ORGANIC SUBSTITUENT GROUPS AND RING SYSTEMS

The first part of this table lists substituent groups and their line formulas. A substituent group is defined by IUPAC as a group that replaces one or more hydrogen atoms attached to a parent structure. Such groups are sometimes called radicals, but IUPAC now reserves the term radical for a free molecular species with unpaired electrons. IUPAC does not recommend some of these names, which are marked here with asterisks (e.g., amyl*), but they are included in this list because they are often encountered in the older literature. Substituent group names which are formed

by systematic rules (e.g., methyl from methane, ethyl from ethane, etc.) are included here only for the first few members of a homolo-gous series.

In the second part of the table a number of common organic ring compounds are shown, with the conventional numbering of the ring positions indicated.

The help of Warren H. Powell in preparing this table is great-ly appreciated. Pertinent references may be found in the table “Nomenclature of Chemical Compounds.”

acetamido (acetylamino) CH3CONH-acetoacetyl CH3COCH2CO-acetonyl CH3COCH2-acetyl CH3CO-acryloyl* (1-oxo-2-propenyl) CH2=CHCO-alanyl (from alanine) CH3CH(NH2)CO-β-alanyl H2N(CH2)2CO-allyl (2-propenyl) CH2=CHCH2-allylidene (2-propenylidene) CH2=CHCH=amidino (aminoiminomethyl) H2NC(=NH)-amino H2N-amyl* (pentyl) CH3(CH2)4-anilino (phenylamino) C6H5NH-anisidino CH3OC6H4NH-anthranoyl (2-aminobenzoyl) 2-H2NC6H4CO-arsino AsH2-azelaoyl (from azelaic acid) -OC(CH2)7CO-azido N3-azino =N-N=azo -N=N-azoxy -N(O)=N-benzal* (benzylidene) C6H5CH=benzamido (benzoylamino) C6H5CONH-benzhydryl (diphenylmethyl) (C6H5)2CH-benzoxy* (benzoyloxy) C6H5COO-benzoyl C6H5CO-benzyl C6H5CH2-benzylidene C6H5CH=benzylidyne C6H5C=biphenylyl C6H5C6H5-biphenylene -C6H4-C6H4-butoxy C4H9O-sec-butoxy (1-methylpropoxy) C2H5CH(CH3)O-tert-butoxy (1,1-dimethylethoxy) (CH3)3CO-butyl CH3(CH2)3-sec-butyl (1-methylpropyl) CH3CH2CH(CH3)-tert-butyl (1,1-dimethylethyl) (CH3)3C-butyryl (1-oxobutyl) CH3(CH2)2CO-caproyl* (hexanoyl) CH3(CH2)4CO-capryl* (decanoyl) CH3(CH2)8CO-capryloyl* (octanoyl) CH3(CH2)6CO-carbamido (carbamoylamino) H2NCONH-carbamoyl (aminocarbonyl) H2NCO-carbamyl (aminocarbonyl) H2NCO-carbazoyl (hydrazinocarbonyl) H2NNHCO-carbethoxy (ethoxycarbonyl) C2H5OCO-carbonyl =C=Ocarboxy HOOC-cetyl* (hexadecyl) CH3(CH2)15-chloroformyl (chlorcarbonyl) ClCO-

cinnamoyl C6H5CH=CHCO-cinnamyl (3-phenyl-2-propenyl) C6H5CH=CHCH2-cinnamylidene C6H5CH=CHCH=cresyl* (hydroxymethylphenyl) HO(CH3)C6H4-crotonoyl CH3CH=CHCO-crotyl (2-butenyl) CH3CH=CHCH2-cyanamido (cyanoamino) NCNH-cyanato NCO-cyano NC-decanedioyl -OC(CH2)8CO-decanoyl CH3(CH2)8CO-diazo N2=diazoamino -NHN=N-disilanyl H3SiSiH2-disiloxanyloxy H3SiOSiH2O-disulfinyl -S(O)S(O)-dithio -SS-enanthoyl* (heptanoyl) CH3(CH2)5CO-epoxy -O-ethenyl (vinyl) CH2=CH-ethynyl HC≡C-ethoxy C2H5O-ethyl CH3CH2-ethylene -CH2CH2-ethylidene CH3CH=ethylthio C2H5S-formamido (formylamino) HCONH-formyl HCO-furmaroyl (from fumaric acid) -OCCH=CHCO-furfuryl (2-furanylmethyl) OC4H3CH2-furfurylidene (2-furanylmethylene) OC4H3CH=glutamoyl (from glutamic acid) -OC(CH2)2CH(NH2)CO-glutaryl (from glutaric acid) -OC(CH2)3CO-glycylamino H2NCH2CONH-glycoloyl; glycolyl (hydroxyacetyl) HOCH2CO-glycyl (aminoacetyl) H2NCH2CO-glyoxyloyl; glyoxylyl (oxoacetyl) HCOCO-guanidino H2NC(=NH)NH-guanyl (aminoiminomethyl) H2NC(=NH)-heptadecanoyl CH3(CH2)15CO-heptanamido CH3(CH2)5CONH-heptanedioyl -OC(CH2)5CO-heptanoyl CH3(CH2)5CO-hexadecanoyl CH3(CH2)14CO-hexamethylene (1,6-hexanediyl) -(CH2)6-hexanedioyl -OC(CH2)4CO-hippuryl (N-benzoylglycyl) C6H5CONHCH2CO-hydrazino H2NNH-hydrazo -HNNH-hydrocinnamoyl C6H5(CH2)2CO-

