Recyclization reactions of heterocycles XVIII. Synthesis and recyclization of thiazolium and benzothiazolium salts

A number of thiazolium salts were obtained, and their reaction with hydrazine was studied. On reaction with hydrazine the aryl-substituted thiazolium salts are recyclized to dihydro-l, 2, 4-triazines, whereas on reaction with monoalkylhydrazines they are converted to 4H, 5H-1, 2-4-triazinium salts; thiazolium salts are converted to hydrazidohydrazones on reaction with phenylhydrazine. Recyclization to the dihydro-sym-tetrazine system was observed for 2-phenyl-substituted benzothiazolium tosylate.See 1] for communication XVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 635–640, May, 1976.