In the presence of bis(acetylacetonato)oxovanadium(IV), dibenzothiophene was oxidized by hydrogen peroxide to form sulfoxide and sulfone products. The percentage of dibenzothiophene remaining after the oxidation and the ratio of these oxidation products, as determined by H-1 NMR spectroscopy, was largely dependent on the solvent used. Reactions in acetonitrile consumed more than 99% of the dibenzothiophene in the reaction and yielded the sulfone as the major product. The efficacy of biphasic oxidations performed in heptane and acetonitrile were dependent on the ratio of acetonitrile to heptane with a higher proportion of acetonitrile resulting in greater consumption of dibenzothiophene. After multiple oxidations, all of the dibenzothiophene was removed from the heptane solution. (C) 2011 Elsevier B.V. All rights reserved.