| 摘要 |
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.
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