Novel convenient approach to 1,4,2-benzodithiazine-1,1-dioxides and 1,2,3-benzoxathiazine-2,2-dioxides

A new effective method for the construction of 1,4,2-benzodithiazine and 1,2,3-benzoxathiazine scaffolds, based on the use of easily accessible N-chlorosulfonyltrichloroacetimidoyl chloride, has been developed. Reactions of thiophenols involved an initial nucleophilic substitution at the imine carbon atom with a thiol sulfur atom, followed by intramolecular sulfonylation of the benzene ring. Phenols exhibit opposite regioselectivity and react by electrophilic imidoylation of the ortho-carbon atom of the benzene ring (C-C bond formation) and sulfonation of the phenol oxygen atom. Synthesized 1,4,2-benzodithiazine-1,1-dioxides exhibit growth-stimulating activity on monocotyledonous winter wheat "Bezosta" and dicotyledonous plants Barbarea arcuate.