,dried onto Celite, and purified by reverse-phase liquid chromatography,eluting with acetonitrile/water with 0.1% trifluoroacetic acid (1:9 to1:0). The combined fractions were diluted with ethyl acetate andwashed with 1.0 N aqueous sodium hydroxide and brine. The organicswere dried over magnesium sulfate, filtered, and concentrated underreduced pressure to give 4-{[(1-acetyl-4-piperidinyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1av (63 mg, 0.178 mmol, 42% yield).1H NMR (400 MHz, CD3OD): δ 8.54 (dd, 1H, J = 8, 1 Hz), 8.26 (dd,1H, J = 8, 1 Hz), 7.43 (t, 1H, J = 8 Hz), 6.47 (s, 1H), 4.55 (d, 1H, J =13 Hz), 3.94 (d, 1H, J = 14 Hz), 3.27 (d, 2H, J = 7 Hz), 3.11 (dt, 1H,J = 13, 2 Hz), 2.70−2.54 (m, 2H), 2.57 (s, 3H), 2.09 (s, 3H), 1.90 (t,2H, J = 16 Hz), 1.36−1.12 (m, 2H); HRMS: C19H24N4O2 requiresM + H at m/z 341.1977; found, 341.1978; tR = 0.35 min, 95.9% purity.8-Bromo-2-methyl-N-[(1-methyl-4-piperidinyl)methyl]-4-

quinolinamine (3w).

8-Bromo-4-chloro-2-methylquinoline 2a (0.15 g, 0.585 mmol), 1-(1-methyl-4-piperidinyl)methanamine (97 mg, 0.760 mmol), and N,N-diisopropylethylamine (0.15 mL, 0.859 mmol) in N-methyl-2-pyrrolidone (1.8 mL) were heated at 130 °C for 24 h. After coolingto room temperature, the reaction mixture was diluted with ethylacetate, washed with water and brine, dried over sodium sulfate,filtered, and concentrated under reduced pressure. The residue wasdried onto Celite and purified by reverse-phase liquid chromatography,eluting with acetonitrile/water with 0.1% trifluoroacetic acid (1:9 to1:0). The combined fractions were diluted with ethyl acetate andwashed with 1.0 N aqueous sodium hydroxide. The organics weredried over sodium sulfate, filtered, and concentrated under reducedpressure to give 8-bromo-2-methyl-N-[(1-methyl-4-piperidinyl)-methyl]-4-quinolinamine 3w (143 mg, 0.411 mmol, 70% yield) as apale solid. 1H NMR (400 MHz, CD3SOCD3): δ 8.22 (d, 1H, J =8 Hz), 7.93 (dd, 1H, J = 8, 1 Hz), 7.22 (t, 1H, J = 8 Hz), 7.17 (br t, 1H,J = 5 Hz), 6.44 (s, 1H), 3.15 (br t, 2H, J = 6 Hz), 2.76 (br d, 2H,

J = 11 Hz), 2.49 (s, 3H), 2.14 (s, 3H), 1.81 (br t, 2H, J = 12 Hz), 1.77(br d, 2H, J = 12 Hz), 1.62−1.78 (m, 1H), 1.25 (dq, 2H, J = 12, 3 Hz);LC-MS (LC-ES) M + H = 350.

2-Methyl-4-{[(1-methyl-4-piperidinyl)methyl]amino}-8-qui-nolinecarboxamide (1aw).

8-Bromo-2-methyl-N-[(1-methyl-4-piperidinyl)methyl]-4-quinolin-amine 3w (0.14 g, 0.402 mmol), hexamethyldisilazane (1.264 mL,6.03 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.018 g,0.020 mmol), and 1,1′-bis(diphenylphosphino)ferrocene (0.022 g,0.040 mmol) in N,N-dimethylformamide (2.5 mL) were stirred undernitrogen and then fitted with a balloon of carbon monoxide. The vesselwas evacuated, filled with carbon monoxide, heated at 100 °C, andstirred for 2 h. After cooling to room temperature, the reaction mixturewas filtered through a pad of Celite and washed with ethyl acetate. Thefiltrate was washed with water and brine, and the combined organicswere dried over sodium sulfate, filtered, and concentrated underreduced pressure. The residue was taken up in dichloromethane, driedonto Celite, and purified by reverse-phase liquid chromatography,eluting with acetonitrile/water with 0.1% trifluoroacetic acid (1:9 to1:0). The combined fractions were diluted with ethyl acetate andwashed with 1.0 N aqueous sodium hydroxide. The organics weredried over magnesium sulfate, filtered, and concentrated underreduced pressure to give 2-methyl-4-{[(1-methyl-4-piperidinyl)-methyl]amino}-8-quinolinecarboxamide 1aw (17.6 mg, 0.054 mmol,13% yield) as a yellow solid. 1H NMR (400 MHz, CD3OD): δ 8.54(dd, 1H, J = 8, 1 Hz), 8.27 (d, 1H, J = 8 Hz), 7.43 (t, 1H, J = 8 Hz),6.47 (s, 1H), 3.27 (br d, 2H, J = 6 Hz), 2.91 (br d, 2H, J = 12 Hz),2.58 (s, 3H), 2.28 (s, 3H), 2.03 (br t, 2H, J = 6 Hz), 1.86 (br d, 2H, J =6 Hz), 1.88−1.76 (m, 1H), 1.38 (br q, 2H, J = 12 Hz); HRMS:C18H24N4O requires M + H at m/z 313.2028; found, 313.2029; tR =0.26 min, 100.0% purity.

8-Bromo-2-methyl-N-[(1R)-1-(2-methylphenyl)ethyl]-4-qui-nolinamine (3x).

N,N-Diisopropylethylamine (0.693 mL, 3.97 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5092 g, 1.985 mmol) indimethyl sulfoxide (6.62 mL) at room temperature, followed by [(1R)-1-(2-methylphenyl)ethyl]amine (0.403 g, 2.98 mmol), and thesolution was heated at 150 °C and stirred for 16 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:3)to give 8-bromo-2-methyl-N-[(1R)-1-(2-methylphenyl)ethyl]-4-quino-linamine 3x (0.1476 g, 0.395 mmol, 20% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.49 (d, 1H, J = 8 Hz), 7.95 (d, 1H, J = 7 Hz), 7.43 (d,1H, J = 7 Hz), 7.33 (dd, 1H, J = 7, 2 Hz), 7.28 (t, 1H, J = 8 Hz), 7.18(dd, 1H, J = 7, 2 Hz), 7.13−7.05 (m, 2H), 6.00 (s, 1H), 4.87 (p, 1H,J = 7 Hz), 2.45 (s, 3H), 2.32 (s, 3H), 1.54 (d, 3H, J = 7 Hz); LC-MS(LC-ES) M + H = 355.



7047


2-Methyl-4-{[(1R)-1-(2-methylphenyl)ethyl]amino}-8-quino-linecarboxamide (1ax).

N,N-Diisopropylethylamine (0.157 mL, 0.900 mmol) and hexame-thyldisilazane (0.600 mL, 2.86 mmol) were added to 8-bromo-2-methyl-N-[(1R)-1-(2-methylphenyl)ethyl]-4-quinolinamine 3x (0.1453 g,0.409 mmol) in N,N-dimethylformamide (8.18 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.051 g,0.123 mmol) and palladium(II) acetate (0.018 g, 0.082 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 18 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate to give 2-methyl-4-{[(1R)-1-(2-methylphenyl)ethyl]amino}-8-quinolinecarbox-amide 1ax (0.0417 g, 0.124 mmol, 30% yield). 1H NMR (400 MHz,CD3SOCD3): δ 11.07 (br d, 1H, J = 5 Hz), 8.68 (d, 1H, J = 8 Hz),8.48 (d, 1H, J = 6 Hz), 7.65 (br d, 1H, J = 5 Hz), 7.59 (d, 1H, J =7 Hz), 7.50 (t, 1H, J = 8 Hz), 7.34 (dd, 1H, J = 7, 3 Hz), 7.18 (dd, 1H,J = 6, 3 Hz), 7.14−7.06 (m, 2H), 6.03 (s, 1H), 4.91 (p, 1H, J = 7 Hz),2.46 (s, 3H), 2.36 (s, 3H), 1.56 (d, 3H, J = 7 Hz); HRMS: C20H21N3Orequires M + H at m/z 320.1763; found, 320.1763; tR = 0.64 min,96.6% purity.8-Bromo-N-[(1S)-1-(2,6-dimethylphenyl)ethyl]-2-methyl-4-

quinolinamine (3y).

