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. 13, 1992
Filed:
Jul. 20, 1990
John R Fritch, Corpus Christi, TX (US);
O Stanley Fruchey, Bad Soden/T.S., DE;
Theodore Horlenko, Corpus Christi, TX (US);
Daniel A Aguilar, Corpus Christi, TX (US);
Charles B Hilton, Corpus Christi, TX (US);
Phillip S Snyder, Rock Hill, SC (US);
William J Seeliger, Corpus Christi, TX (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
N-acetyl-para-aminophenol is prepared by contacting 4-hydroxyacetophenone oxime with a Beckmann rearrangement catalyst in an alkyl alkanoate reaction solvent. An integrated process is disclosed wherein 4-hydroxyacetophenone is reacted with a hydroxylamine salt and a base to obtain 4-hydroxyacetophenone oxime, the oxime product is extracted from the resulting reaction mixture with a substantially water-immiscible solvent, and the mixture of oxime and substantially water-immiscible solvent is contacted with a Beckmann rearrangement catalyst to produce N-acetyl-para-aminophenol. Novel Beckamnn rearrangement catalysts are used to limit by-product formation in the ester solvent.