Oxidation of Sulfides with Tetraalkylammonium Dichlorobromate(1-)

The oxidation of aliphatic sulfides with a nearly equimolar amount of tetrabutylammonium (or benzyltrimethylammonium) dichlorobromate(1-) in aqueous sodium hydroxide and dichloromethane, in aqueous acetic acid, or in aqueous pyridine gave the corresponding sulfoxides in good yields. Meanwhile, the reaction of aromatic sulfides such as diphenyl sulfide and thianthren depends on the oxidation methods and reaction conditions. The reaction of benzyl phenyl and dibenzyl sulfide in aqueous acetic acid gave the corresponding sulf oxides with a small amount of cleavage products of the C-S bond. The reaction of benzyl phenyl sulfide in aqueous sodium hydroxide and dichloromethane gave the brominated sulfones.