Reaction of N-Aminopyridinium Derivatives. II. The Reactions of 1-(N-Acylalkylamino) pyridinium Salt Derivatives with Cyanide Ion. : A New Synthesis of Primary Amines.

1-(N-Monosubstituted amido) pyridinium compounds derived from novel quaternary salts of pyridine, N-aminopyridinium compounds, were quite reactive to nucleophilic agents at 2- and 4-positions of their pyridine rings, especially at 4-position. The 1-(N-monosubstituted amido) pyridinium salts were reacted with cyanide ion to give N-monosubstituted amides and cyanopyridines, (predominantly 4-cyanopyridine), both in good yields. The reaction may involve dihydro-type intermediates and one intermediate 1-(N-methylacetamino)-4-cyano-1, 4-dihydropyridine could be obtained stably. By utilizing this reaction, it would be possible to introduce a cyano group at 4-position of various pyridine derivatives and to obtain various primary amines.