Synthesis and in vitro Antibacterial Evaluation of N-[5-(5-Nitro-2-thienyl)-1,3,4-thiadiazole-2-yl] Piperazinyl Quinolones.

Abstract

Abstract A series of N -[5-(5-nitro-2-thienyl)-1,3,4-thiadiazole-2-yl]piperazinyl quinolones ( 7a–c ) were synthesized and evaluated for in vitro antibacterial activity against some Gram-positive and Gram-negative bacteria. The antibacterial data revealed that compounds 7a – c had strong and better activity against tested Gram-positive organisms than the reference quinolones such as ciprofloxacin, norfloxacin and enoxacin. However, all three compounds were nearly inactive against Gram-negative bacteria. Compound 7a (ciprofloxacin analogue) was the most active compound against Gram-positive bacteria (MIC=0.008–0.015 μg mL −1 ).