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. 24, 1984
Filed:
Nov. 05, 1982
Applicant:
Inventors:
Erich Hammerschmidt, Bergisch-Gladbach, DE;
Horst Behre, Odenthal, DE;
Heinz U Blank, Odenthal, DE;
Otto Lindner, Bergisch-Gladbach, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260509 ;
Abstract
The process for preparing 1-amino-2-naphthol-4-sulphonic acid by acidifying 3-oxo-4-hydroxyimino-1,2,3,4-tetrahydronaphthalene-1-sulphonic acid or its alkali metal salt in the presence of hydrogen sulphite is carried out in the presence of iron ions.