Synthesis of 1,1′-dimethyl-4,4′-azo-1,2,4-triazolium and 3,3′-dimethyl-1,1′-azobenzotriazolium salts

Abstract

The synthesis of 1,1′-dimethyl-4,4′-azo-1,2,4-triazolium salts, by oxidation of 4-amino-1,2,4-triazoles followed by quaternisation of the derived tetrazenes with methyl fluorosulphonate, is described. The azotriazolium salts were also obtained by oxidising the methobromides of 4-amino-1,2,4-triazoles with saturated aqueous bromine. No 1,1′-azobenzotriazole was isolated when 1-aminobenzotriazole was oxidised with acidified potassium bromate but the required title salts were obtained by oxidation of 1-aminobenzotriazole methobromide with saturated aqueous bromine.