Tandem Carboxylation-Hydration Reaction System from Methanol, CO2 and Benzonitrile to Dimethyl Carbonate and Benzamide Catalyzed by CeO2

CeO2 is an effective catalyst for a new tandem reaction system; The synthesis of dimethyl carbonate (DMC) from methanol+CO2 and benzonitrile hydration to benzamide. In combination with benzonitrile hydration, the yield of DMC was drastically promoted even at CO2 pressures as low as 0.1 MPa. The yields of methanol-and CO2-based DMC were as high as 47% and 70%, respectively. Calcination of the catalyst at 873 K after the reaction, enables the catalyst to be reused without any structural change, although benzamide, produced by the benzonitrile hydration, poisons of the catalyst. This reaction system can be applied to the synthesis of other dialkylcarbonates from their corresponding alcohols and CO2.