Synthesis and anti-tubercular evaluation of some pyrrole derivatives

Abstract

Novel series of pyrrole derivatives were synthesized with an approach to reduce the growing anti-tubercular resistance and to develop more potent and less side effects having anti-tubercular, anti-inflammatory and anticancer activity. An efficient synthesis of different novel 2-amino-4,5-diphenyl-1-substituted-1H-pyrrole-3-carbonitrilesderivatives by the Paal- Knorr Condensation of benzoin with primary aromatic amines in refluxing ethanol resulted in the formation of ?-amino ketone intermediates, which were condensed without isolation, with malononitrile to yield the various 2-amino-4,5-diphenylpyrrole-3-carbonitriles ( 1a-d ). Pyrroles 1a-d reacted with different reagents such as acetic anhydride, sodium azide, hydroxyl amine hydrochloride to yield compound (1a1-1d1). The synthesized compounds were confirmed through spectral characterization using IR, 1H NMR and Mass. The Pyrrole derivatives examined for their in vitro anti-tubercular testing using Nitrate Reductase Assay. Activity of the synthesized compounds was carried out against H37RV bacteria. Result indicated that these compounds showed promising anti-tubercular activity in comparison to rifamycin (the standard anti-tubercular drug).