Selectivity of hydrogenations. Part 3. N-methylquinolinium, N-methylisoquinolinium, and 4-(3-phenylpropyl)pyridinium salts

Abstract

N-Methyl fluorosulphonates of quinoline, 8-methyl- and 8-t-butyl-quinoline, isoquinoline, and 4-(3-phenylpropyl)pyridine were hydrogenated by catalysis on platinum, in methanol or in trifluoroacetic acid. Hydrogenation in methanol gave N-methylpiperidine derivatives; in trifluoroacetic acid hydrogenation of the benzene rings gave N-methylpyridinium derivatives. Reaction mixtures were analyzed by ¹³C n.m.r, spectroscopy and by isotachophoresis.