An ionic liquid-mediated expeditious route to the syntheses of diaryl sulfoxides

A fast and efficient protocol is proposed for the synthesis of diaryl sulfoxides in the ionic liquid 1-butyl-3-methylimidazolium chloroaluminate, [bmim]Cl·AlCl3, N=0.67, by employing arenes and thionyl chloride. The ionic liquid plays a dual role of Lewis acid catalyst and solvent, under ambient conditions, offering good yields of the product. The influence of the Lewis acidity of the ionic liquid on the extent of conversion is studied.