Synthesis and antimicrobial activity of N¹-(3-chloro-4-fluorophenyl)-N⁴-substituted semicarbazone derivatives

A series of 16 N¹-(3-chloro-4-fluorophenyl)-N⁴-substituted semicarbazone derivatives were synthesized and subjected to computational pharmacokinetic studies to predict molecular properties. All the title compounds (4a–p) followed the Lipinski “Rule of Five”. The synthesized compounds were characterized by elemental analyses and spectral data and the compounds (4a–p) were evaluated for antimicrobial activities. Among them the compound 2-(4-hydroxybenzylidene)-N-(3-chloro-4-fluorolphenyl)hydrazinecarboxamide (4f) was found to be the most active compound that showed good antibacterial activity while the compound 2-(4-methoxybenzylidene)-N-(3-chloro-4-fluorolphenyl)hydrazinecarboxamide (4g) was moderately active against fungal strains. We have noticed that the compounds, (4f, 4k and 4d) bearing OH and NO₂ groups on the phenyl ring at position 4 exhibited good antibacterial activity while compound (4g) bearing OCH₃ on the phenyl ring at position 4 exhibited moderate antifungal activity.