An efficient synthesis and antimicrobial screening of new hybrid molecules containing coumarin and indenopyridine moiety

A novel series of hitherto unknown 3-(4-aryl-5H-indeno[1,2-b]pyridin-2-yl)coumarin derivatives 3a-r have been synthesized by the reaction of 3-coumarinyl methyl pyridinium salts 1a-c with appropriate 2-arylidene-1-indanones 2a-f under Krohnke's reaction condition so as to investigate their in vitro antimicrobial activity. Structures of the target compounds 3a-r were characterized by their spectral and elemental analyses. Among the series, compound 3l displayed an encouraging antibacterial activity profile as compared to the reference drug ampicillin against tested bacterial strains.