New synthesis of some 1,2,5‐benzothiadiazcpinc 1,1‐dioxide derivatives. I

Abstract

Abstract 2‐Nitrobenzenesulfonyl chloride reacts with ω‐aminoacetophenone and 4‐amino‐3,5‐dimethyl‐isoxazole to give 3 and 7, respectively. Reduction of 3 with zinc powder and acetic acid afforded the 2,5‐dihydro‐ and 2,3,4,5‐tetrahydro‐1,2,5‐benzothiadiazepine I,1‐dioxide derivatives (4 and 5). Catalytic hydrogenolysis of 7 and successive cyclization of the intermediate 8 gave the 3‐ace‐thyl‐2,5‐dihydro‐4‐methyl‐1,2,5‐benzothiadiazepine 1,1‐dioxide (9). The structures were assigned on the basis of correct elemental data and spectroscopic evidences.