New racemic N•(••azifidin•).6.flu•r••7.(4•methy•piperazin•••y•).4(•H).quin•••ne•3.•arboxy•ic acids (9a-i) were ~ynthesized and their antibacterial activities were tested against Gram-positive and Gramnegative micro-organisms. According to the MIC, all compounds studied are less active than Ciprofloxacin; two of them (ga,b) have similar activity as Nalidixic acid (1).