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. 21, 1990
Filed:
Apr. 21, 1989
Applicant:
Inventors:
Assignee:
Huels Aktiengesellschaft, Marl, DE;
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
568730 ; 568722 ; 568723 ; 568805 ;
Abstract
Reducing 3,3', 5,5'-tetra-t-butyldiphenoquinone with 2,6-di-t-butylphenol, in the melt, in the presence of a 4-dialkylaminopyridine, and then dealkylating the intermediate formed, in the melt, by adding a phosphorus-containing acid or its derivative provides 4,4'-dihydroxybiphenyl of high purity in high yield.