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:
May. 01, 1990
Filed:
Jan. 23, 1989
Applicant:
Inventors:
Ulrich Eichenauer, Frankfurt, DE;
Peter Neumann, Mannheim, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
568730 ; 568738 ; 568769 ; 568795 ;
Abstract
4,4'-dihydroxybiphenyl is prepared by treating biphenyl-4,4'-disulfonic acid or one of its alkali metal salts in an alkali metal hydroxide melt by a process in which the treatment is carried out in a melt which contains from 7 to 14 moles of potassium hydroxide and from 0 to 8 moles of sodium hydroxide, based in each case on 1 mole of biphenyl-4,4'-disulfonic acid, in the presence of an alkali metal carbonate at from 280.degree. to 360.degree. C.