Synthesis and In-Vitro Antimycobacterial Evaluation of 4-Arylidene-2-Phenyl-6-(Aryl)-4,5-Dihydropyridazin-3(2H)-One Derivatives

A series of 4-arylidene-2-phenyl-6-(aryl)-4,5-dihydropyridazin-3(2H)-one derivatives (3a-3g and 3a'-3g') have been synthesized and evaluated as antimycobacterial agents by microplate alamar blue assay (MABA) method. Title compounds 3a-3g and 3a'-3g' were synthesized by reaction of 6-aryl-2-phenyl-4,5-dihydropyridazin-3(2H)-one (2a, 2b) with various aromatic aldehydes. Compounds 2a and 2b were synthesized from 4-aryl-4-oxobutanoic acids (1a,1b) by reaction ofphenyl hydrazine with appropriate aromatic compounds and succinic anhydride. The structures of synthesized compounds have been established by IR, H-1 NMR, and mass spectroscopy and elemental analysis. All synthesized compounds (3a-3g and 3a'-3g') exhibited significant antimycobacterial activity. Compound 3g showed maximum activity and compounds 3b, 3b', 3e, 3e', 3g'showed moderate activity as compared to the reference drugsisoniazid (MIC 3.125 mu g/mL) and streptomycin (MIC 6.25 mu g/mL).