Synthesis, Characterization and In Vitro Antimicrobial Evaluation of Some New Benzofuranyl Substituted Pyrido [3, 2-C] Coumarins

In the present study, a series of benzofuranyl substituted pyrido [3, 2-c] coumarins (4a-l) were synthesized by the reaction of various 4-hydroxycoumarins (1a-c) and appropriate 1- (benzofuran-2-yl) -3-aryl prop-2-en-1-ones (chalcones) (3a-d) under Krohnke?s reaction condition. The structure of all the synthesized compounds elucidated by elemental analysis, IR, 1H-NMR, 13C-APT and some representative mass spectral data. The compounds were subjected to in vitro antimicrobial screening against selected bacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Salmonella typhi) and fungal (Candida albicans and Aspergillus niger) pathogens. Compounds 4b, 4e, 4f, 4g, 4i, 4j and 4k displayed excellent antimicrobial activity and served as the most promising leads of the series.