The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 30, 1994
Filed:
Jun. 22, 1990
Applicant:
Inventors:
Stephen P Brugge, Naperville, IL (US);
Juergen K Holzhauer, Naperville, IL (US);
Thomas E Wolff, Lisle, IL (US);
Assignee:
Amoco Corporation, Chicago, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549241 ; 549248 ; 562412 ; 562413 ; 562414 ;
Abstract
A process for making relatively high purity eulfonylbis(phthalic anhydride) is provided. 3,3',4,4'-tetramethyl diphenyl sulfone is catalytically oxidized in a solvent under liquid phase elevated temperature and pressure conditions. The catalyst is constituted by cobalt, manganese, zirconium, and bromine. Sulfonylbis(phthalic) acid is recovered by crystallization and is then heated to produce the anhydride. Preferably, the acid is purified prior to dehydration.