Process for purifying .alpha.-keto acids
US6274766A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1999 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | May 19, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to an improved process for purifying .alpha.-keto acids. In particular, the present invention pertains to the isolation of pivalic acid and other organic impurities from .alpha.-keto acids. The process of the invention generally includes (i) the partial acidification of an aqueous solution of a sodium salt of the .alpha.-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 .alpha.-keto acid, and (v) isolation of the .alpha.-keto acid from the solvent. In a preferred embodiment, the present invention relates to the preparation of trimethylpyruvic acid (TMPA) of enhanced purity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.