Synthesis and Antimicrobial Activity of Some New Quinazolin-4(3H)-one Derivatives

A new series of 6-iodo-2-phenylquinazolin-4(3H)-one derivatives was prepared and screened for antimicrobial activity. The thioureide derivatives 4–6, the carbohydrazide derivatives 19–21 and 24 displayed excellent broad-spectrum antimicrobial activity. Some compounds showed moderate activity against Candida albicans and Pseudomonas aeruginosa. None of the tested compounds was as active as the reference standard drugs ampicillin and clotrimazole. The detailed synthesis, antimicrobial activity, and the minimum inhibitory concentrations (MIC) are reported.