摘要 |
<p>A semicontinuous process is provided for the preparation of 4,4'-dihydroxydiphenyl sulfone, comprising the following steps:(a) reaction of phenol with a sulfonating agent,(b) suspension of the resulting crude product in water heated to at least 40° C., which is free of inert organic solvents and can contain residual amounts of unreacted phenol, and filtration of the product, and(c) recycling of the resulting educt-containing and/or product-containing waste streams into the preparative process,wherein, in carrying out step (b), the crude product and water are used in a weight ratio of 85:15 to 55:45.</p> |