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

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, 1 H 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 µg/mL) and streptomycin (MIC 6.25 µg/mL).