Synthesis, characterization and in vitro antimicrobial assessment of some novel 4H-1, 4-benzothiazines and their sulfone derivatives

Abstract

Abstract In recent years, synthesis and biological evaluation of novel 4H-1,4-benzothiazines and their sulfone derivatives have gained momentum due to their medicinal and industrial importance. Our studies focused on the design and synthesis of new antimicrobial agents, and for this purpose a series of novel 4H-1,4-benzothiazines and their sulfone derivatives were synthesized and their in vitro antimicrobial assessment was carried out against a representative panel of Gram-positive and Gram-negative bacteria strains and selected fungi species. The reported 4H-1,4-benzothiazines were prepared by condensation followed by oxidative cyclization of substituted 2-aminobenzenethiols with compounds containing active methylene groups. It is believed that the reaction proceeds via intermediary of the enaminoketone system. The sulfone derivatives were synthesized by oxidation of 4H-1,4-benzothiazines using 30% hydrogen peroxide in glacial acetic acid. Structure determination was done by spectral and elemental investigations.