反应详情

According to DE-A-2,708,388, the reaction of phenol with sulfuric acid in the presence of a solvent, e.g. of an aromatic hydrocarbon, gives bis(4-hydroxyphenyl)sulfone and the isomeric 2,4,-dihydroxydiphenylsulfone in a ratio of about 3:1. In addition, as our own experiments have shown, a small amount of 6-hydroxy[1,3-bis(4-hydroxyphenylsulfonyl)]benzene is formed. The yield and purity of the target product are improved by continuously removing the solvent from the reaction by distillation or by distilling off the product after the reaction has been substantially completed, it being important to carry out the distillation in the temperature range of 160°-200° C., since only under these conditions is isomerization of the 2,4'-isomer to bis(4-hydroxyphenyl)sulfone achieved.