SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL EVALUATION OF NOVEL THIENO [2,3-D] PYRIMIDINE-BASED BENZAMIDE DERIVATIVES

A new series of thieno[2,3-d]pyrimidine derivatives bearing substituted benzamide moieties (4a-j) was synthesized and evaluated for antimicrobial activity. The synthesis involved formation of a dithiocarbamate intermediate, S-methylation, hydrazine-mediated cyclization to the pyrimidinone core, thiol methylation, and final acylation using substituted benzoyl chlorides. The structures of all synthesized compounds were confirmed by IR, ¹H NMR and ¹³C NMR. All compounds were evaluated for antimicrobial screening against selected bacterial and fungal strains revealed that compounds containing electron-withdrawing groups exhibited enhanced activity. The study highlights thieno [2,3-d]pyrimidine benzamides as promising scaffolds for antimicrobial drug development.