N,N-Diisopropylethylamine (0.684 mL, 3.92 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5022 g, 1.958 mmol) indimethyl sulfoxide (6.53 mL) at room temperature, followed by [(1S)-1-(2,6-dimethylphenyl)ethyl]amine (0.438 g, 2.94 mmol), and thesolution was heated at 150 °C and stirred for 16 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (3:7)to give 8-bromo-N-[(1S)-1-(2,6-dimethylphenyl)ethyl]-2-methyl-4-quinolinamine 3y (0.1275 g, 0.311 mmol, 16% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.52 (d, 1H, J = 8 Hz), 7.94 (d, 1H, J =7 Hz), 7.30 (br d, 1H, J = 5 Hz), 7.27 (t, 1H, J = 8 Hz), 7.02−6.92 (m,3H), 5.77 (s, 1H), 4.08 (p, 1H, J = 5 Hz), 2.39 (s, 6H), 2.26 (s, 3H),1.63 (d, 3H, J = 7 Hz); LC-MS (LC-ES) M + H = 369.4-{[(1S)-1-(2,6-Dimethylphenyl)ethyl]amino}-2-methyl-8-

quinolinecarboxamide (1ay).

N,N-Diisopropylethylamine (0.133 mL, 0.760 mmol) and hexame-thyldisilazane (0.507 mL, 2.417 mmol) were added to 8-bromo-N-[(1S)-1-(2,6-dimethylphenyl)ethyl]-2-methyl-4-quinolinamine 3y

(0.1275 g, 0.345 mmol) in N,N-dimethylformamide (6.90 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.043 g, 0.104 mmol) and palladium(II) acetate (0.016 g, 0.069 mmol),and the solution was fitted with a carbon monoxide balloon, heatedat 110 °C, and stirred for 18 h. The reaction mixture was cooled,poured into ether, washed with 1 N sodium hydroxide and water, driedover magnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with ethyl acetate togive 4-{[(1S)-1-(2,6-dimethylphenyl)ethyl]amino}-2-methyl-8-quino-linecarboxamide 1ay (0.0418 g, 0.119 mmol, 35% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.06 (br d, 1H, J = 5 Hz), 8.72 (d, 1H,J = 8 Hz), 8.47 (d, 1H, J = 7 Hz), 7.63 (br d, 1H, J = 5 Hz), 7.49 (t,1H, J = 8 Hz), 7.47 (br d, 1H, J = 5 Hz), 7.02−6.92 (m, 3H), 5.78 (s,1H), 4.98 (p, 1H, J = 6 Hz), 2.40 (s, 6H), 2.30 (s, 3H), 1.65 (d, 3H,J = 7 Hz); HRMS: C21H23N3O requires M + H at m/z 334.1919;found, 334.1919; tR = 0.72 min, 94.8% purity.

8-Bromo-2-methyl-N-[(1R)-1,2,3,4-tetrahydro-1-naphthalen-yl]-4-quinolinamine (3z).

N,N-Diisopropylethylamine (0.694 mL, 3.97 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5096 g, 1.987 mmol) indimethyl sulfoxide (6.62 mL) at room temperature, followed by (1R)-1,2,3,4-tetrahydro-1-naphthalenamine (0.439 g, 2.98 mmol), and thesolution was heated at 160 °C and stirred for 40 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:4)to give 8-bromo-2-methyl-N-[(1R)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-quinolinamine 3z (0.0849 g, 0.220 mmol, 11% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.31 (d, 1H, J = 8 Hz), 7.93 (d, 1H, J =7 Hz), 7.35 (d, 1H, J = 9 Hz), 7.22−7.08 (m, 5H), 6.72 (s, 1H), 5.04−4.94 (s, 1H), 2.88−2.74 (m, 2H), 2.49 (s, 3H), 2.10−1.76 (m, 4H);LC-MS (LC-ES) M + H = 369.

2-Methyl-4-[(1R)-1,2,3,4-tetrahydro-1-naphthalenylamino]-8-quinolinecarboxamide (1az).

N,N-Diisopropylethylamine (0.213 mL, 1.217 mmol) and hexame-thyldisilazane (0.812 mL, 3.87 mmol) were added to 8-bromo-2-methyl-N-[(1R)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-quinolinamine3z (0.2032 g, 0.553 mmol, from multiple batches) in N,N-dimethylformamide (10.04 mL) at room temperature, followed by1,3-bis(diphenylphosphino)propane (0.068 g, 0.166 mmol) andpalladium(II) acetate (0.025 g, 0.111 mmol), and the solution wasfitted with a carbon monoxide (1.661 g, 55.3 mmol) balloon, heated at110 °C, and stirred for 16 h. The reaction mixture was cooled, pouredinto ether, washed with 1 N sodium hydroxide and water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate to give2-methyl-4-[(1R)-1,2,3,4-tetrahydro-1-naphthalenylamino]-8-quinoli-necarboxamide 1az (0.0277 g, 0.079 mmol, 14% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.22 (d, 1H, J = 5 Hz), 8.49 (d, 1H, J =8 Hz), 8.47 (d, 1H, J = 8 Hz), 7.67 (d, 1H, J = 5 Hz), 7.53 (d, 1H, J =9 Hz), 7.39 (t, 1H, J = 8 Hz), 7.22−7.08 (m, 4H), 6.75 (s, 1H),5.07−4.94 (s, 1H), 2.90−2.74 (m, 2H), 2.53 (s, 3H), 2.10−1.74 (m,



7048


4H); HRMS: C21H21N3O requires M + H at m/z 332.1763; found,332.1755; tR = 0.67 min, 100.0% purity.8-Bromo-2-methyl-N-[(1S)-1,2,3,4-tetrahydro-1-naphthalen-

yl]-4-quinolinamine (3aa).

N,N-Diisopropylethylamine (0.695 mL, 3.98 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.5104 g, 1.990 mmol) indimethyl sulfoxide (6.63 mL) at room temperature, followed by (1S)-1,2,3,4-tetrahydro-1-naphthalenamine (0.439 g, 2.98 mmol), and thesolution was heated at 160 °C and stirred for 66 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:4)to give 8-bromo-2-methyl-N-[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-quinolinamine 3aa (0.1043 g, 0.270 mmol, 14% yield). 1H NMR(400 MHz, CD3SOCD3): δ 8.31 (d, 1H, J = 8 Hz), 7.93 (d, 1H, J =7 Hz), 7.35 (d, 1H, J = 9 Hz), 7.22−7.08 (m, 5H), 6.72 (s, 1H), 5.04−4.94 (s, 1H), 2.88−2.74 (m, 2H), 2.49 (s, 3H), 2.10−1.76 (m, 4H);LC-MS (LC-ES) M + H = 367.2-Methyl-4-[(1S)-1,2,3,4-tetrahydro-1-naphthalenylamino]-

8-quinolinecarboxamide (1ba).

N,N-Diisopropylethylamine (0.109 mL, 0.625 mmol) and hexame-thyldisilazane (0.417 mL, 1.988 mmol) were added to 8-bromo-2-methyl-N-[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]-4-quinolinamine3aa (0.1043 g, 0.284 mmol) in N,N-dimethylformamide (5.68 mL) atroom temperature, followed by 1,3-bis(diphenylphosphino)propane(0.035 g, 0.085 mmol) and palladium(II) acetate (0.013 g, 0.057 mmol),and the solution was fitted with a carbon monoxide balloon, heatedat 110 °C, and stirred for 16 h. The reaction mixture was cooled,poured into ether, washed with 1 N sodium hydroxide and water, driedover magnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with ethyl acetate to give2-methyl-4-[(1S)-1,2,3,4-tetrahydro-1-naphthalenylamino]-8-quinoli-necarboxamide 1ba (0.0512 g, 0.147 mmol, 52% yield). 1H NMR(400 MHz, CD3SOCD3): δ 11.22 (d, 1H, J = 5 Hz), 8.49 (d, 1H, J =8 Hz), 8.47 (d, 1H, J = 8 Hz), 7.67 (d, 1H, J = 5 Hz), 7.53 (d, 1H, J =8 Hz), 7.39 (t, 1H, J = 8 Hz), 7.22−7.08 (m, 4H), 6.75 (s, 1H), 5.07−4.94 (s, 1H), 2.90−2.74 (m, 2H), 2.53 (s, 3H), 2.10−1.74 (m, 4H);HRMS: C21H21N3O requires M + H at m/z 332.1763; found,332.1759; tR = 0.67 min, 88.2% purity.8-Bromo-N-(2,6-dichlorobenzyl)-N,2-dimethylquinolin-4-

amine (3ab).