Substituent Groups

2-16

HC&P_S02.indb 16 5/2/05 2:50:38 PM

hydroperoxy HOO-hydroxyamino HONH-hydroxy HO-imino HN=iodoso* (iodosyl) OI-iodyl O2I-isoamyl* (isopentyl; 3-methylbutyl) (CH3)2CH(CH2)2-isobutenyl (2-methyl-1-propenyl) (CH3)2C=CH-isobutoxy (2-methylpropoxy) (CH3)2CHCH2O-isobutyl (2-methylpropyl) (CH3)2CHCH2-isobutylidene (3-methylpropylidene) (CH3)2CHCH=isobutyryl (2-methyl-1-oxopropyl) (CH3)2CHCO-isocyanato OCN-isocyano CN-isohexyl (4-methylpentyl) (CH3)2CH(CH2)3-isoleucyl (from isoleucine) C2H5CH(CH3)CH(NH2)CO-isonitroso* (hydroxyamino) HON=isopentyl (3-methylbutyl) (CH3)2CH(CH2)2-isopentylidene (3-methylbutylidene) (CH3)2CHCH2CH=isopropenyl (1-methylethenyl) CH2=C(CH3)-isopropoxy (1-methylethoxy) (CH3)2CHO-isopropyl (1-methylethyl) (CH3)2CH-isopropylidene (1-methylethylidene) (CH3)2C=isothiocyanato (isothiocyano) SCN-isovaleryl* (3-methyl-1-oxobutyl) (CH3)2CHCH2CO-lactoyl (from lactic acid) CH3CH(OH)CO-lauroyl (from lauric acid) CH3(CH2)10CO-lauryl (dodecyl) CH3(CH2)11-leucyl (from leucine) (CH3)2CHCH2CH(NH2)CO-levulinoyl (from levulinic acid) CH3CO(CH2)2CO-malonyl (from malonic acid) -OCCH2CO-mandeloyl (from mandelic acid) C6H5CH(OH)CO-mercapto HS-mesityl 2,4,6-(CH3)3C6H2-methacryloyl (from methacrylic acid) CH2=C(CH3)CO-methallyl (2-methyl-2-propenyl) CH2=C(CH3)CH2-methionyl (from methionine) CH3SCH2CH2CH(NH2)CO-methoxy CH3O-methyl H3C-methylene H2C=methylthio CH3S-myristoyl (from myristic acid) CH3(CH2)12CO-myristyl (tetradecyl) CH3(CH2)13-naphthyl (C10H7)-naphthylene -(C10H6)-neopentyl (2,2-dimethylpropyl) (CH3)3CCH2-nitramino (nitroamino) O2NNH-nitro O2N-nitrosamino (nitrosoamino) ONNH-nitrosimino (nitrosoimino) ONN=nitroso ON-nonanoyl (from nonanoic acid) CH3(CH2)7CO-oleoyl (from oleic acid) CH3(CH2)7CH=CH(CH2)7CO-oxalyl (from oxalic acid) -OCCO-oxo O=palmitoyl (from palmitic acid) CH3(CH2)14CO-pentamethylene (1,5-pentanediyl) -(CH2)5-pentyl CH3(CH2)4-tert-pentyl CH3CH2C(CH3)2-phenacyl C6H5COCH2-phenacylidene C6H5COCH=phenethyl (2-phenylethyl) C6H5CH2CH2-phenoxy C6H5O-phenyl C6H5-

phenylene (benzenediyl) -C6H4-phosphino* (phosphanyl) H2P-phosphinyl* (phosphinoyl) H2P(O)-phospho O2P-phosphono (HO)2P(O)-phthaloyl (from phthalic acid) 1,2-C6H4(CO-)2

picryl (2,4,6-trinitrophenyl) 2,4,6-(NO2)3C6H2-pimeloyl (from pimelic acid) -OC(CH2)5CO-piperidino (1-piperidinyl) C5H10N-pivaloyl (from pivalic acid) (CH3)3CCO-prenyl (3-methyl-2-butenyl) (CH3)2C=CHCH2-propargyl (2-propynyl) HC´CCH2-1-propenyl -CH=CHCH2

