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 CH 3 COOH in ethanol. The structures of these compounds were elucidated by, IR, 1 H NMR, 13 C 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 (5 R )-5-(furan-2-yl)-1-phenyl-3-[2-(benzyloxy)phenyl]-4, 5-dihydro-1 H -pyrazole ( 2b ) and (5 R )-5-(furan-2-yl)-1-phenyl-3-[2-(naphthalen-2-ylmethoxy prop-2-en-1-yloxy)phenyl]-4,5-dihydro-1 H -pyrazole ( 2d ) showing most promising antibacterial activities as compared to Gentamicin and Tetracycline are given.