N,N-Diisopropylethylamine (0.317 mL, 1.822 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (0.1558 g, 0.607 mmol) in

dimethyl sulfoxide (1.707 mL) at room temperature, followed by1-(2,6-dichlorophenyl)-N-methylmethanamine (0.173 g, 0.911 mmol),and the solution was heated at 150 °C for 64 h. The reaction mixturewas poured into ether and methanol, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:4)to give 8-bromo-N-(2,6-dichlorobenzyl)-N,2-dimethylquinolin-4-amine 3ab (0.0888 g, 0.206 mmol, 34% yield). 1H NMR (400 MHz,CD3SOCD3): δ 7.99 (d, 1H, J = 4 Hz), 7.97 (d, 1H, J = 4 Hz), 7.53 (s,1H), 7.51 (s, 1H), 7.39 (dd, 1H, J = 8, 7 Hz), 7.31 (t, 1H, J = 8 Hz),7.13 (s, 1H), 4.72 (br s, 2H), 2.82 (s, 3H), 2.61 (s, 3H); LC-MS (LC-ES)M + H = 410.

4-((2,6-Dichlorobenzyl) (methyl)amino)-2-methylquinoline-8-carboxamide (1bb).

1,1′-Bis(diphenylphosphino)ferrocene (0.024 g, 0.043 mmol) andbis(trimethylsilyl)amine (0.685 mL, 3.25 mmol) were added to8-bromo-N-(2,6-dichlorobenzyl)-N,2-dimethylquinolin-4-amine 3ab(0.0888 g, 0.217 mmol) in N,N-dimethylformamide (1.480 mL) atroom temperature, followed by tris(dibenzylideneacetone)dipalladium(0)(0.020 g, 0.022 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 100 °C, and stirred for 2 h. The reactionmixture was cooled, poured into ether, washed with 1 N sodiumhydroxide and water, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (4:1) to give 4-((2,6-dichloroben-zyl) (methyl)amino)-2-methylquinoline-8-carboxamide 1bb (0.0571 g,0.145 mmol, 67% yield). 1H NMR (400 MHz, CD3SOCD3): δ 10.74(br d, 1H, J = 4 Hz), 8.48 (dd, 1H, J = 7, 1 Hz), 8.16 (dd, 1H, J = 8,1 Hz), 7.78 (br d, 1H, J = 4 Hz), 7.56−7.48 (m, 3H), 7.40 (dd, 1H,J = 8, 7 Hz), 7.15 (s, 1H), 4.76 (s, 2H), 2.85 (s, 3H), 2.64 (s, 3H);HRMS: C19H17Cl2N3O requires M + H at m/z 374.0827; found,374.0820; tR = 0.56 min, 98.9% purity.

2,6-Dichloro-N-(8-cyano-2-methyl-4-quinolinyl)benzamide(4ac).

Thionyl chloride (15 mL, 1.092 mmol) was added to 2,6-dichlorobenzoic acid (1043 mg, 5.46 mmol), and the reaction mixturewas stirred under nitrogen at 70 °C for 1 h and then concentrated.The residue was dissolved in tetrahydrofuran (5 mL) and added to asolution of 4-amino-2-methyl-8-quinolinecarbonitrile 4h (200 mg,1.092 mmol) and lithium hexamethyldisilazide (0.458 mL, 2.183mmol) in tetrahydrofuran (20 mL) dropwise during 15 min at−75 °C. The reaction mixture was stirred at −75 °C for 10 h, water(30 mL) was added, and the reaction mixture was extracted with ethylacetate and concentrated. The residue was washed with diethylether to give 2,6-dichloro-N-(8-cyano-2-methyl-4-quinolinyl)-benzamide 4ac (200 mg, 0.561 mmol, 51% yield) as a mixturewith the bis-acylated 2,6-dichloro-N-(8-cyano-2-methylquinolin-4-yl)-N-(2,6-dichlorobenzoyl)benzamide. LC-MS (LC-ES) M +H = 356.



7049


4-(2,6-Dichlorobenzamido)-2-methylquinoline-8-carboxa-mide (1bc).

Sodium hydroxide (300 mg, 7.50 mmol) was added to 2,6-dichloro-N-(8-cyano-2-methyl-4-quinolinyl)benzamide 4ac containing 2,6-dichloro-N-(8-cyano-2-methylquinolin-4-yl)-N-(2,6-dichlorobenzoyl)-benzamide (300 mg, 0.567 mmol combined) in dimethyl sulfoxide(10 mL). Then, 30% hydrogen peroxide (3 mL, 29.4 mmol) wasadded. Once the reaction was complete, the reaction mixture wasextracted with ethyl acetate and washed with water. The organic layerwas dried over magnesium sulfate, filtered, and concentrated. Theresidue was purified by preparative high-performance chromatography,eluting with acetonitrile/water with 10 mM ammonium bicarbonate(5:95 to 95:5) to give 4-(2,6-dichlorobenzamido)-2-methylquinoline-8-carboxamide 1bc (80 mg, 0.214 mmol, 38% yield) as a white solid.1H NMR (400 MHz, CD3SOCD3): δ 11.26 (br s, 1H), 10.43 (br d,1H, J = 4 Hz), 8.57 (dd, 1H, J = 7, 1 Hz), 8.44 (dd, 1H, J = 8, 2 Hz),8.08 (s, 1H), 7.89 (br d, 1H, J = 3 Hz), 7.72−7.52 (m, 4H), 2.76 (s,3H); HRMS: C18H13Cl2N3O2 requires M + H at m/z 374.0463; found,374.0452; tR = 1.61 min, 100.0% purity.4-(2,6-Dichlorobenzyloxy)-2-methylquinoline-8-carbonitrile

(4ad).

2-(Bromomethyl)-1,3-dichlorobenzene (86 mg, 0.358 mmol) wasadded to 4-hydroxy-2-methylquinoline-8-carbonitrile 6 (55 mg,0.289 mmol) in dry N,N-dimethylformamide (3 mL). Then, potassiumcarbonate (83 mg, 0.597 mmol) was added, and the reaction mixturewas stirred at 70 °C for 15 min. After cooling, the solid was collectedby filtration and dried to give 4-(2,6-dichlorobenzyloxy)-2-methyl-quinoline-8-carbonitrile 4ad (102 mg, 0.299 mmol, 99% yield) as awhite solid, which was used directly in next reaction without furtherpurification. LC-MS (LC-ES) M + H = 342.4-((2,6-Dichlorobenzyl)oxy)-2-methylquinoline-8-carboxa-

mide (1bd).

Potassium hydroxide (50 mg, 0.892 mmol) was added to 4-(2,6-dichlorobenzyloxy)-2-methylquinoline-8-carbonitrile 4ad (102 mg,0.297 mmol) in dimethyl sulfoxide (8 mL). Then, 30% hydrogenperoxide (3 mL) was added dropwise with stirring. The reactionmixture turned yellow, and upon cooling, a white solid appeared. Thesolid was collected by filtration, washed with methanol (5 mL), anddried to give 4-((2,6-dichlorobenzyl)oxy)-2-methylquinoline-8-carbox-amide (1bd) (75 mg, 0.206 mmol, 69% yield) as a white solid. 1HNMR (400 MHz, CD3SOCD3): δ 10.61 (br d, 1H, J = 3 Hz), 8.46(dd, 1H, J = 7, 1 Hz), 8.11 (d, 1H, J = 4 Hz), 7.85 (br d, 1H, J = 4 Hz),

7.86−7.60 (m, 2H), 7.58−52 (m, 2H), 7.38 (d, 1H, J = 2 Hz), 5.54 (s,2H), 2.73 (s, 3H); HRMS: C18H14Cl2N2O2 requires M + H at m/z361.0510; found, 361.0510; tR = 1.75 min, 99.1% purity.

8-Bromo-4-((2,6-dichlorobenzyl)thio)-2-methylquinoline(3ac).

Sodium hydride (0.039 g, 0.969 mmol) was added to (2,6-dichlorophenyl)methanethiol (0.203 g, 1.050 mmol) in dimethylsulfoxide (2.69 mL) at room temperature, followed by 8-bromo-4-chloro-2-methylquinoline 2a (0.2072 g, 0.808 mmol), and the solutionwas heated at 100 °C for 4 h. The reaction mixture was poured intoether and methanol, washed with water, dried over magnesium sulfate,filtered, and concentrated. The residue was purified by silica gelchromatography, eluting with ethyl acetate/hexanes (1:6) to give8-bromo-4-((2,6-dichlorobenzyl)thio)-2-methylquinoline 3ac (0.1487 g,0.342 mmol, 42% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.11 (d,1H, J = 7 Hz), 8.00 (d, 1H, J = 8 Hz), 7.66 (s, 1H), 7.57 (s, 1H), 7.55(s, 1H), 7.46−7.38 (m, 2H), 4.65 (br s, 2H), 2.70 (s, 3H); LC-MS(LC-ES) M + H = 413.

