A ring enlargement from seven- to ten-membered-ring sulfonamide derivatives

Abstract

The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1a) with 4,S-dihydro-7,8-dimethoxy-l,2-benzothiazepin-3-one 1,1-dioxide (4) in dioxane at room temperature gave the correspondingly substituted 4H-1,2,5- benzothiadiazecin-6-one 1,1-dioxide 5a in 64% yield (Scheme 2). The structure of this novel ten-membered ring-enlargement product was established by X-ray crystallography (Fig.). Under more vigorous conditions (refluxing dichloroethane), 5a was formed together with the isomeric 6a, both in low yield. The 3-(dimethylamino)-2H- Show more