Sustainable Synthesis and Antimicrobial Assessment of 1,4-Dihydropyrimido[1,2-a]benzimidazole Derivatives

The increasing demand for environmentally friendly and efficient methods in chemical synthesis has driven the exploration of green chemistry approaches in medicinal chemistry. This study focuses on the sustainable synthesis of 1,4-dihydropyrimido[1,2-a]benzimidazole derivatives 4a–4o which have shown significant potential due to their diverse biological activities, particularly antimicrobial properties. The target compounds were synthesized using PEG-400 as a solvent, which proved to be the most effective. The antimicrobial activities of these derivatives against a range of pathogenic bacterial and fungal strains were evaluated using the broth dilution method. Compounds 4a–4o exhibited notable antimicrobial activity, and some of them showed competitive effectiveness compared to standard reference drugs.