4-((2,6-Dichlorobenzyl)thio)-2-methylquinoline-8-carboxa-mide (1be).

1,1′-Bis(diphenylphosphino)ferrocene (0.040 g, 0.072 mmol) andbis(trimethylsilyl)amine (1.139 mL, 5.40 mmol) were added to8-bromo-4-((2,6-dichlorobenzyl)thio)-2-methylquinoline 3ac (0.1487 g,0.360 mmol) in N,N-dimethylformamide (2.460 mL) at roomtemperature, followed by tris(dibenzylideneacetone)dipalladium(0)(0.033 g, 0.036 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 100 °C, and stirred for 2 h. The reactionmixture was cooled, poured into ether, washed with 1 N sodiumhydroxide and water, dried over magnesium sulfate, filtered, andconcentrated. The residue was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (7:3) to give 4-((2,6-dichlorobenzyl)-thio)-2-methylquinoline-8-carboxamide 1be (0.0602 g, 0.152 mmol,42% yield). 1H NMR (400 MHz, CD3SOCD3): δ 10.39 (br d, 1H, J =4 Hz), 8.54 (dd, 1H, J = 7, 1 Hz), 8.18 (dd, 1H, J = 8, 1 Hz), 7.89 (br d,1H, J = 4 Hz), 7.70 (s, 1H), 7.63 (t, 1H, J = 8 Hz), 7.59 (s, 1H), 7.57 (s,1H), 7.44 (t, 1H, J = 8 Hz), 4.67 (s, 2H), 2.74 (s, 3H); HRMS:C18H14Cl2N2OS requires M + H at m/z 377.0282; found, 377.0278;tR = 0.88 min, 100.0% purity.

8-Bromo-6-fluoro-2-methylquinolin-4-ol (5b).

2,2-Dimethyl-5-[1-(methylthio)ethylidene]-1,3-dioxane-4,6-dione(991.5 mg, 4.58 mmol) and 2-bromo-4-fluoroaniline 8a (871 mg,4.58 mmol) were suspended in diphenyl ether (20 mL) and heated ina microwave to 240 °C for 30 min. The reaction was cooled to roomtemperature, and the mixture was allowed to stand overnight.The precipitated solid was collected by filtration and washed withdiethyl ether to give 8-bromo-6-fluoro-2-methyl-4-quinolinol 5b(0.2263 g, 0.884 mmol, 19% yield) as a red solid. 1H NMR (400 MHz,



7050


CD3SOCD3): δ 10.59 (br s, 1H), 8.04 (dd, 1H, J = 9, 3 Hz), 7.76 (dd,1H, J = 9, 3 Hz), 6.04 (br s, 1H), 2.46 (s, 3H).8-Bromo-4-chloro-6-fluoro-2-methylquinoline (2b).

8-Bromo-6-fluoro-2-methylquinolin-4-ol 5b (0.1 g, 0.391 mmol) wasadded to phosphorus oxychloride (0.5 mL, 5.36 mmol) and heated at90 °C for 2 h. The reaction was cooled to room temperature and thenpoured over ice and let sit overnight. A brown precipitate formed, wascollected, and then washed with ethyl acetate. The organics were driedwith magnesium sulfate, filtered, and concentrated under reducedpressure to give 8-bromo-4-chloro-6-fluoro-2-methylquinoline 2b (83 mg,0.302 mmol, 77% yield) as a brown solid. 1H NMR (400 MHz,CDCl3): δ 7.88 (dd, 1H, J = 8, 3 Hz), 7.82 (dd, 1H, J = 9, 3 Hz), 7.47(s, 1H), 2.78 (s, 3H); LC-MS (LC-ES) M + H = 276.8-Bromo-6-fluoro-2-methyl-N-(2,3,6-trichlorobenzyl)-

quinolin-4-amine (3ad).

8-Bromo-4-chloro-6-fluoro-2-methylquinoline 2b (0.083 g, 0.302 mmol),(2,3,6-trichlorophenyl)methanamine (0.046 mL, 0.363 mmol), and adrop of 6 N aqueous hydrochloric acid (0.050 mL, 0.302 mmol) inN-methyl-2-pyrrolidone (0.5 mL) were heated in a microwave at150 °C for 6 h. After cooling to room temperature, a precipitateformed, which was collected by filtration and washed with ethyl acetateto give 8-bromo-6-fluoro-2-methyl-N-(2,3,6-trichlorobenzyl)quinolin-4-amine 3ad (40 mg, 0.089 mmol, 29%) as a pale solid. 1H NMR(400 MHz, CD3OD): δ 8.30 (dd, 1H, J = 10, 3 Hz), 8.15 (dd, 1H,J = 7, 3 Hz), 7.80 (s, 1H), 7.62 (d, 1H, J = 9 Hz), 7.51 (d, 1H, J =9 Hz), 7.03 (s, 1H), 5.02 (s, 2H), 2.85 (s, 3H); LC-MS (LC-ES)M + H = 449.6-Fluoro-2-methyl-4-((2,3,6-trichlorobenzyl)amino)quinoline-

8-carboxamide (1bf).

A flask containing 8-bromo-6-fluoro-2-methyl-N -(2 ,3,6-trichlorobenzyl)quinolin-4-amine 3ad (0.04 g, 0.089 mmol), N,N-diisopropylethylamine (0.04 mL, 0.229 mmol), bis(trimethylsilyl)-amine (0.13 mL, 0.620 mmol), palladium(II) acetate (4.00 mg,0.018 mmol), and 1,3-bis(diphenylphosphino)propane (0.015 g,0.036 mmol) in N,N-dimethylformamide (0.8 mL) was evacuatedand filled with carbon monoxide (3×) via balloon. The reaction washeated at 120 °C for 3 h, cooled to room temperature, and poured intowater. The reaction mixture was extracted with ethyl acetate (2×), andthe combined organics were washed with brine, dried over magnesiumsulfate, filtered, and concentrated under reduced pressure. The residuewas purified by silica gel chromatography, eluting with ethyl acetate/hexanes (1:1) to give 6-fluoro-2-methyl-4-((2,3,6-trichlorobenzyl)-amino)quinoline-8-carboxamide 1bf (20 mg, 0.047 mmol, 53% yield)as a yellow solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.09 (br d,1H, J = 4 Hz), 8.32 (dd, 1H, J = 10, 3 Hz), 8.23 (dd, 1H, J = 10, 3 Hz),7.91 (br d, 1H, J = 4 Hz), 7.75 (d, 1H, J = 9 Hz), 7.62 (d, 1H, J = 9 Hz),

7.25 (br t, 1H, J = 4 Hz), 6.71 (s, 1H), 4.66 (s, 2H), 2.59 (s, 3H);HRMS: C18H13Cl3FN3O requires M + H at m/z 412.0186; found,412.0184; tR = 0.61 min, 97.4% purity.

Methyl 6-Bromo-4-hydroxy-2-methylquinoline-8-carboxy-late (5c).

A mixture of methyl 2-amino-5-bromobenzoate (25.03 g, 109 mmol),methyl acetoacetate (23.5 mL, 218 mmol), and polyphosphoric acid(76.20 g) was heated at 160 °C overnight and then cooled to roomtemperature. Water (400 mL) was added, and the mixture was swirledvigorously until the solid lump dissolved. The resulting mixture wasextracted with methylene chloride (5×). The combined organics weredried over sodium sulfate and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (3:2to 9:1) to provide methyl 6-bromo-4-hydroxy-2-methylquinoline-8-carboxylate 5c (5.28 g, 17.83 mmol, 16% yield) as a yellow solid.1H NMR (400 MHz, CD3SOCD3): δ 11.16 (br s, 1H), 8.39 (d, 1H,J = 2 Hz), 8.32 (d, 1H, J = 2 Hz), 6.13−6.04 (m, 1H), 3.97 (s, 3H),2.43 (s, 3H).

Methyl 6-Bromo-4-chloro-2-methyl-8-quinolinecarboxylate (2c).

