title: Oxidation of quinolones with peracids (an in situ EPR study).
abstract: 4-Oxoquinoline derivatives (quinolones) represent heterocyclic compounds with a variety of biological activities, along with interesting chemical reactivity. The quinolone derivatives possessing secondary amino hydrogen at the nitrogen of the enaminone system are oxidized with 3-chloroperbenzoic acid to nitroxide radicals in the primary step while maintaining their 4-pyridone ring. Otherwise, N-methyl substituted quinolones also form nitroxide radicals coupled with the opening of the 4-pyridone ring in a gradual oxidation of the methyl group via the nitrone-nitroxide spin-adduct cycle. This was confirmed in an analogous oxidation using N,N-dimethylaniline as a model compound. N-Ethyl quinolones in contrast to its N-methyl analog form only one nitroxide radical without a further degradation.
authors.affiliation: Faculty of Chemical and Food Technology, Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic.
authors.forename: Andrej
authors.initials: A
authors.lastname: Staško
authors.forename: Viktor
authors.initials: V
authors.lastname: Milata
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Barbieriková
authors.forename: Vlasta
authors.initials: V
authors.lastname: Brezová
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D002723:Chlorobenzoates / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D015363:Quinolones / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D002723:Chlorobenzoates; D015363:Quinolones; C036427:3-chlorobenzoic acid; C005141:dimethylaniline N-oxide; D010100:Oxygen
keywords: EPR spectroscopy; N,N-dimethylaniline; nitroxide; oxidation; peracids; quinolones