Synthesis, spectral characterization and biological evaluation of 4H-1,4-benzothiazines, their sulfones and ribofuranosides

Abstract

Synthesis of heterocyclic compounds like benzothiazines has attracted attention in recent years due to their biological and industrial value. This article reflects up-to-date and comprehensive coverage of biochemical aspects of benzothiazines, their sulfones and ribofuranosides. The nitrogen and sulfur containing heterocycles were prepared by condensation followed by oxidative cyclization of 2-aminobenzenethiol with β-diketones/β-ketoesters in dimethylsulfoxide. These compounds were then used as base to prepare ribofuranosides by treating them with sugar (β-D-ribofuranose-1-acetate-2,3,5-tribenzoate). On refluxing with hydrogen peroxide in glacial acetic acid, these substituted dimethyl 4H-1,4-benzothiazines yielded 4H-1,4-benzothiazine-1,1-dioxides. Antioxidant and antimicrobial activity of these compounds were carried out and structure evaluation was done by spectral and elemental analysis.