Methyl 6-bromo-4-hydroxy-2-methylquinoline-8-carboxylate 5c(5.28 g, 17.28 mmol) and phosphorus oxychloride (17.0 mL,182 mmol) were heated at 80 °C for 60 min and cooled to roomtemperature. Ice was carefully added with external cooling. After allof the phosphorus oxychloride had been hydrolyzed, water (50 mL)was added. The mixture was basicified with 5 N aqueous sodiumhydroxide to pH 8 and extracted with ethyl acetate (4×). Thecombined organics were dried over magnesium sulfate andconcentrated. The residue was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (1:19 to 1:4) to provide methyl6-bromo-4-chloro-2-methyl-8-quinolinecarboxylate 2c (2.38 g, 7.57mmol, 42% yield) as a tan solid. 1H NMR (400 MHz, CDCl3): δ8.45 (d, 1H, J = 2 Hz), 8.04 (d, 1H, J = 2 Hz), 7.45 (s, 1H), 4.04 (s,3H), 2.72 (s, 3H).

Methyl 4-Chloro-2,6-dimethyl-8-quinolinecarboxylate (2d).

Methyl 6-bromo-4-chloro-2-methyl-8-quinolinecarboxylate 2c(0.2497 g, 0.794 mmol) and potassium methyltrifluoroborate(0.1059 g, 0.868 mmol) were dissolved in tetrahydrofuran (8 mL)in a pressure tube (at this point, cesium fluoride was mistakenly added).Cesium carbonate (0.7888 g, 2.421 mmol) was added followed by [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichlorome-thane adduct (0.0638 g, 0.078 mmol). The tube was sealed, and themixture was heated at 85 °C overnight and then cooled to roomtemperature. Water (50 mL) and brine (25 mL) were added, and themixture was extracted with diethyl ether (3×). The combined organicswere dried over magnesium sulfate, filtered, and concentrated. Theresidue was purified by silica gel chromatography, eluting with ethylacetate/hexanes (1:19 to 1:4) to provide methyl 4-chloro-2,6-dimethyl-8-quinolinecarboxylate 2d (0.1320 g, 0.529 mmol, 67%yield) as a white solid. 1H NMR (400 MHz, CDCl3): δ 8.11−8.04 (m,1H), 7.83 (d, 1H, J = 2 Hz), 7.39 (s, 1H), 4.04 (s, 3H), 2.71 (s, 3H),2.57 (s, 3H).



7051


4-Chloro-2,6-dimethyl-8-quinolinecarboxamide (2e).

Methyl 4-chloro-2,6-dimethyl-8-quinolinecarboxylate 2d (0.1320 g,0.529 mmol) was suspended in 2 M ammonia in methanol (5.0 mL) ina sealed tube. The mixture was heated at 100 °C overnight and cooledto room temperature. A solid began to precipitate out of solution, andthe mixture was cooled further to 0 °C. The solid was collected byfiltration and washed with cold methanol to provide 4-chloro-2,6-dimethyl-8-quinolinecarboxamide 2e (0.0464 g, 0.198 mmol, 37%yield) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 10.12(br s, 1H), 8.44 (d, 1H, J = 2 Hz), 8.14 (dd, 1H, J = 2, 1 Hz), 7.92(br s, 1H), 7.80 (s, 1H), 2.71 (s, 3H), 2.58 (s, 3H).4-{[(2,6-Dimethylphenyl)methyl]amino}-2,6-dimethyl-8-qui-

nolinecarboxamide (1bg).

4-Chloro-2,6-dimethyl-8-quinolinecarboxamide 2e (0.0464 g, 0.198 mmol)was suspended in dimethyl sulfoxide (1 mL) in a pressure tube.2,6-Dimethylbenzylamine (0.040 mL, 0.287 mmol) was added,followed by N,N-diisopropylethylamine (0.070 mL, 0.401 mmol).The tube was sealed, and the mixture was heated at 140 °C and thencooled to room temperature. Water (25 mL) was added, and the solidwas collected by filtration. The residue was purified by silica gelchromatography, eluting with ethyl acetate/hexanes (1:6 to 4:1) toprovide 4-{[(2,6-dimethylphenyl)methyl]amino}-2,6-dimethyl-8-qui-nolinecarboxamide 1bg (0.0239 g, 0.072 mmol, 36% yield) as ayellow solid. 1H NMR (400 MHz, CD3SOCD3): δ 11.22 (br s, 1H),8.37−8.26 (m, 2H), 7.66 (br s, 1H), 7.21−7.13 (m, 1H), 7.11 (s, 2H),6.98 (br s, 1H), 6.63 (s, 1H), 4.36 (d, 2H, J = 4 Hz), 2.56 (s, 3H), 2.42(s, 3H), 2.34 (s, 6H); HRMS: C21H23N3O requires M + H at m/z334.1919; found, 334.1909; tR = 0.69 min, 79.1% purity.6-Bromo-4-chloro-2-methylquinoline-8-carboxamide (2f).

Methyl 6-bromo-4-chloro-2-methyl-8-quinolinecarboxylate 2c (0.6031 g1.917 mmol) was dissolved in 2 M ammonia in methanol (30 mL) in apressure flask. The flask was sealed, and the mixture was heated at 100 °Cfor 3 h and cooled to room temperature. The precipitated solid wascollected by filtration to provide 6-bromo-4-chloro-2-methylquinoline-8-carboxamide 2f (0.2293 g, 0.765 mmol, 40% yield) as a yellow solid. 1HNMR (400 MHz, CD3SOCD3): δ 9.88 (br s, 1H), 8.55 (d, 1H, J =2 Hz), 8.48 (d, 1H, J = 2 Hz), 8.09 (br s, 1H), 7.91 (s, 1H), 2.72 (s, 3H).6-Bromo-4-((2,6-dimethylbenzyl)amino)-2-methylquinoline-

8-carboxamide (1bh).

6-Bromo-4-chloro-2-methyl-8-quinolinecarboxamide 2f (0.2293 g,0.765 mmol) was suspended in dimethyl sulfoxide (4 mL) in apressure tube. 2,6-Dimethylbenzyl amine (0.150 mL, 1.076 mmol) andN,N-diisopropylethylamine (0.270 mL, 1.546 mmol) were added, thetube was sealed, and the mixture was heated at 140 °C for 20 h andthen cooled to room temperature. Water (100 mL) was added, and thesolid was collected by filtration. The residue was purified by silica gelchromatography, eluting with ethyl acetate/hexanes (1:9 to 1:3) toprovide 6-bromo-4-((2,6-dimethylbenzyl)amino)-2-methylquinoline-8-carboxamide 1bh (0.1986 g, 0.499 mmol, 65% yield) as a paleyellow solid. 1H NMR (400 MHz, CDC13): δ 11.71 (br s, 1H), 8.80(d, 1H, J = 2 Hz), 7.86 (d, 1H, J = 2 Hz), 7.26−7.20 (m, 1H), 7.19−7.08 (m, 2H), 6.55 (s, 1H), 6.17−6.05 (m, 1H), 4.66 (br s, 1H), 4.40(d, 2H, J = 4 Hz), 2.67 (s, 3H), 2.41 (s, 6H); HRMS: C20H20BrN3Orequires M + H at m/z 398.0868; found, 398.0870; tR = 0.66 min,92.8% purity.

4-Chloro-2-methyl-6-phenyl-8-quinolinecarboxamide (2g).

6-Bromo-4-chloro-2-methyl-8-quinolinecarboxamide 2f (0.2024 g,0.676 mmol) was dissolved in tetrahydrofuran (1.5 mL). Phenyl-boronic acid (0.0896 g, 0.735 mmol) was added, followed by 2 Maqueous potassium carbonate (0.670 mL, 1.34 mmol) and bis-(triphenylphosphine)palladium(II) chloride (0.0266 g, 0.038 mmol).The resulting mixture was heated at 80 °C for 60 min, cooled to roomtemperature, and stirred overnight. Brine (25 mL) and water (25 mL)were added, and the mixture was extracted with ethyl acetate (3×).The combined organics were dried over magnesium sulfate, filtered,and concentrated. The residue was purified by silica gel chromatog-raphy, eluting with ethyl acetate/hexanes (3:7 to 9:11) to provide4-chloro-2-methyl-6-phenyl-8-quinolinecarboxamide 2g (0.0907 g,0.306 mmol, 45% yield) as a pale yellow solid. 1H NMR (400 MHz,CD3SOCD3): δ 10.10 (d, 1H, J = 3 Hz), 8.87 (d, 1H J = 2 Hz), 8.51(d, 1H, J = 2 Hz), 8.05 (d, 1H, J = 3 Hz), 7.92−7.81 (m, 3H), 7.67−7.53 (m, 2H), 7.53−7.44 (m, 1H), 2.76 (s, 3H).

