Synthesis, spectral characterization, and antituberculosis activity of thiazino[3,2-A]benzimidazole derivatives

A series of novel thiazino[3,2-a]benzimidazole derivatives synthesized by cyclization of (R)-2-(chloromethyl)oxirane with benzimidazole-2-thiol followed by reacted with benzyl bromides in high yield under milder conditions. The molecular structures of all compounds were confirmed by ¹H and ¹³C NMR spectroscopy and Mass spectrometry. The absolute configuration of the compounds was confirmed by X-ray diffraction analysis. All the synthesized compounds were evaluated in vitro for their antituberculosis activity.