Synthesis and antimicrobial activity of novel substituted 2-(9-ethyl-9H-carbazol-3-yl)-4H-chromen-4-one derivatives

A series of novel carbazole tethered chromone derivatives were synthesized from 3-(9-ethyl-9H-carbazol-3-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one. The structures of newly synthesized compounds were confirmed by their IR, 1H NMR, 13C NMR and mass spectral data. The synthesized compounds were evaluated for their in vitro antimicrobial activity. Notably, compound 5a with a broad antimicrobial spectrum was the only compound exhibiting activities against all test bacterial and fungal strains as compared to standard drug ampicillin. Most of the newly synthesized compounds (4, 5, and 6) have moderate to good antimicrobial activities.