A 6-fluoroquinolone (norfloxacin) and the naphthyridine analogue enoxacin give the corresponding 6-hydroxy derivatives by irradiation in water at pH 7.2 and, with lower efficiency, at pH 4.5 and 10. At pH 1 no defluorination takes place and the piperazinyl side chain is degraded. The 6,8-difluoro derivative lomefloxacin is defluorinated selectively from position 8 over the entire pH range considered (pH 1 to 10). The intermediate cation in position 8 does not add water and rather undergoes insertion into the β-CH bond of the neighboring N-ethyl group. The cation adds chloride, however. The structure–photoreactivity relationship for fluoroquinolones and the relation with the known phototoxicity of these compounds are commented upon.
Photochemistry of some fluoroquinolones. Effect of pH and chloride ion
FASANI, ELISA;
2000-01-01
Abstract
A 6-fluoroquinolone (norfloxacin) and the naphthyridine analogue enoxacin give the corresponding 6-hydroxy derivatives by irradiation in water at pH 7.2 and, with lower efficiency, at pH 4.5 and 10. At pH 1 no defluorination takes place and the piperazinyl side chain is degraded. The 6,8-difluoro derivative lomefloxacin is defluorinated selectively from position 8 over the entire pH range considered (pH 1 to 10). The intermediate cation in position 8 does not add water and rather undergoes insertion into the β-CH bond of the neighboring N-ethyl group. The cation adds chloride, however. The structure–photoreactivity relationship for fluoroquinolones and the relation with the known phototoxicity of these compounds are commented upon.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
