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. 13, 1983
Filed:
Oct. 26, 1981
William L Evans, Turnersville, NJ (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process for preparing alkylanthrquinones wherein the alkyl group contains from 2 to 5 carbon atoms such as 2-ethylanthraquinone, 2-t-amylanthraquinone or 2-t-butylanthraquinone by ring closure from the corresponding alkylbenzoylvenzoic acid is disclosed. The process involves adding a solution of the alkylbenzoylbenzoic acid to 100% concentrated sulfuric acid or up to 12% oleum, distilling off the solvent at from 20.degree. to 60.degree. C., heating the remaining solution to from 80.degree. to 95.degree. C. and preferably from 83.degree. to 87.degree. C. for 3 to 5 hours, diluting the remaining reaction mixture with water and separating the alkylanthraquinone product.