Synthesis and evaluation of novel fluorinated 2-styrylchromones as antibacterial agents

A range of fluorinated 2-styrylchromones (5a-g) of which six were new (5a-f) were prepared in three steps using the baker-venkataraman rearrangement along with two methoxylated derivatives (5h-i) and a methylenedioxy derivative (5j) and screened for their antibacterial activity using gram-positive bacteria (staphylococcus aureus,sciuri,and xylosus as well as bacillus subtilis) and gram-negative bacteria (escherichia coli,pseudomonas aeruginosa,and klebsiella pneumonia). the compounds were most effective against b. subtilis followed by s. aureus and a single strain of e. coli (atcc 25922). difluorination on the phenyl ring was shown to enhance antibacterial activity,and fluorine substitution at the 6 position was shown to be far superior to substitution at the 7 position. in comparison to tetracycline,the activity indices of the fluorinated styrylchromones ranged from 0.50 to 0.75 against b. subtilis. the crystal structure of 2′-fluoro-2-styrylchromone is also presented,and the molecule was shown to be planar. © 2013 mehbub momin et al.