Transesterification of dimethyl oxalate with phenol over MoO3/SiO2 catalysts

The transesterification of dimethyl oxalate (DMO) with phenol to methyl phenyl oxalate (MPO) and diphenyl oxalate (DPO) was carried out in liquid phase using a variety of solid catalysts. The evaluation results showed that MoO3/SiO2 had a better activity and excellent selectivity to target products compared with many conventional ester exchange catalysts. The effects of supports, loading amount of Mo, catalyst amount and reaction time were investigated. Under catalytic reaction conditions, the total selectivities to methyl phenyl oxalate and diphenyl oxalate were up to 98%. And 49.3% yield of methyl phenyl oxalate and 17.3% yield of diphenyl oxalate were obtained at 453 K in the presence of MoO3/SiO2. A plausible mechanism for the transesterification of dimethyl oxalate with phenol to methyl phenyl oxalate over MoO3/SiO2 was proposed.