Patent ID: 8022240

Claim:
A process comprising: transesterifying (i) a dialkyl carbonate of the general formula (II): wherein R 1 and R 2 each independently represents a substituent selected from the group consisting of linear or branched, optionally substituted C 1 -C 34 -alkyl groups, and (ii) an aromatic hydroxyl compound of the general formula (III): wherein R, R′ andR″ each independantly represents a substituent selected from the group consisting of hydrogen, linear or branched, optionally substituted C 1 -C 34 -alkyl groups, a C 1 -C 34 -alkoxy groups, C 5 -C 34 -cycloalkyl groups, C 7 -C 34 -alkylaryl groups, C 6 - 34 -aryl groups, halogen radicals, and —COO—R′″ wherein each R′″ independently represents a substituent selected from the group consisting of hydrogen, linear or branched C 1 -C 34 alkyl, C 1 -C 34 -alkoxy, C 5 -C 34 -cycloalkyl, C 7 -C 34 -alkylaryl and C 6 -C 34 -aryl, in the presence of a transesterification catalyst to provide a diaryl carbonate product comprising the transesterification catalyst as an impurity, wherein the diaryl carbonate product comprises a diaryl carbonate of the general formula (I): wherein each R, R′ and R″ is independently defined as above; subjecting the diaryl carbonate product to distillation in a first dividing wall distillation column having an upper part and a lower part, wherein the upper part comprises a rectifying section and the lower part comprises a stripping section; and withdrawing a first sidestream from the first distillation column, wherein the first sidestream comprises a purified diaryl carbonate.