A new efficient route to 7-aryl-6-fluoro-8-nitroquinolones as potent antibacterial agents

A series of 7-aryl-6-fluoro-8-nitroquinolones ( 6a – e ) were synthesized through a novel, simple and clean synthetic procedure, through a Suzuki–Miyaura reaction. The target compounds were evaluated in vitro for their antimicrobial properties against bacterial and fungal strains. All of them showed antibacterial activity higher than the activity of ciprofloxacin, both towards Gram positive Bacillus subtilis and Staphylococcus aureus , and Gram negative Haemophilus influenzae strains. Compound 6d , containing the trisubstituted 7-aryl moiety, emerged as the most active quinolone derivative with MIC values ranging from 0.00007 μg/mL to 0.015 μg/mL.