METHOD FOR PREPARING 4,4'-DICHLORODIPHENYL- SULFONE Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to method for preparing 4,4'- dichlorodiphenylsulfone as a monomer in manufacture of polyarylenesulfones that are thermostable polymers used by structural and insulating designation. Method is carried out by interaction of chlorobenzene with 4-chlorobenzenesulfoacid in the presence of 4-chlorobenzenesulfochloride at 100-165 C in the equimole ratio of reagents up to ceasing hydrogen chloride evolving. Then by-side 4- chlorobenzenesuldoacid is converted to 4-chlorobenzenesulfochloride by reaction with phosphoryl chloride in the mole ratio to the parent 4-chlorobenzenesulfoacid = (0.33-1.1):1 at 140-165 C followed by isolation of 4,4'-dichlorodiphenylsulfone and a mixture of 4-chlorobenzenesulfochloride with 4,4'- dichlorodiphenylsulfone. Mixture of 4-chlorobenzenesulfochloride with 4,4'-dichlorodiphenylsulfone can be fed for synthesis of 4,4-dichlorodiphenylsulfone to the next procedure being without purification. Method allows the significant enhancement the yield of the end product and to exclude formation of 4- chlorobenzenesulfoacid as by-side product. EFFECT: improved preparing method. 4 cl, 3 ex