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:
Oct. 02, 1984
Filed:
Jan. 31, 1983
Billy L Keel, Arnold, MO (US);
Irvin S Klaus, St. Louis, MO (US);
Marvin L Oftedahl, Warson Woods, MO (US);
Monsanto Company, St. Louis, MO (US);
Abstract
A process for increasing the color-free shelf life of a crude N-acetyl aminophenol prepared by the acetylation of an aminophenol wherein the N-acetyl aminophenol contains color-forming impurities which are the products of oxidation of the aminophenol and other side reactions. The process comprises dissolving the crude N-acetyl aminophenol in a solvent containing a reducing agent, heating the solution at about the boiling point, crystallizing the N-acetyl aminophenol from the solution, washing the crystalline N-acetyl aminophenol with solvent containing reducing agent and thereafter separating and drying the crystalline N-acetyl aminophenol.