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:
Jul. 14, 1981
Filed:
Jan. 10, 1980
Applicant:
Inventors:
Helmut Seidler, Bonn, DE;
Gunter Gehrke, Cologne, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260383 ; 260378 ;
Abstract
Dimethoxyanthraquinones can be prepared in high purity and in good yield in an economic manner which does not pollute the environment when 1 part by weight of dinitroanthraquinone is reacted with 2-8 parts by weight of methanol and 0.5-1.5 parts by weight of potassium hydroxide until all of the nitro groups have been replaced; the reaction is preferably carried out in the presence of 0.05-0.5 part by weight of amidosulphonic acid.