Synthesis of diphenyl carbonate from compressed carbon dioxide and phenol without use of organic solvent

Diphenyl carbonate (DPC) was synthesized from CO₂ and phenol catalyzed by Lewis acids. Compressed CO₂ was used as reactant and solvent. It was found that the conversion of phenol and the yield of DPC are dependent on the metal center of Lewis acids, and zinc halides have better catalytic performance than aluminum halides. The reaction of CO₂ with phenol is sensitive to pressure, temperature, and reaction time, and it is improved using triethylamine as acid acceptor. A 31.7% DPC yield was obtained under optimized reaction conditions: 9 MPa at 100 °C for 3 h.