2-propenyl (allyl) CH2=CHCH2-propionyl* (propanyl) CH3CH2CO-propoxy CH3CH2CH2O-propyl CH3CH2CH2-propylidene CH3CH2CH=pyrryl (pyrrolyl) C3H4N-salicyloyl (2-hydroxybenzoyl) 2-HOC6H4CO-selenyl* (selanyl; hydroseleno) HSe-seryl (from serine) HOCH2CH(NH2)CO-siloxy H3SiO-silyl H3Si-silylene H2Si=sorboyl (from sorbic acid) CH3CH=CHCH=CHCO-stearoyl (from stearic acid) CH3(CH2)14CO-stearyl (octadecyl) CH3(CH2)17-styryl (2-phenylethenyl) C6H5CH=CH-suberoyl (from suberic acid) -OC(CH2)6CO-succinyl (from succinic acid) -OCCH2CH2CO-sulfamino (sulfoamino) HOSO2NH-sulfamoyl (sulfamyl) H2NSO2-sulfanilyl [(4-aminophenyl)sulfonyl] 4-H2NC6H4SO2-sulfeno HOS-sulfhydryl (mercapto) HS-sulfinyl OS=sulfo HO3S-sulfonyl (sulfuryl) -SO2-terephthaloyl 1,4-C6H4(CO-)2

tetramethylene -(CH2)4-thienyl (from thiophene) (C4H3S)-thiocarbonyl (carbothionyl) =CSthiocarboxy HOSC-thiocyanato (thiocyano) NCS-thionyl* (sulfinyl) -SO-threonyl (from threonine) CH3CH(OH)CH(NH2)CO-toluidino [(methylphenyl)amino] CH3C6H4NH-toluoyl (methylbenzoyl) CH3C6H4CO-tolyl (methylphenyl) CH3C6H4-α-tolyl (benzyl) C6H5CH2-tolylene (methylphenylene) -(CH3C6H3)-tosyl [(4-methylphenyl) sulfonyl)] 4-CH3C6H4SO2-triazano H2NNHNH-trimethylene (1,3-propanediyl) -(CH2)3-trityl (triphenylmethyl) (C6H5)3C-valeryl* (pentanoyl) CH3(CH2)3CO-valyl (from valine) (CH3)2CHCH(NH2)CO-vinyl (ethenyl) CH2=CH-vinylidene (ethenylidene) CH2=C=xylidino [(dimethylphenyl)amino] (CH3)2C6H3NH-xylyl (dimethylphenyl) (CH3)2C6H3-xylylene [phenelenebis(methylene)] -CH2C6H4CH2-

Organic Substituent Groups and Ring Systems 2-17

HC&P_S02.indb 17 5/2/05 2:50:39 PM

Cyclopropane

123

Spiropentane

152

34

Cyclobutane

1 234

Cyclopentane

15 2

34

O

Furan

15 234

N

2H-Pyrrole(2H-Azole)

15 2

34N

Pyrrole(Azole)

15 234

HS

Thiophene

15 234

NNN

1,2,3-Triazole

15 234

HN

N2H-Imidazole(1,3-Diazole)

15 2

34

N

3H-Pyrrole(3H-Azole)

15 234

NN

Pyrazole(1,2-Diazole)

15 234

H

N

NN

1,2,4-Triazole

15 234

HS

S

1,2-Dithiole

15 234

S

S1,3-Dithiole

15 234

OS

3H-1,2-Oxathiole

15 234

ON

Isoxazole(1,2-Oxazole)

15 234

SN

Isothiazole(1,2-Thiazole)

15 234

O

NOxazole

(1,3-Oxazole)

15 234

S

NThiazole

(1,3-Thiazole)

15 234

ONN

1,2,3-Oxadiazole

15 234 N

ON

1,2,4-Oxadiazole

15 234

NO

N

1,2,5-Oxadiazole(Furazan)

15 234 N

O

N1,3,4-Oxadiazole

15 234 N

ONN

1,2,3,4-Oxatriazole

15 234

NO

NN

1,2,3,5-Oxatriazole

15 234

OON

3H-1,2,3-Dioxazole

15 234

HN

OO

1,2,4-Dioxazole

15 234

ONO

1,3,2-Dioxazole

15 234

H

N

O

O1,3,4-Dioxazole

15 234

NO

S

5H-1,2,5-Oxathiazole

15 234

H O

S1,3-Oxathiole

15 234

43216

5

O

2H-Pyran

432

165

Benzene

432

165

Cyclohexane

43216

5

O

2H-Pyran-2-one(2-Pyrone)

