Photochemistry of oxazolidinones antibacterial drugs

The photochemistry of six N3-(3-fluoro-4-dialkylaminophenyl)-oxazolidinones known for their antimicrobial activity has been examined. All of these compounds are defluorinated in water (dec ≈ 0.25) and in methanol (dec ≈ 0.03), reasonably via the triplet. The chemical processes observed are reductive defluorination and solvolysis, depending on the structural variation introduced (thus, tethering the dialkylamino group to the aromatic ring and introducing a highly polar group in the oxazolidinone moiety have an effect). A likely mechanism involves the fragmentation of the C-F bond yielding the corresponding triplet phenyl cation. This intermediate either is reduced or, under appropriate conditions, intersystem crosses to the singlet state that adds the solvent.