METHOD OF PREPARING 4,4′-DICHLORODIPHENYL SULFONE Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: method of preparing 4,4′- dichlorodiphenyl sulfone (sulfone) comprises reacting chlorobenzene with chlorosulfonic acid and isolating sulfone from reaction mixture which contains, in addition to sulfone, n-chlorobenzenesulfonic acid. Chlorobenzene is added to reaction mixture resulting from reaction of chlorobenzene with chlorosulfonic acid, the whole is maintained at boiling temperature. Water-chlorobenzene azeotrope is removed using chlorobenzene isolated from azeotrope in said process, p-chlorobenzene sulpochloride is added to the resulting reaction mixture and maintained on heating, and sulfone and p-chlorobenzene sulfonic acid is subsequently isolated from reaction mixture. Said acid is transformed into p-chlorobenzene sulfochloride and is added to reaction mixture resulting from distilling water-chlorobenzene azeotrope. EFFECT: increased yield of the desired product and purity thereof and more efficient preparation method. 5 cl, 3 ex