Patents

The invention relates to an improved electrochemical process for the preparation of styrene epoxide from styrene through the  electrochemical oxidation of alkali metal bromide and an ionic liquid [(bmim)Br] as an electrolyte in an organic solvent and water  mixture at a temperature of 15 to 45°C is described. The electrolysis was carried out by constant current electrolysis condition in an  undivided batch cell at a current density of 10 to 100 mA/cm2 with platinum as anode and cathode. The invention particularly relates to the preparation of styrene epoxide in 86% yield by the electrolysis at a temperature of 15 to 45°C. The styrene conversion and styrene oxide selectivity is improved by the usage of ionic liquid as a catalyst. As the electrolyte used for the styrene oxidation is regenerated after epoxide formation, the electrolyte can be reused without any loss in the product yield. After completion of electrolysis the organic solvent was distilled out and the product was extracted with hydrophobic solvent to provide styrene oxide after usual work up.