Abstract: A method of producing a purified ester-substituted phenol stream is provided. The method includes a first step of obtaining from a melt transesterification reaction a byproduct stream containing a residual ester-substituted diaryl carbonate, an ester-substituted phenol, a residual melt transesterification catalyst, and a catalyst degradation product. A second step includes treating the reaction byproduct stream to separate ester-substituted phenol and catalyst degradation product from residual ester-substituted diaryl carbonate and residual melt transesterification catalyst to create a light recycle stream containing ester-substituted phenol and catalyst degradation product and a heavy recycle stream containing residual ester-substituted diaryl carbonate and residual melt transesterification catalyst. A third step includes treating the light recycle stream to reduce catalyst degradation product concentration thereby producing a purified ester-substituted phenol stream.