Koch carbonylation of tertiary alcohols in the presence of acidic ionic liquids

Koch carbonylation of tertiary alcohol with CO was carried out in decane in the presence of acidic ionic liquid, which presents a novel application of acidic ionic liquid as well as a novel reaction system for Koch reaction that can offer good reusability and easy separation of product. Used as the probe reaction, carbonylation of tert-butyl alcohol with CO to pivalic acid was investigated under varying reaction conditions. A negative effect of air or water as additives on the yield of product was observed, while increasing the CO pressure from 4 to 8 MPa could remarkably benefit the reaction. Increasing reaction temperature from 120 to 160 °C also played a positive role, but a further elevation to 170 °C will lead to the decrease of product yield.