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. 24, 1985
Filed:
Nov. 23, 1983
Applicant:
Inventors:
Tibor Somlo, Birsfelden, CH;
Johann Regli, Birsfelden, CH;
Assignee:
Ciba-Geigy AG, Basel, CH;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260384 ; 260694 ;
Abstract
A process for the preparation of pure bromoanthraquinones by denitrobrominating corresponding nitroanthraquinones is described. The process comprises treating nitroanthraquinones of the formula I ##STR1## wherein X is hydroxy, mercapto, carboxy or halogen and m is 1, 2, 3 or 4 and n is 1 or 2, in the temperature range from 200.degree. to 350.degree. C. Bromoanthraquinones of more than 95% purity are valuable starting materials for dye synthesis and can be used directly without further purification.