Reaction of amide homologs, XIX. Thermal reactions of azomethines with formates and formamide.

Abstract

Thermal reactions of the representative azomethines of N-benzylidene type with the reagents, trimethylammonium formate given by 5HCO-2H·2N (CH3)3, ammonium formate and formamide, were examined in order to elucidate distinctions among them. The reduction and oxidation coureses as to the formate reaction and the formamide reaction were definitely distinguished from each other ; in the former reaction saturation of the azomethine double bond is induced by ixidation of formic acid to carbon dioxide and in the latter reaction reductive cleavage at the double bond, induced by self-oxidation of the azomethine, leads to the formation of the cleaved N-formylated primary amines. Elucidation on the mechanistic paths as to both of the essential reactions was investigated. Particularly, the pathways of the very complicated formamide reaction were declared to be of involving aldimine, hydroamide, N-arylmethylene-1-formamido-1-arylmethylamine and N, N'-arylmethylenebisformamide as major or minor intermediates.