ISOLATION AND STRUCTURE ELUCIDATION OF AN INTERMEDIATE IN THE PHOTODEGRADATION OF CIPROFLOXACIN

Ciprofloxacin decomposes photochemically in aqueous solutions at acidi c pH forming two major degradation products. One of the products, isol ated from irradiated solutions by flash chromatography, was cyclopropy l-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid. The compound was an intermediate in the photochemical process, which degraded afte r longer exposure with a high-pressure mercury lamp to an aromatic ami no-compound, cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carbox ylic acid. The structure of the intermediate was elucidated on the bas is of information from ultraviolet, mass and nuclear magnetic resonanc e spectra. (C) 1997 Elsevier Science B.V.