When treated with an excess of MeONa in DMF, 5-benzylsulfonyl-3-chloro-4-methoxy-carbonylaminoisothiazole undergoes cyclization into 3-methoxy-5-oxo-6-phenyl-5,6-dihydro-4H-isothiazolo[5,4-b]-1,4-thiazine 7,7-dioxide, the first representative of a new heterocyclic ;system. The starting 5-benzylsulfonyl-3-chloro-4-methoxycarbonylaminoisothiazole was prepared by the reaction of 5-benzylsulfonyl-4-carbamoyl-3-chloroisothiazole with PhI(OAc)(2) in methanol.
When treated with an excess of MeONa in DMF, 5-benzylsulfonyl-3-chloro-4-methoxy-carbonylaminoisothiazole undergoes cyclization into 3-methoxy-5-oxo-6-phenyl-5,6-dihydro-4H-isothiazolo[5,4-b]-1,4-thiazine 7,7-dioxide, the first representative of a new heterocyclic ;system. The starting 5-benzylsulfonyl-3-chloro-4-methoxycarbonylaminoisothiazole was prepared by the reaction of 5-benzylsulfonyl-4-carbamoyl-3-chloroisothiazole with PhI(OAc)(2) in methanol.
When treated with an excess of MeONa in DMF, 5-benzylsulfonyl-3-chloro-4-methoxy-carbonylaminoisothiazole undergoes cyclization into 3-methoxy-5-oxo-6-phenyl-5,6-dihydro-4H-isothiazolo[5,4-b]-1,4-thiazine 7,7-dioxide, the first representative of a new heterocyclic ;system. The starting 5-benzylsulfonyl-3-chloro-4-methoxycarbonylaminoisothiazole was prepared by the reaction of 5-benzylsulfonyl-4-carbamoyl-3-chloroisothiazole with PhI(OAc)(2) in methanol.