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:
Aug. 14, 2001
Filed:
May. 19, 1999
Dennis E. Jackman, Prairie Village, KS (US);
Cathy L. Howerton, Independence, MO (US);
Bayer Corporation, Pittsburgh, PA (US);
Abstract
The present invention relates to an improved process for purifying &agr;-keto acids. In particular, the present invention pertains to the isolation of pivalic acid and other organic impurities from &agr;-keto acids. The process of the invention generally includes (i) the partial acidification of an aqueous solution of a sodium salt of the &agr;-keto acid (a“keto salt”), (ii) a first solvent extraction of the keto salt solution to remove organic impurities, (iii) further acidification of the keto salt solution, (iv) a second solvent extraction to remove the &agr;-keto acid, and (v) isolation of the &agr;-keto acid from the solvent. In a preferred embodiment, the present invention relates to the preparation of trimethylpyruvic acid (TMPA) of enhanced purity.