Synthesis and Biological Assessment of Novel Derivatives of 2-Oxo-tetrahydropyrimidine-5-carboxamides

Objective: Pyrimidine derivatives exhibit diverse biological activities, including antifungal, analgesic, antimicrobial, anti-inflammatory, and anticancer properties. This study focuses on the synthesis and evaluation of novel 5-carboxamide-2-oxo-tetrahydropyrimidine derivatives for their antibacterial and antifungal potential. Methods: Various 2-oxo-tetrahydropyrimidine-5-carboxamide derivatives (VIa–VIn) were synthesized via the reaction of N-arylacetoacetamides, urea, and substituted benzaldehydes in ethanol as a solvent, using a catalytic amount of ferric chloride with a trace of HCl. The progress of the reaction was monitored by TLC, and the products were purified by recrystallization. The structures of the synthesized compounds were characterized by IR, ¹H NMR spectroscopy, and mass spectrometry, with further confirmation by elemental analysis. Results and Discussion: The antibacterial and antifungal activities of all synthesized compounds were evaluated against standard microbial strains, including Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), and fungi (Aspergillus niger, Candida albicans). Compounds (VIc), (VIe), (VIg), (VII), (VIj), (VIk), and (VIn) exhibited significant antibacterial activity against both Gram-negative and Gram-positive bacteria. Similarly, compounds (VIc), (VId), (VIe), (VII), (VIj), (VIk), and (VIn) demonstrated potent antifungal activity against A. niger and C. albicans. Several of these compounds showed greater potency than standard antibiotics and antifungal drugs. Conclusions: In this study, novel pyrimidine derivatives were synthesized and evaluated for their antibacterial and antifungal properties. The results suggest that these compounds hold promise as potential leads for the development of new antimicrobial agents. Further research is necessary to elucidate their mechanism of action and assess their in vivo efficacy.