Ultrasound-accelerated green and selective oxidation of sulfides to sulfoxides

Abstract

In the present paper we report a novel and green approach for the selective synthesis of sulfoxide from sulfide using ultrasound. Use of aqueous media and easily separable and recyclable reagents makes this process green. Hydrogen peroxide is used as an oxidizing agent. Ultrasound is used to enhance the rates of reaction and selectivity of the oxidation reaction toward the desired product (sulfoxide). The effect of various parameters such as the presence and absence of ultrasound, initial concentration of the reactants, reaction temperature, molar ratio of the reactant to the oxidizing agent, mode of addition of the oxidizing agent, presence and absence of β-cyclodextrin, and amount of β-cyclodextrin has been studied. The optimum operating conditions found for the oxidation reaction on the laboratory scale were equally effective at a scaled up version of the reaction.