A process of preparing a quinolone carboxylic acid or its derivatives havinga Formula as shown below, comprises using a starting quinolone that already hasone or more desired substituents at one or more particular positions on the quinolonering and preserving the orientation of such substituents throughout the synthesis.The present process comprises fewer steps than prior -art processes. The presentprocess also can include a simple separation of a desired enantiomer of the quinolonecarboxylic acid or its derivatives from the enantiomeric mixture. Pharmaceuticalcompositions comprising fluoroquinolones prepared by the present processcan be used effectively against a variety of microbial pathogens.
