Transesterification of Diethyl Oxalate with Phenol over Sol–Gel MoO3/TiO2 Catalysts

Abstract The transesterification of diethyl oxalate (DEO) with phenol to form diphenyl oxalate (DPO) has been carried out in the liquid phase over very efficient MoO 3 /TiO 2 solid‐acid sol–gel catalysts. A selectivity of 100 % with a remarkable maximum yield of 88 % were obtained, which opens the route to downstream phosgene‐free processes for the synthesis of polycarbonates. Interpretation of the results of various acidity measurements (NH 3 and pyridine desorption, methanol oxidation as a probe reaction) allowed us to identify the catalytic sites as Lewis acid sites.