Abstract
Catalytic hydrogenation of some azomethines, such as N-benzylideneaniline, N-benzylidenebenzylamine, and N- (4-methoxybenzylidene) phenethylamine in the presence of amide was examined under high pressure of hydrogen. The reaction resulted in conversion, ArCH=NR+2R'CONH2+H2→ArCHNHCOR'+RNHCOR'+NH3, particularly in excellent yields with formamide. With regard to this reaction path, it was recognized that the initiating essential reaction between azomethine and formamide would be the reaction, ArCH=NR+HCONH2→ArCH=NH+RNHCHO (NH3 acts as a catalyst), which was demonstrated by using N-benzylidene-4-sulfonamidobenzylamine as azomethine. Based on this reaction, the whole pathway for the above hydrogenation reaction was proposed. Mechanism for hydrogenation reaction of nitriles, oximes, and ammoniaaldehyde mixtures in the presence of formamide was also suggested.
