Synthesis and Study of Some New Quinolone Derivatives Containing a 3-acetyl Coumarin for Their Antibacterial and Antifungal Activities

A series of N-[2-(8-metoxy-2H-chromen-2-one)ethyl] piperazinyl quinolones containing a carbonyl related functional groups (oxo or oxyimino) on the ethyl spacer of coumarin and piperazin rings was synthesized and studied for their antibacterial and antifungal activities . The synthesis of compounds (6a-6l) was achieved through the versatile and efficient synthetic route that involved reaction of quinolones with appropriately α-bromo ketone or α-bromo oxime derivatives (2, 2a-c). The structures of the new compounds were confirmed by IR, Mass, 1H-NMR and 13C-NMR spectra. More good activities against gram-positive and gram-negative are shown in all compounds. Antibacterial screening of compounds 6a–l against gram-positive and gram-negative bacteria reveals that compounds 6g, 6h and 6i exhibit the most potent in-vitro antibacterial activity. The antifungal data reveals that all compounds have shown weak antifungal activity as compared to Nistatin.