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. 15, 1979
Filed:
Jun. 20, 1978
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
260380 ; 260689 ;
Abstract
A process for the preparation of 1-amino-8-nitro-4,5-dihydroxyanthraquinone by partially reducing the corresponding dinitrohydroxyanthraquinone and isolating the reduction product, in which crude 1,8-dinitro-4,5-dihydroxyanthraquinone obtained by nitrating 4,5-dihydroxyanthraquinone is partially reduced in a phenol-water mixture, which contains from 5 to 50% by weight of water, in the presence of an alkali metal phenolate, by means of a reductone, reductonate or a mixture of these. The product is virtually free from by-products and is suitable for use for the synthesis of dyes.