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:
Jun. 07, 1983
Filed:
May. 30, 1979
Applicant:
Inventor:
Reinold Schmitz, Odenthal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C09B / ;
U.S. Cl.
CPC ...
260383 ;
Abstract
A process, which does not pollute the environment, for the preparation of quinizarin consists in reacting a mixture of phthalic anhydride p-chlorophenol, sulphuric acid and boric acid or boric anhydride at elevated temperatures in such a way that, in the reaction mixture, there is sulphuric acid preferably containing 10-20% of free SO.sub.3 and the weight ratio of p-chlorophenol to the total amount of H.sub.2 SO.sub.4 +SO.sub.3 is 1:1.5 to 4.0. Yields and purity of the product are outstanding, despite the concentrated procedure.