N-amination and subsequent oxidation of some fused imidazoles and triazoles

Abstract

N-Amination of imidazo[1,2-a]pyridines, pyrido[1,2-a]benzimidazole, s-triazolo[1,5-a]pyridines, and s-triazolo-[4,3-a]pyridines is described. 1-Amino-s-triazolo[1,5-a]pyridinium salts were also obtained by cyclizing 2-(2-acylhydrazino)-1-aminopyridinium salts. Oxidation of 10-aminopyrido[1,2-a]benzimidazolium bromide and 1-amino-s-triazolo[1,5-a]pyridinium salts with bromine gave 10,10′-azopyrido[1,2-a]benzimidazolium and 1,1′-azo-s-triazolo[1,5-a]pyridinium salts, respectively. Similar oxidation of 3-amino-2-methyl-1-phenylbenzimidazolium bromide and 1-amino-s-triazolo[4,3-a]pyridinium salts resulted in deamination.