Synthesis and antibacterial evaluation of novel analogs of fluoroquinolones annulated with 6-substituted-2-aminobenzothiazoles

Keeping in view the immense biological importance of fluoroquinolones and aminobenzothiazoles as antimicrobials and in search for better antibacterial agents, design and synthesis of new fluoroquinolone derivatives having substituted piperazine rings at the C-7 position are described in the present communication. The synthesized compounds were characterized by suitable spectroscopic methods. Most of the new compounds (4a–l) demonstrated high in vitro antibacterial activity with some compounds exhibiting more potent activities against Gram-positive organisms than those of ciprofloxacin, norfloxacin and gatifloxacin. The results of the present study reveal that the compounds have significant antibacterial potential and are suitable candidates for further exploration.