An Environmentally Benign Lemon Juice Mediated Synthesis of Novel Furan Conjugated Pyrazole Derivatives and Their Biological Evaluation

Abstract

A series of furan conjugated pyrazole derivatives were synthesized by an accessible and eco-friendly approach. The method involves the reaction of chalcones and phenylhydrazine hydrochlorides in the presence tetrabutylammonium bromide as phase transfer catalyst (PTC) in freshly extracted lemon juice medium. The reaction afforded a series of triaryl and diaryl substituted pyrazoles in moderate to good yields. Structures of synthesized new pyrazoles were Confirmed by spectral studies and elemental analysis. Preliminary studies showed that, among the synthesized series, compounds 5i and 5j with chloro substitution in one of the aromatic rings and compound 7c exhibited excellent activity against S. aureus, P. aeruginosa, and E. coli species. Compounds 5i and 5j also showed excellent antifungal activity against A. niger, A. flavus, and C. albicans species. Compounds, 5c, 5d, 5i, 5j and 7c exhibited excellent DPPH radical scavenging activity.