Novel synthesis of quinoline chalcone derivatives- Design, synthesis, characterization and antimicrobial activity

In the present study, an easy and conventional method has been adopted for the synthesis of novel 1-methyl-3-(3-oxo-3-phenylprop-1-enyl) quinoline-2-(1H)-ones (5a-i) by a condensation reaction of 1,2-dihydro-1-methyl-2-oxo quinoline-3-carbaldehyde (3) with substituted acetophenones (4a-i) and piperidine in the presence ethanol as a solvent. The structures of all the newly synthesized products were confirmed with their elemental analysis,H-1 NMR, C-13 NMR, FT-IR and mass spectral analysis. All the newly synthesized compounds (5a-i) were screened for in vitro antimicrobial activities (Minimum Inhibitory Concentration (MIC) by agar well diffusion method using gentamycin as positive and DMSO as a negative control. The tested, compounds 5f and 5i exhibited potent activity against S. aureus, B. subtilis, and S. Typhi, P. aeruginosa, where as compound 5a showed promising activity against S. aureus, B. subtilis, and S. Typhi, P. aeruginosa.