O

43216

5

O

4H-Pyran-4-one(4-Pyrone)

O

43216

5

O

4H-Pyran

43216

5O

O

1,2-Dioxin

43216

5 O

O

1,3-Dioxin

N1 2

34

56

Pyridine

432

165

NN

Pyridazine

432

165 N

N

Pyrimidine

432

165

N

N

Pyrazine

43216

5

N

N

Piperazine

H

H

43216

5N N

N

1,3,5-Triazine(s-Triazine)

432

165 N

NN

1,2,3-Triazine(v-Triazine)

432

165

N

NN

1,2,4-Triazine(as-Triazine)

43216

5N

O

4H-1,2-Oxazine

43216

5 N

O

2H-1,3-Oxazine

O

N

1 23

456

6H-1,3-Oxazine

ON1 2

34

56

6H-1,2-Oxazine

43216

5

N

O

1,4-Oxazine

43216

5N

O

2H-1,2-Oxazine

H

43216

5

N

O

4H-1,4-Oxazine

H

43216

5NS

O

1,2,5-Oxathiazine

43216

5

N SO

1,2,6-Oxathiazine

43216

5

N

NO

1,2,4-Oxadiazine

43216

5N N

O

1,3,5-Oxadiazine

43216

5

N

O

Morpholine

NH

Azepine

1

5

7 2

34

6

O

Oxepin

1

5

7 2

34

6

S

Thiepin

1

5

7 2

34

6

1

5

7 23

46

NN

4H-1,2-Diazepine

7

456

Indene

32

1 7

456

2H-Indene(Isoindene)

321

7

456

Benzofuran

O

321

7

456

Isobenzofuran

O3

217

456

Benzo[b]thiophene

S

321

7

456

Benzo[c]thiophene

S3

21 7

456

Indole

N

321

H

7

456

3H-Indole

N

321

7

456

1H-Indole

N32

1

N

4

123

Cyclopenta[b]pyridine

76

5O 7

456

Pyrano[3,4-b]-pyrrole

N

321 7

456

Indazole

NN

321

H

7

456

Benzisoxazole(Indoxazene)

ON

321

Organic Ring Compounds

2-18 Organic Substituent Groups and Ring Systems

HC&P_S02.indb 18 5/2/05 2:51:05 PM

8

567

4321

O

4H-1-Benzopyran-4-one(Chromen-4-one)

O

8

567

43

21 O

1H-2-Benzopyran-1-one(Isocoumarin)

O

8

567

4 321 O

3H-2-Benzopyran-1-one(Isochromen-3-one)

O

8

567

4321

N

Quinoline

8

567

432

1 N

Isoquinoline

8

567

4321 N

N

Cinnoline

8

567

4321

N

N

Quinazoline

N8

567

4321

N

1,8-Naphthyridine

N 8

567

4321

N

1,7-NaphthyridineN

8

567

4321

N

1,5-Naphthyridine

N

8

567

4321

N

1,6-Naphthyridine

8

567

4321

N

O

2H-1,3-Benzoxazine

8

567

4321

N

O

2H-1,4-Benzoxazine

8

567

432

1

NO

1H-2,3-Benzoxazine

8

567

432

1

N

O

4H-3,1-Benzoxazine

8

567

4321

N

NO

2H-1,2-Benzoxazine

H8

567

4321

N

O

4H-1,4-Benzoxazine

H

8

567

10

9

Anthracene

123

4 5

876

9

Phenanthrene

1

10

234

789

Phenalene

456

32

18

567

9

Fluorene

123

4

8

567

9N

Carbazole

123

4

H

8

567

10

9

O

Xanthene

123

4

5

876

9

10N

Acridine

432

1 56

1234

Norpinane(Bicyclo[3.1.1]heptane)

7N

N

6

321

4 985

N

N

7H-Purine

7

H

7

456

Benzoxazole

O

N321 7

456

2,1-Benzisoxazole

NO3

21 8

567

432

1

Naphthalene

8

567

43

21

1,2,3,4-Tetra-hydronaphthalene

(Tetralin)

8

56

7

43

21

Octahydronaphthalene(Decalin)

8

567

4321

O

2H-1-Benzopyran(2H-Chromene)

8

567

4321

O

2H-1-Benzopyran-2-one(Coumarin)

O

Steroid ring system

17

6

16

45

123

12

710

98

1314 15

11

R = Nearly always methylR' = Usually methylR'' = Various groupsH

R

H

R''R'

H

H

Organic Substituent Groups and Ring Systems 2-19

HC&P_S02.indb 19 5/2/05 2:51:19 PM