A Novel and Efficient Regiospecific Preparation of Arenesulfonamide Derivatives of 3,5-Diamino-1,2,4-triazole

Abstract

A new simple and efficient procedure was designed for the regiospecific preparation of arenesulfonamide derivatives of 3,5-diamino-1,2,4-triazole 1 which are precursors of N-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)arenesulfonamides 2, an important family of herbicidal and antibacterial agents, The key feature of this procedure is the preparation of a wide range of compounds 1 on a large scale, in pure form and high yield without the need for any workup or the use of the highly hazardous hydrazine. This was made possible by a novel tandem reaction promoted by sulfuryl chloride to effect the formation of the triazole ring.