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:
Sep. 01, 1992
Filed:
Sep. 23, 1991
Applicant:
Inventors:
Erwin Hahn, Heidelberg, DE;
Udo Mayer, Frankenthal, DE;
Friedrich-Wilhelm Raulfs, Limburgerhof, DE;
Ulrike Schloesser, Mannheim, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07B / ;
U.S. Cl.
CPC ...
562 49 ;
Abstract
J-Acid urea of the formula ##STR1## is prepared by reacting 7-amino-4-hydroxynaphthalene-2-sulfonic acid (J-acid) with urea at from 100.degree. to 140.degree. C. under a pressure ranging from atmospheric pressure to 10 bar in an inert solvent to a partial extent, precipitating unconverted J-acid in an acidic medium and separating it off, and, if desired, isolating J-acid urea from the resulting neutralized solution by salting out.