Synthesis of some new annellated 1,2,4-Triazole systems from methyl 5-phenyl-2-hydrazinothiazolecarboxylate

The heterocyclization of hydrazides, prepared from methyl 5-phenyl-2-hydrozinothiazole-4-carboxylate and organic acids or their anhydrides, leads to the production of thiazolo2,3-c]triazoles which do not undergo rearrangement to the corresponding thiazolo3, 2-b]triazoles under the action of mineral acids. The 2-trifluoroacetylhydrazine derivative does not cyclize, even under severe conditions.A. E. Arbuzov Institute of Organic and Physical Chemistry of the Kazan Science Center, Russian Academy of Sciences, Kazan 420083. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 406–409, March, 1995. Original article submitted February 12, 1995.