Synthesis, studies and in-vitro antibacterial activity of N-substituted 5-(furan-2-yl)-phenyl pyrazolines

Abstract

Novel compounds with antibacterial properties: pyrazoline derivatives were synthesized by the cyclization of various -1-[2-(alkoxy)phenyl]-3-(furan-2-yl) prop-2-en-1-one 1a–1d with N-substituted phenyl hydrazine in the presence of CH3COOH in ethanol. The structures of these compounds were elucidated by, IR, 1H NMR, 13C NMR, ESI-MS spectral data and their purities were confirmed by elemental analyses. The in vitro antibacterial activity of these compounds was evaluated against two Gram-positive and two Gram-negative bacteria Aeromonas hydrophila, Yersinia enterocolitica, Listeria monocytogenes, and Staphylococcus aureus by microdilution method and then the minimum inhibitory concentration (MIC) of compounds were determined. The results showed that compounds (5R)-5-(furan-2-yl)-1-phenyl-3-[2-(benzyloxy)phenyl]-4, 5-dihydro-1H-pyrazole (2b) and (5R)-5-(furan-2-yl)-1-phenyl-3-[2-(naphthalen-2-ylmethoxy prop-2-en-1-yloxy)phenyl]-4,5-dihydro-1H-pyrazole (2d) showing most promising antibacterial activities as compared to Gentamicin and Tetracycline are given.