Efficient and green sulfamic acid catalyzed synthesis of new 1,2-dihydroquinazoline derivatives with antibacterial potential

Abstract

A simple, efficient and eco-friendly method for the synthesis of 1,2-dihydroquinazolines has been developed using three-component reaction of readily available aromatic aldehydes, 2-aminobenzophenones, ammonium acetate with sulfamic acid as a green and recyclable catalyst. The significant features of this method include short reaction time, operational simplicity, high yields and high selectivity. Interestingly, the catalyst can be recovered and reused for up to four cycles without any loss in catalytic activity. By employing this method, a series of 23 compounds was synthesized and tested for antimicrobial activity against both Gram-positive and Gram-negative bacterial strains as well as a fungal strain. Among these, compounds 4l, 4v and 4w showed appreciable antibacterial activity selectively against Gram-positive bacteria, wherein compound 4w exhibited promising antibacterial activity with MIC value of 0.010 μMol L−1 against Staphylococcus aureus MTCC 96 and Micrococcus luteus MTCC 2470. In addition, 4w also showed promising bactericidal and biofilm formation inhibitory effects. Keywords: 1,2-Dihydroquinazolines, Sulfamic acid, Recyclability, Antimicrobial, Anti-biofilm