4-{[(2,6-Dimethylphenyl)methyl]amino}-2-methyl-6-phenyl-8-quinolinecarboxamide (1bi).

4-Chloro-2-methyl-6-phenyl-8-quinolinecarboxamide 2g (0.1611 g,0.543 mmol) was suspended in dimethyl sulfoxide (4 mL) in apressure tube. 2,6-Dimethylbenzylamine (0.110 mL, 0.789 mmol) wasadded, followed by N,N-diisopropylethylamine (0.190 mL, 1.086mmol). The tube was sealed, and the mixture was heated at 140 °Covernight and then cooled to room temperature. Water (25 mL) wasadded, and the solid was collected by filtration and dried. The materialwas triturated with ethanol and filtered. The solid was purified by silicagel chromatography (2:3 to 7:3 ethyl acetate/hexanes). The resultingresidue was recrystallized from ethyl acetate to provide 4-{[(2,6-dimethylphenyl)methyl]amino}-2-methyl-6-phenyl-8-quinolinecarbox-amide 1bi (0.0092 g, 0.023 mmol, 4.3% yield) as a white solid. 1HNMR (400 MHz, CD3SOCD3): δ 11.23 (br s, 1H), 8.76 (d, 2H, J =9 Hz), 7.84−7.76 (m, 3H), 7.49 (t, 2H, J = 8 Hz), 7.44−7.34 (m, 2H),7.16 (d, 1H, J = 7 Hz), 7.14−7.07 (m, 2H), 6.71 (s, 1H), 4.41 (d, 2H,J = 5 Hz), 2.60 (s, 3H), 2.36 (s, 6H); HRMS: C26H25N3O requiresM + H at m/z 396.2076; found, 396.2072; tR = 0.82 min, 91.4% purity.



7052


N-[(2,3-Dichlorophenyl)methyl]-2-methyl-4-quinolinamine(1bj).

4,4,4′,4′,5,5,5′,5′-Octamethyl-2,2′-bi-1,3,2-dioxaborolane (0.160 g,0.629 mmol) was added to 8-bromo-N-[(2,3-dichlorophenyl)-methyl]-2-methyl-4-quinolinamine 1bk (0.1661 g, 0.419 mmol) in1,4-dioxane (8.39 mL) under nitrogen at room temperature. Then,potassium acetate (0.185 g, 1.887 mmol) was added, followed byPdCl2(dppf) (0.015 g, 0.021 mmol), and the reaction was evacuated,purged with nitrogen, heated at 80 °C, and stirred for 16 h. The reactionmixture was filtered through Celite and concentrated, and the cruderesidue was purified via column chromatography, eluting with methanol/ethyl acetate (1:4) to give the debromonated product N-[(2,3-dichloro-phenyl)methyl]-2-methyl-4-quinolinamine 1bj (0.0624 g, 0.187 mmol,45% yield) instead of the desired boronate ester. 1H NMR (400 MHz,CD3SOCD3): δ 8.22 (d, 1H, J = 8 Hz), 7.77 (br t, 1H, J = 6 Hz), 7.71 (d,1H, J = 8 Hz), 7.59 (t, 1H, J = 7 Hz), 7.56 (d, 1H, J = 8 Hz), 7.40 (t, 1H,J = 8 Hz), 7.30 (t, 1H, J = 8 Hz), 7.25 (d, 1H, J = 7 Hz), 6.18 (s, 1H),4.61 (d, 2H, J = 6 Hz), 2.36 (s, 3H); HRMS: C17H14Cl2N2 requiresM + H at m/z 317.0612; found, 317.0593; tR = 0.63 min, 100.0% purity.8-Bromo-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quino-

linamine (1bk).

N,N-Diisopropylethylamine (2.104 mL, 12.05 mmol) was added to8-bromo-4-chloro-2-methylquinoline 2a (1.03 g, 4.02 mmol) indimethyl sulfoxide (8.03 mL) at room temperature, followed by[(2,3-dichlorophenyl)methyl]amine (0.803 mL, 6.02 mmol), and thesolution was heated at 140 °C and stirred for 68 h. The reactionmixture was cooled, poured into ether, washed with water, dried overmagnesium sulfate, filtered, and concentrated. The residue was purifiedby silica gel chromatography, eluting with ethyl acetate/hexanes (1:4) togive 8-bromo-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quinolinamine1bk (1.26 g, 3.02 mmol, 75% yield). 1H NMR (400 MHz, CD3SOCD3):δ 8.26 (d, 1H, J = 8 Hz), 7.97 (d, 1H, J = 7 Hz), 7.89 (br t, 1H, J =6 Hz), 7.57 (dd, 1H, J = 8, 2 Hz), 7.31 (dd, 1H, J = 8, 2 Hz), 7.29 (dd,1H, J = 8, 2 Hz), 7.24 (dd, 1H, J = 7, 1 Hz), 6.29 (s, 1H), 4.62 (d, 2H,J = 6 Hz), 2.41 (s, 3H); HRMS: C17H13BrCl2N2 requires M + H at m/z394.9717; found, 394.9703; tR = 0.77 min, 92.0% purity.4-{[(2,3-Dichlorophenyl)methyl]amino}-N,2-dimethyl-8-qui-

nolinecarboxamide (1bl).

N,N-Diisopropylethylamine (0.076 mL, 0.434 mmol) and methyl-amine (0.690 mL, 1.380 mmol) were added to 8-bromo-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quinolinamine 1bk (0.0781 g,0.197 mmol) in N,N-dimethylformamide (3.18 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.024 g,

0.059 mmol) and palladium(II) acetate (8.85 mg, 0.039 mmol), and thesolution was fitted with a carbon monoxide balloon, heated at 110 °C, andstirred for 4 h. The reaction mixture was cooled, poured into ether, washedwith 1 N sodium hydroxide and water, dried over magnesium sulfate,filtered, and concentrated. The residue was purified by silica gelchromatography, eluting with ethyl acetate to give 4-{[(2,3-dichlorophenyl)-methyl]amino}-N,2-dimethyl-8-quinolinecarboxamide 1bl (0.0466 g, 0.118mmol, 60% yield). 1H NMR (400 MHz, CD3SOCD3): δ 11.69 (br q, 1H,J = 5 Hz), 8.51 (d, 1H, J = 7 Hz), 8.44 (d, 1H, J = 8 Hz), 8.06 (br t, 1H,J = 6 Hz), 7.58 (d, 1H, J = 8 Hz), 7.51 (t, 1H, J = 8 Hz), 7.31 (t, 1H, J =8 Hz), 7.26 (d, 1H, J = 7 Hz), 6.33 (s, 1H), 4.65 (d, 2H, J = 6 Hz), 2.93 (d,3H, J = 5 Hz), 2.47 (s, 3H); HRMS: C19H17Cl2N3O requires M + H atm/z 374.0827; found, 374.0821; tR = 0.65 min, 100.0% purity.

4-{[(2,3-Dichlorophenyl)methyl]amino}-N,N,2-trimethyl-8-quinolinecarboxamide (1bm).

N,N-Diisopropylethylamine (0.080 mL, 0.460 mmol) and dimethylamine(0.733 mL, 1.465 mmol) were added to 8-bromo-N-[(2,3-dichlorophenyl)-methyl]-2-methyl-4-quinolinamine 1bk (0.0829 g, 0.209 mmol) in N,N-dimethylformamide (3.37 mL) at room temperature, followed by 1,3-bis(diphenylphosphino)propane (0.026 g, 0.063 mmol) and palladium(II)acetate (9.40 mg, 0.042 mmol), and the solution was fitted with a carbonmonoxide balloon, heated at 110 °C, and stirred for 4 h. The reactionmixture was cooled, poured into ether, washed with 1 N sodium hydroxideand water, dried over magnesium sulfate, filtered, and concentrated. Theresidue was purified by silica gel chromatography, eluting with methanol/ethyl acetate (1:19) to give 4-{[(2,3-dichlorophenyl)methyl]amino}-N,N,2-trimethyl-8-quinolinecarboxamide 1bm (0.0399 g, 0.098 mmol, 47% yield).1H NMR (400 MHz, CD3SOCD3): δ 8.25 (d, 1H, J = 8 Hz), 7.82 (br t,1H, J = 6 Hz), 7.57 (d, 1H, J = 7 Hz), 7.45 (d, 1H, J = 7 Hz), 7.41 (t, 1H,J = 8 Hz), 7.31 (t, 1H, J = 8 Hz), 7.27 (t, 1H, J = 7 Hz), 6.22 (s, 1H), 4.62(d, 2H, J = 6 Hz), 2.88 (s, 3H), 2.63 (s, 3H), 2.34 (s, 3H); HRMS:C20H19Cl2N3O requires M + H at m/z 388.0983; found, 388.0970; tR =0.60 min, 100.0% purity.

