Patent ID: 7732629

Claim:
A process for the preparation of a diaryl carbonate by transesterification of an aromatic alcohol with a dialkyl carbonate in the presence of a transesterification catalyst during a period of time [t a ], in which the aryl moiety is selected from unsubstituted phenyl and mono-, di- and trisubstituted phenyl groups, in which the alkyl moiety is selected from C 2 to C 4 linear and branched alkyl groups, in which the catalyst concentration is designated [c a ], expressed as gram catalyst per gram of aromatic alcohol and dialkyl carbonate, in which the period of time [t m ] and catalyst concentration [c m ] are determined to arrive at a pre-set approach to the equilibrium for the transesterification of the aromatic alcohol with dimethyl carbonate to methyl aryl carbonate and methanol, in which the product [c a ]*t a is at least 1.5*[c m ]*t m , under otherwise the same reaction conditions.