R.A. Heacock and M.E. Mahon- The Chemistry of the "Aminochromes" Part II: The Preparation, Paper Chromatography, and Spectroscopic Properties of Pure Adrenolutin; The Infrared Spectrum
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THE CHEMISTRY OF THE "AMINOCHROMES" PAR T 11. TI-IE PREPARATION, PAPER CHROMATOGRAPIIY, AND SPECTROSCOPIC PROPERTIES O F PURE ADRENOLUTIN; THE INFRARED SPECTRUM OF ADRENOCHROMElS2 ABSTRACT The preparation of adrcnoluti~i monohydrate in pure crystallirie f o r 1 11 has been carried ou t fly the a1l;al in c rearr ange ment of aqlreous solutions of adrcr iochr o~nc , prepared from th e silver oxide oxidntio~l f aclrenali ne in aqueous solution. AII anion-exchange resin (Do wes -l (C1-)) was employeti to renl ove inorganic coutan~inarits roni t he reaction mixture prior to treatment with allcali. The pure anhydrous material has been prepared by the high vacuum sublimation of the rnoriol~ydrate. he paper cl~rou~atogr apt iic , pectroscopic, an d Rc~orin~etric chara cteri stics o f aclrenoluti n have been invcsti gatecl. O n the basis of the ilifrarecl s pcctr~~~n it is suggestecl that ill the solicl state, atlrcnolutiri exists in the Iccto form, i.e. 2,s-dit~ydro- 5,6-dil~ydrox)~-N-~netl~yl-3-lictoinclole he infrared spectr um of adrenochron~e, n the solid statc, agrees with the zwitterionic for~n ulatio ri i~ggestccl or this compound. Adrenoluti11 (usually formulated as 3,5,6-trihydroxy-i\i-methylindole, ), the substance mainly responsible for the intense yellow-green fluo rescence t ha t develops in adrenal ine solutions th at have undergone oxidation in alltaline media, ~v as irst isolated in crystalline form an d correctly identified by Lu nd in 1949 ( I), from the alltaline real-rangement pro- duc ts o f adrenochrome (11), althou gh the correct stru ctu re had been assigned to the substance on theoretical gr ou ~lds year earlier (E hrlen (2)). Can. J. Chem. Vol. 36 (1858) The structure was subsequently confirnied by an ilnambiguous synthesis starting from 3,4-isoprop)rlideneclioxyaniline Balsiger et a l . (3)). h e preparatio n of adrenolutin from adrenaline oxidized with potassium ferricyanide i n aqueous bicarbonate buffer, follo~ved y rearrangement with aqueous sodium hydroxide and acidification ($), gave, in our hands, somewhat variable results, and good yields of pure procluct coulcl not be consistently obtained. It appeared that the product was con- taminated with inorganic resiclues from the oxidation mixture which probably catalyzed its decomposition. It has recently been shown that adrenochrome prepared by the oxida- tion o f adrena lin e with silver oxide u 7 as often con tamina ted \\ li t1 1 traces of silver, an d t ha t this contaminatio~i ould be minimized by passage of the reaction mixti~re hrough an ion-exchange resin (Domex-l (C1-)) prior to isolation of the proclucts (5). The use of t his procedure to renlove contaminants from ac11-e~~ochrome olutio~~s as now be e1 1 extend ed to the preparation o f ndrenolutin, and gave coilsislently good yields o f a drenoluti~~ ono- hydrate in a pure crystalli~~e ol-ni,Although t he wate r o f cryst alliza tion could be removed by drying in a vacuum desiccator, the anhydrous material was always obtained as an 21, 1068. Contribz~tio~~ rorrt the Psychiatric Rcsenrci~ Unit, U?~iversity Hospitr~l, nsknloon, Src.sk~~tckewn?c. h i s inuestigntion tons supported by gra?lts fro~ r~. lre Federal Dcprzrtnzerct o f I-lenlth n? ~d Velfnrc, nnd tlri! Rockefeller Fozrndalion. T l~is ork z8n.s carried out under the al~spices f the Saskntchewn?~ Cornaziltee on Scl~izoplzrcnie Research. 2Per t I-Can. J . Chem. 36, 863 (195s).
