Oxidation of dibenzothiophene by hydrogen peroxide in the presence of bis(acetylacetonato)oxovanadium(IV)

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 1H 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.

► VO(acac)2 as catalyst for the oxidation of dibenzothiophene by hydrogen peroxide.
► Sulfone/sulfoxide product ratio influenced by choice of solvent and conditions.
► Greater than 99% of the dibenzothiophene is oxidized in acetonitrile.
► Achieved at 22 °C in 2 h or 40 °C in 30 min.
► Biphasic oxidation and extraction removes dibenzothiophene from heptane.