Semi-continuous process for the production of 4,4'-dihydroxydiphenylsulfone comprises reaction of phenol with a sulfonating agent and suspension of the resulting crude product in water

摘要

A semi-continuous process for the production of 4,4'-dihydroxydiphenylsulfone comprises reaction of phenol with a sulfonating agent and suspension of the resulting crude product in water at weight ratio of crude product to water of 85:15-55:45 at least 40 deg C, filtering of the product and recycling of the resulting educt- and/or product containing waste stream to the production process. A semi-continuous process for the production of 4,4'-dihydroxydiphenylsulfone comprises: (A) reaction of phenol with a sulfonating agent, (B) suspension of the resulting crude product in water at least 40 deg C which is free of inert organic solvent and optionally contains residual amounts of unreacted phenol, and filtering of the product and (C) recycling of the resulting educt- and/or product containing waste stream to the production process. In step (B) the weight ratio of crude product to water is 85:15-55:45.