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US 5,288,913 AGranted
Process for the preparation of 4,4'-dihydroxydiphenyl sulfone
AssigneeHoechst Aktiengesellschaft
InventorGeorg Grotsch
Life of this patent
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Abstract
Process for the preparation of 4,4'-dihydroxydiphenyl sulfone in a high yield and high purity by reaction of phenol with a sulfonating agent in a chlorinated aromatic, in which phenol is reacted with a sulfonating agent in ortho-, meta- or para-chlorotoluene or in any desired mixture of these isomeric chlorotoluenes as the inert solvent, at temperatures of from about 100.degree. to about 200.degree. C.
Claims15
A process for the preparation of 4,4'-dihydroxydiphenyl sulfone in a high yield and high purity by reaction of phenol with a sulfonating agent, said process comprising:
- carrying out the reaction between phenol and the sulfonating agent in a liquid reaction medium comprising an inert solvent consisting essentially of about 50 to about 200% by weight, based on the amount of 4,4'-dihydroxydiphenylsulfone to be expected in theory, of ortho-, meta- or parachlorotoluene or a mixture of said chlorotoluenes, at a temperature of from about 100.degree. to about 200.degree. C., and removing the water formed by the reaction continuously from circulation with the chlorotoluene in the reaction medium, until the 4,4'-dihydroxydiphenyl sulfone crystallizes out of the reaction medium, then separating said 4,4'-dihydroxydiphenyl sulfone from the liquid reaction medium.
Dependencies are inferred from the claim text.