Improved synthesis of DQ-113, a new quinolone antibacterial agent, utilizing the Reformatsky reaction

A new improved synthetic route for the C-7 substituent in DQ-113, a new quinolone antibacterial agent for infections caused by Gram-positive pathogens, has been developed which does not use low temperatures and avoids the use of expensive fluorinating agents. The key step is a Reformatsky reaction between ethyl bromofluoroacetate and ethyl 1-acetylcyclopropanecarboxylate.