Methyl 4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxylate (1bn).

N,N-Diisopropylethylamine (0.212 mL, 1.215 mmol) and methanol(0.447 mL, 11.04 mmol) were added to 8-bromo-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quinolinamine 1bk (0.2187 g,0.552 mmol) in N,N-dimethylformamide (10.38 mL) at room tem-perature, followed by 1,3-bis(diphenylphosphino)propane (0.068 g,0.166 mmol) and palladium(II) acetate (0.025 g, 0.110 mmol), andthe solution was fitted with a carbon monoxide balloon, heated at110 °C, and stirred for 2 h. The reaction mixture was cooled, pouredinto ether, washed with saturated sodium bicarbonate and water, driedover magnesium sulfate, filtered, and concentrated. The residue waspurified by silica gel chromatography, eluting with methanol/ethylacetate (1:4) to give methyl 4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxylate 1bn (0.1446 g, 0.366 mmol,66% yield). 1H NMR (400 MHz, CD3SOCD3): δ 8.35 (d, 1H, J =8 Hz), 7.86 (br s, 1H), 7.69 (d, 1H, J = 7 Hz), 7.57 (d, 1H, J = 8 Hz),



7053


7.43 (t, 1H, J = 8 Hz), 7.30 (t, 1H, J = 8 Hz), 7.25 (d, 1H, J = 7 Hz),6.25 (s, 1H), 4.62 (d, 2H, J = 5 Hz), 3.84 (s, 3H), 2.35 (s, 3H);HRMS: C19H16Cl2N2O2 requires M + H at m/z 375.0667; found,375.0667; tR = 0.68 min, 100.0% purity.4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-quinoli-

necarboxylic acid (1bo).

Lithium hydroxide (3.91 mg, 0.163 mmol) was added to methyl4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxylate1bn (0.0438 g, 0.117 mmol) in tetrahydrofuran (0.778 mL), methanol(0.778 mL), and water (0.778 mL), and the reaction mixture was stirred for18 h at room temperature. After concentration, the residue was purifiedby reverse-phase column chromatography, eluting with acetonitrile/water(25:75 to 100:0) with 0.1% trifluoroacetic acid to give 4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxylic acid 1bo(0.0331 g, 0.066 mmol, 57% yield). 1H NMR (400 MHz, CD3SOCD3):δ 9.45 (br s, 1H), 8.74 (d, 1H, J = 8 Hz), 8.57 (d, 1H, J = 8 Hz), 7.77 (t,1H, J = 8 Hz), 7.64 (dd, 1H, J = 8, 4 Hz), 7.40−7.32 (m, 2H), 6.82 (s, 1H),4.84 (d, 2H, J = 6 Hz), 2.66 (s, 3H); HRMS: C18H14Cl2N2O2 requiresM + H at m/z 361.0510; found, 361.0507; tR = 0.66 min, 100.0% purity.(4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-

quinolinyl)methanol (1bp).

Lithium borohydride (0.121 mL, 0.241 mmol) was added to methyl4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxy-late 1bn (0.0905 g, 0.241 mmol) in tetrahydrofuran (2.291 mL) at0 °C, and the solution was allowed to warm to room temperature andstirred for 2 h. The reaction mixture was quenched with methanol andthen water, and the reaction mixture was extracted with diethyl ether,dried over magnesium sulfate, filtered, and concentrated. The residuewas purified by silica gel chromatography, eluting with ethyl acetate to give(4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinyl)methanol1bp (0.0564 g, 0.154 mmol, 64% yield). 1H NMR (400 MHz,CD3SOCD3): δ 8.11 (d, 1H, J = 8 Hz), 7.75 (br t, 1H, J = 6 Hz), 7.64(d, 1H, J = 7 Hz), 7.56 (d, 1H, J = 8 Hz), 7.38 (t, 1H, J = 8 Hz), 7.29 (t,1H, J = 8 Hz), 7.24 (d, 1H, J = 8 Hz), 6.20 (s, 1H), 5.32 (br s, 1H), 5.00 (s,2H), 4.61 (d, 2H, J = 6 Hz), 2.37 (s, 3H); HRMS: C18H16Cl2N2O requiresM + H at m/z 347.0718; found, 347.0716; tR = 0.72 min, 96.6% purity.8-(Aminomethyl)-N-[(2,3-dichlorophenyl)methyl]-2-methyl-

4-quinolinamine (1bq).

Methane sulfonic anhydride (0.024 g, 0.137 mmol) was added to (4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinyl)-methanol 1bp (0.0397 g, 0.114 mmol) in tetrahydrofuran (3.48 mL) atroom temperature. Then, the reaction mixture was stirred for 41 h at

room temperature. Then, ammonia (0.327 mL, 2.287 mmol) was added,and the reaction was stirred for 17 h at room temperature. The reactionmixture was concentrated. The residue was purified by reverse-phase high-performance liquid chromatography, eluting with water/acetonitrile with0.05% trifluoroacetic acid (1:3 to 0:1) to give 8-(aminomethyl)-N-[(2,3-dichlorophenyl)methyl]-2-methyl-4-quinolinamine bis(trifluoroacetate)1bq (0.0197 g, 0.033 mmol, 29% yield). 1H NMR (400 MHz,CD3SOCD3): δ 12.70 (br s, 1H), 9.64 (br s, 1H), 8.57 (d, 1H, J =6 Hz), 8.41 (br s, 3H), 8.02 (s, 1H), 7.76 (s, 1H), 7.64 (d, 1H, J = 7 Hz),7.35 (t, 1H, J = 8 Hz), 7.29 (d, 1H, J = 7 Hz), 6.85 (s, 1H), 4.86 (s, 2H),4.61 (s, 2H), 2.67 (s, 3H); HRMS: C18H17Cl2N3 requires M + H at m/z346.0878; found, 346.0870; tR = 0.46 min, 100.0% purity.

4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-quinoli-necarbonitrile (1br).

Belleau’s Reagent (2,4-bis[4-(phenyloxy)phenyl]-1,3,2,4-dithiadiphos-phetane 2,4-disulfide) (0.366 g, 0.693 mmol) was added to 4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide 1q(0.0832 g, 0.231 mmol) in 1,4-dioxane (4.62 mL) at room temperature,and the reaction mixture was heated at reflux for 16 h. The reaction mixturewas cooled, and the solution was purified by silica gel chromatography,eluting with ethyl acetate/hexanes (2:3) to give an impure mixture that wasfurther purified by reverse -phase high-performance liquid chromatography,eluting with acetonitrile/water (1:3 to 3:1) to give 4-{[(2,3-dichlorophenyl)methyl]amino}-2-methyl-8-quinolinecarbonitrile 1br(0.0237 g, 0.066 mmol, 28% yield) instead of the thioamide. 1H NMR(400 MHz, CD3SOCD3): δ 8.56 (d, 1H, J = 8 Hz), 8.16 (d, 1H, J = 8 Hz),8.07 (br t, 1H, J = 6 Hz), 7.58 (d, 1H, J = 8 Hz), 7.52 (t, 1H, J = 8 Hz),7.31 (t, 1H, J = 6 Hz), 7.27 (d, 1H, J = 7 Hz), 6.37 (s, 1H), 4.63 (d, 2H, J =6 Hz), 2.44 (s, 3H); HRMS: C18H13Cl2N3 requires M + H at m/z342.0565; found, 342.0554; tR = 0.74 min, 94.6% purity.

4-Chloro-2-methyl-8-quinolinesulfonamide (2h).

4-Chloro-2-methyl-8-quinolinesulfonyl chloride 2h19 (34 mg, 0.123 mmol)was placed in a reaction vial and dissolved in 0.5 M ammonia in dioxane(3 mL, 1.50 mmol). The reaction vial was sealed, and the mixture washeated at 60 °C while stirring for 1 h. A white precipitate formed duringthe reaction. After cooling to room temperature, the mixture wasevaporated to dryness. The remaining solid was triturated with hexane,collected by vacuum filtration, washed with water, and dried in vacuo togive 4-chloro-2-methyl-8-quinolinesulfonamide 2i (26 mg, 0.101 mmol,82%) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 8.42 (dd, 1H,J = 8, 1 Hz), 8.36 (dd, 1H, J = 7, 1 Hz), 7.89 (s, 1H), 7.81 (t, 1H, J =8 Hz), 7.24 (s, 2H), 2.77 (s, 3H); LC-MS (LC-ES) M + H = 257.

