Research on arylhydrazones of substituted glyoxylic acids

3-Aryl-4-(arylhydrazonochloroformyl)-2-[(carbethoxy or carbarnoyl)cyanomethylene]-4-thiazolines were obtained by condensation of arylhydrazones of chloromethylglyoxylic chloride with arylamides of cyanomonothiomalonic acid ethyl ester or amide. The chlorine atom in these compounds is readily exchanged by a hydrazino group to give 3-aryl-4-(arylhydrazonohydrazinoformyl)-2-[(carbethoxy or carbamoyl)cyanomethylene]-4-thiazolines. 2-(Arylhydrazonocarbethoxyformyl)-4-(arylhydrazonochloroformyl)thiazoles were obtained by reaction of arylhydrazones of chloromethylglyoxylic chlorides with arylhydrazones of monothiomesoxalic acid ethyl ester amide. Arylhydrazones of ethyl 1H-tetrazolyl-5-glyoxylate were synthesized by condensation of arylhydrazones of ethyl cyanoglyoxylate with ammonium azide in dimethylformamide.