METHOD OF PREPARING 3-(METHYLTHIO)PROPANAL AND 2-HYDROXY-4-(METHYLTHIO) BUTANE NITRILE Russian patent published in 2001 - IPC

FIELD: organic chemistry. SUBSTANCE: described are improved method of preparing 3-(methylthio)propanal and method of preparing 2-hydroxy-4- (methylthio)butane nitrile therefrom. Method comprises reacting methyl mercaptan with acrolein in reaction zone in the presence of catalyst of reaction of olefin-mercaptan addition in combination with organic or inorganic acid. Catalyst comprises at least one organic base selected from group consisting of triisopropanol amine, tripropyl amine, imidazole, benzimidazole, 2-fluoropyridine, 4- dimethylaminopyridine, pycoline, pyrazine, N-methyldiphene-ethyl amine, N-ethyl-3,3'-diphenyldipropyl amine and trialkylamines containing from 5 to 12 carbon atoms in each alkyl substituent attached with nitrogen atom. Without preseparation from mixture comprising 3-(methylthio) propanal and used as intermediate product, the resulting 3-(methylthio) propanal and catalyst are treated with sodium cyanide to prepare 2- hydroxy-4-(methylthio)butane nitrile. Additional amount of base is added to the resulting intermediate product mixture. Method makes it possible to reduce amount of high-molecular impurities and to use commercially available bases. EFFECT: more efficient preparation method. 26 cl, 5 tbl