Abstract: In this paper,4,4'-dichlorodiphenylsulfone,4,4'-dihydroxyldiphenylsulfone and4-chloro-4'-hydroxyldiphenylsulfone were separated completely by HPLC. From the rela-tions between the reacting conditions and yields of 4-chloro-4'-hydroxyldiphenylsulfone byhydrolysis of 4,4'-dichlorodiphenylsulfone,it was found that the larger the amount of NaOHand the higher the temperature, the faster the hvdrolvsis and the lower the yield. Theamount of the by product 4,4'-dihydroxyldiphenylsulfone increases with reaction time. Af-ter the highest point the yield of 4-chloro-4' hydroxyldiphenylsulfone decreases as increase ofby-product. The optimum hydrolysis conditions are: 135～140℃, NaOH/4,4'-di-chlorodiphenylsulfone=3. 25 :1(molar ratio), reaction time 2,5～3. 0h. The yield wasabove 90%. The condensation polymerization occurred in the hydrolysis and the purificationof product also has been disctissed.

Key words: dichlorodiphenylsulfone, chlorohydroxyldiphenylsulfone, hvdrolysis, HPLC