Design, Synthesis, and In Vitro Antimicrobial Evaluation of Some New 6-(4-Phenoxyphenyl)-2-Arylpyridazin-3(2H)-One Derivatives

6-(4-Phenoxyphenyl)-2-arylpyridazin-3(2H)-one derivatives (2a-f) were synthesized and evaluated for in vitro antimicrobial activity. Synthesis of title compounds was carried out in two steps. The reaction of biphenyl ether with maleic anhydride resulted into 4-oxo-4-(4-phenoxyphenyl) but-2-enoic acid (1). Compound 1 on reaction with appropriate aryl hydrazines gave the title compounds (2a–f). The structures of all title compounds were characterized by IR, 1H-NMR, 13C-NMR, and mass spectral data.