Synthesis of diphenyl carbonate from phenol and carbon dioxide in carbon tetrachloride with zinc halides as catalyst

Abstract: Synthesis of diphenyl carbonate (DPC) from phenol and CO2 has been explored in CCl4 with zinc halides as catalyst. DPC yield and selectivity are influenced by the catalyst usage, reaction temperature, CO2 pressure and initial composition of reactants. The main byproduct is phenyl salicylate (PS). Zinc halides as Lewis acid exhibit high catalytic activity for DPC synthesis; ZnCl2 gives higher DPC yield and selectivity than ZnBr2 and ZnI2. High DPC yield was obtained with ZnCl2 as catalyst at 120°C and 4.0MPa. Based on the experimental observation, a possible reaction scheme has been proposed. The electronegativity of halogen ligand may determine the formation of DPC and PS; the Cl ligand in ZnCl2 with strong electronegativity may favor the formation of DPC. [Copyright &y& Elsevier]