Synthesis and antibacterial evaluation of 3-acetyl-2H-selenopyrano[2,3-b]quinolin-2-ones

In the present study, we have worked out a convenient route for the synthesis of new series of novel 3-acetyl-2H-selenopyrano[2,3-b]quinolin-2-ones (4a-f) by the cyclization of 3-formyl-2-selenoquinolines (3a-f) using ethyl acetoacetate in the presence of catalytic amount of piperidine in acetonitrile as a solvent. The structures of all the synthesized products were confirmed with their elemental analysis, IR, 1H NMR, 13C NMR and mass spectral analysis. All the newly synthesized compounds (4a-f) were screened for in vitro antibacterial activities of three (Staphylococcus aureus, Micrococcus roseus) and (Escherichia coli) by disk diffusion method using ampicillin as positive and Dimethylformamide (DMF) as negative control. The tested, compounds 4d and 4e were highly active against S. aureus and M. roseus (gram positive) and moderately active against E. coli (gram negative), compound 4c was slightly active against M. roseus and E. coli. Compound 4e was slightly active against S. aureus and M. roseus and compounds 4a and 4b were slightly active against M. roseus.