Rapid Conversion of Sorbitol to Isosorbide in Hydrophobic Ionic Liquids under Microwave Irradiation

Sorbitol was effectively converted to isosorbide by treatment with [TMPA][NTf2] in the presence of catalytic amounts of TsOH under microwave heating at 180 °C. The reaction completed within 10 min and isosorbide was isolated to about 60 %. Ionic liquids were readily recovered by an extraction treatment and reused several times. As easy as cooking instant food! Only 10 min of microwave irradiation efficiently converts sorbitol in hydrophobic ionic liquids to isosorbide. A catalytic amount of acid accelerates the reaction. Separation of ionic liquids and isosorbide is easily achieved by an extraction method and recovered ionic liquids can be used in several iterations of the reaction.