METHOD OF SYNTHESIS OF 4,4'-DICHLORODIPHENYL-SULFONE Russian patent published in 2002 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to a method of synthesis of 4,4'-dichlorodiphenylsulfone that is a monomer used in synthesis of thermostable polyarylenesulfone polymers. Method involves the interaction of chlorosulfonic acid with chlorobenzene excess at 20-60 C, addition of 4-chlorobenzene sulfochloride to a mixture in the mole ratio = (0.39-0.49) : 1 to the parent chlorobenzene and mixture is kept at 145-165 C up to hydrogen chloride evolving ceasing. The formed 4-chlorobenzene sulfoacid is converted to 4-chlorobenzene sulfochloride by effect with chlorosulfonic acid taken in the mole ratio = (0.75-1.24) : 1 to the parent chlorobenzene at 20-80 C followed by isolation of 4,4'-dichlorodiphenylsulfone and 4-chloro- -benzene sulfochloride melt containing up to 35 wt.-% of 4,4'-dichloro- -diphenylsulfone. 4-Chlorobenzene sulfochloride melt can be fed to the synthesis of 4,4'-dichlorodiphenylsulfone on the next stage without purification. Method ensures to diminish amount of technological stages of process and exclude the formation of inorganic salt waste. EFFECT: improved method of synthesis. 5 cl, 2 tbl