Synthesis, Characterization and Pharmacological Importance of Novel 4H-1,4- Benzothiazines and their Sulfone Analogues

4H-1,4-Benzothiazines and its derivatives are potential pharmacologically and industrially useful agents. They were prepared by condensation followed by oxidative cyclization of 2-amino-4,6-dimethylbenzenethiol with varied βdiketones/β-ketoesters in dimethyl sulfoxide. On refluxing with H2O2 in glacial acetic acid, the substituted 4H-1,4Benzothiazines yielded 4H-1,4-Benzothiazine-1,1-dioxides (sulfones). These compounds were evaluated for antioxidant activity by DPPH and ABTS assay and the antimicrobial properties were investigated against various strains of bacteria (Coagulase negative Staphylococci, Coagulase positive Staphylococci, Enterobacter) and fungi (Candida albicans) using Paper disc method. The structures of the compounds have been confirmed by spectral and elemental analysis.