Green approach for the synthesis of thiophenyl pyrazoles and isoxazoles by adopting 1,3-dipolar cycloaddition methodology and their antimicrobial activity

Abstract

A variety of N-((1,3-diphenyl-5-aryl-1H-pyrazol-4-yl)sulfonyl)thiophene-2-carboxamides (7) and N-((5-aryl-3-phenylisoxazol-4-yl)sulfonyl)thiophene-2-carboxamides (8) were prepared from (E)-N-(arylethenesulfonyl)thiophene-2-carboxamides (4) adopting 1,3-dipolar cycloaddition of nitrile imines and nitrile oxides generated from araldehyde phenylhydrazones and araldoximes in the presence of iodosobenzene and CTAB followed by oxidation with I2 in DMSO. The compounds 4f, 7e, 7f, 8e and 8f showed potential antibacterial activity against B. subtilis whereas 8e and 8f exhibited potential antifungal activity against A. niger.