A process of preparing a quinolone carboxylic acid or its derivatives havinga formula as shown below, comprises using a starting 7-flubro quinolone that.alreadyhas one or more desired substituents at one or more particular positions on thequinolone ring and preserving the orientation of such substituents throughoutthe synthesis. The present process comprises fewer steps than prior-art processes.The present process also can include a simple separation of a desired enantiomerof the quinolone carboxylic acid or its derivatives from the enantiomeric mixture.Pharmaceutical- compositions comprising fluoroquinolones prepared by thepresent process can be used effectively against a variety of microbial pathogens..
