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:
Jan. 05, 1993
Filed:
May. 23, 1991
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562 87 ; 562 85 ; 562 88 ; 25230121 ;
Abstract
Sulphonic acids of bis-styrylbiphenyls, which are useful optical brighteners, are obtained in good yields in a simple manner by reacting styrene compounds with 4,4'-dibromobiphenyl-3,3'-disulphonic acids or their salts in the presence of bases and palladium catalysts. The bis-stilbene compounds have the formula: ##STR1## where at least one of the rings A or B contains a sulfonic acid group.