Patent · US Expired

Isolation of 4,4'-dichlorodiphenyl sulfone

US4873372A · kind A · utility

2Cited by

3References

6Claims

0Family size

Assignee

BASF SE

Inventors

Gerhard Schaefer · Heidelberg, DE
Heinz Eilingsfeld · Bischofswerda, DE
Peter Neumann · Wiesloch, DE
Michael Stumpp · Deidesheim, DE

Key dates

Filing date	Jan 25, 1988
Grant date	Oct 10, 1989
Priority date	—
Expiry date	Jan 25, 2008

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C317/00
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

A process for the isolation of 4,4'-dichlorodiphenyl sulfone from a mixture of dichlorodiphenyl sulfones in which the ratios of the masses of 2,4'-dichlorodiphenyl sulfone and 3,4'-dichlorodiphenyl sulfone to the mass of 4,4'-dichlorodiphenyl sulfone are respectively from 0.5% to 20% and from 0.5% to 30% by treating the mixture with an alkanol at temperatures of from 20.degree. C. to 250.degree. C., cooling, and separating the pure 4,4'-dichlorodiphenyl sulfone that precipitates.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.