PRODUCTION OF DIARYL CARBONATE

PROBLEM TO BE SOLVED: To readily produce a diaryl carbonate useful as a raw material for producing a polycarbonate at a sufficient rate of reaction by using a diaryl oxalate as a raw material with out using strongly toxic phosgene. SOLUTION: A diaryl oxalate is heated in the presence of an oxide of an alkaline earth metal in the vapor phase in a reactor to carry out the decarbonylating reaction. For example, diphenyl oxalate is cited as the diaryl oxalate and an oxide of magnesium, calcium, etc., is preferred as the oxide of the alkaline earth metal. The oxide may be supported on a catalyst carrier such as alumina, silica or active carbon for use. The decarbonylating reaction is preferably carried out under conditions of 200-600 deg.C, preferably about 300-500 deg.C and 10-10,000hr , preferably about 50-5,000hr space velocity by feeding a raw material gas containing an inert gas such as N2 gas to the reactor.