4-{[(2,3-Dichlorophenyl)methyl]amino}-2-methyl-8-quinoli-nesulfonamide (1bs).



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4-Chloro-2-methyl-8-quinolinesulfonamide 2i (23.5 mg, 0.092 mmol)was placed in a reaction vial and dissolved in N-methylpyrrolidinone(0.5 mL). 2,3-Dichlorobenzylamine (33 mg, 0.188 mmol) was addedto the mixture. The vial was sealed, and the mixture was heated at150 °C while stirring overnight. After cooling to room temperature,the mixture was diluted with ethyl acetate, washed with saturatedaqueous sodium bicarbonate, dried over sodium sulfate, and filtered.The filtrate was evaporated onto silica gel and chromatographed onsilica gel, eluting with ethyl acetate/hexanes (1:4 to 9:1) to giveimpure product. This material was further purified by reverse-phasehigh-performance liquid chromatography, eluting with a acetonitrile/water with 0.1% trifluoroacetic acid (3:7 to 1:0), and concentrated.The remaining material was dissolved in ethyl acetate, washed with1 N aqueous sodium hydroxide and brine, dried over sodium sulfate,filtered, and concentrated to give 4-{[(2,3-dichlorophenyl)methyl]-amino}-2-methyl-8-quinolinesulfonamide 1bs (17 mg, 0.0429 mmol,47%) as a white solid. 1H NMR (400 MHz, CD3SOCD3): δ 8.53 (d,1H, J = 8 Hz), 8.16 (d, 1H, J = 7 Hz), 8.11 (t, 1H, J = 6 Hz), 7.58 (dd,1H, J = 8, 1 Hz), 7.54 (t, 1H, J = 8 Hz), 7.35−7.29 (m, 1H), 7.27−7.22 (m, 3H), 6.38 (s, 1H), 4.66 (d, 2H, J = 5.5 Hz), 2.47 (s, 3H);HRMS: C17H15Cl2N3O2S requires M + H at m/z 396.0340; found,396.0343; tR = 0.59 min, 95.3% purity.Biochemical Assay Details for the pIC50 Determinations

against the Human CD38 Enzyme. CD38 inhibitors were testedfor their capacity to inhibit human CD38 enzyme activity in acolorimetric-based assay.24 The extracellular domain of human CD38was expressed in Pichia pastoris and purified to homogeneity. Theenzyme activity assay was performed in a low-volume 384-well plate ina total volume of 20 μL. A range of concentrations of test compoundin 200 nL of dimethyl sulfoxide was delivered into the assay platewells. Columns 6 and 18 of the plate contained dimethyl sulfoxide withno compound and served as the high and low signal controls(no CD38 added), respectively. All additions of assay reagents to theplate were done using a Multidrop Combi, and the plate was shaken3−5 s after each addition. CD38 (0.8 nM) was incubated with testcompound in 10 μL containing 100 mM HEPES, pH 7.4, 4 mMEDTA, and 1 mM CHAPS for 30 min prior to initiation of thereaction. The reaction was initiated by a 10 μL addition containing5 mM sodium acetate, pH 4.5, 1 mM CHAPS, 200 μM NAD, and500 μM GW323424X. The solutions for each of the two additionswere prepared fresh each day from concentrated stocks of theindividual components. The final concentrations in the assay were50 mM HEPES, 2 mM EDTA, 1 mM CHAPS, 2.5 mM sodiumacetate, 100 μM NAD, 250 μM GW323434X, and 0.4 nM CD38.GW323434X is a 4-pyridynal compound that acts as a nucleophile thatparticipates in the base exchange reaction with the nicotinamide onNAD to form a novel dinucleotide that absorbs at 405 nm. Catalyticformation of this novel chromophore was followed in an Envisionmicroplate reader by reading absorbance at two time points, typically30 min apart within the first 45 min of the reaction. These time pointswere established empirically to ensure the rates determined were in alinear range of product formation. Data analysis was performed in thefollowing way using Abase XE. The data from the 15 and 45 min readswas processed by performing a subtraction function of 45 min readvalue minus 15 min read value for each plate well. The resulting valuesfor noncontrol wells were converted to percent inhibition using theformula 100 × ((U − C1)/(C2 − C1)), where U is the value of thetest well, C1 is the average of the values of the high signal (column 6)control wells, and C2 is the average of the values of the low signal(column 18) control wells. Percent inhibition (y) was plotted versusinhibitor concentration (x), and curve fitting was performed with thefollowing four-parameter equation: y = A + ((B − A)/(1 + (10x/10C)D)),where A is the minimum response, B is the maximum response, C is thelog10 IC50, and D is the Hill slope. The results for each compound wererecorded as pIC50 values (−C in the above equation).Crystallization Conditions for Mutated Human CD38 (E226Q)

Complexed with 4-{[(2,6-Dimethylphenyl)methyl]amino}-2-methyl-8-quinolinecarboxamide (1a) and ADP-Ribose (ADPR)(PDP Code 4XJT). Apo human CD38 (E226Q) protein was con-centrated to 7 mg/mL. 5 mM NADP was added 1 h prior to setting up

trays. Crystals were grown by hanging drop vapor diffusion in 24-wellLinbro trays from 23% PEG3350, 0.1 M BTP, pH 8.5, at 22 °C (2 + 2 μLdrops over a 500 μL well). After allowing the crystals to grow for severaldays, they were soaked with 5 mM 4-{[(2,6-dimethylphenyl)methyl]-amino}-2-methyl-8-quinolinecarboxamide 1a for 1 day. Prior to datacollection, crystals were flash frozen in paraffin oil.

Crystallization Conditions for Wild-Type Human CD38Complexed with 6-Fluoro-2-methyl-4-((2,3,6-trichlorobenzyl)-amino)quinoline-8-carboxamide (1bf) and the OxoniumRemnant of (2S,3R,4R)-2-Deoxy-2-fluoro-D-ribose 5-Phosphate(FR5P) (PDP Code 4XJS). Apo human CD38 protein was con-centrated to ∼7 mg/mL. Crystals were grown in 24-well hanging dropLinbro plates from 23% PEG3350, 0.1 mM BTP, pH 8.5, at 22 °C (2 +2 μL drops over a 500 μL well). Crystals were soaked with ∼5 mM6-fluoro-2-methyl-4-((2,3,6-trichlorobenzyl)amino)quinoline-8-car-boxamide 1bf and ∼5 mM FR5P for 1 day. Prior to data collection,crystals were flash frozen in paraffin oil.

NAD Tissue Extraction and Analysis Procedure. All studieswere conducted in accordance with the GSK Policy on the Care,Welfare and Treatment of Laboratory Animals and were reviewed bythe Institutional Animal Care and Use Committee either at GSK or bythe ethical review process at the institution where the work wasperformed. All samples were snap frozen in liquid nitrogen tominimize the degradation on NAD before sample analysis. Sampleswere diluted 1:4 with 80:20 acetonitrile/water that contained 18Olabeled NAD and a CD38 inhibitor to be used as an internal standard.Tissue were then homogenized in a bead beater with metal beads andthen centrifuged. The sample extract was diluted 1:10 with water andinjected on Zorbax Hillic Plus C18 column, monitoring the 664−428transition for NAD+ and 668−136 for 18O NAD internal standard.The samples were injected on a C18 using reverse-phase chromatographyto obtain the relevant drug concentration and understand drug distribu-tion in different tissues.

■ AUTHOR INFORMATIONCorresponding Author*Phone: 919-483-6270. E-mail: [email protected] authors declare no competing financial interest.

■ ACKNOWLEDGMENTSThe authors would like to thank the following chemists atChemPartners CRO for synthetic assistance: C. Chuantao, L.Huifeng, W. Lu, D. Qiu, S. Ran, Z. Tao, Y. Wei, H. Xiao, C.Yanyan, L. Yuanxin, Z. Yunpeng, H. Zeng, and L. Zhichao. Theauthors would also like to thank Iris V. Paulus for high-resolution mass determinations and Yingnian Shen, DavidTaylor, Jamey Christie, Scott Sigethy, Angela Rauer, GeorgeBarrett, Tim Broderick, Luke Carter, and Kurt Weaver for thecloning, expression, and purification of the CD38 protein thatwas used in the biochemical assays.

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