Oxidation of organic compounds with quinquevalent vanadium. Part 15. Oxidation of 2,6-dimethylphenol

Abstract

The oxidation of 2,6-dimethylphenol by acid aqueous vanadium(V) solution has been studied in the presence both of added acetonitrile and of acetic acid. In the case of the former solvent the reaction can be followed by a conventional u.v. spectrophotometer, but the reaction in acetic acid is much faster and a stopped-flow spectrophotometer, constructed of oxidant- and acid-inert materials, was also used. Under both conditions the main products were monomeric and dimeric quinones, and the reactions are second order in vanadium(V). Under both conditions there is evidence for the inital formation of a vanadium(V)–phenol complex which is then further attacked by a further vanadium(V) species. The reactions are acid catalysed.