Synthesis of 6‐halogenated 4H‐1,4‐benzothiazines

Abstract

The synthesis of 6‐halogenated 4H‐1,4‐benzothiazines is reported by the condensation and oxidative cyclization of 4‐substituted 2‐aminobenzenethiols (I, R = Cl, Br) with β‐diketones in presence of DMSO. The ir, nmr and mass spectral studies are included. 4‐Substituted 2‐aminobenzenethiols were also prepared by an improved and direct method.