Continuous process for the preparation of (S)-2-acetyloxypropionic acid chloride
US9926257B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2013 |
| Grant date | Mar 27, 2018 |
| Priority date | — |
| Expiry date | Dec 4, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a continuous method for the preparation of (S)-2-acetyloxypropionic acid from an aqueous solution of lactic acid and acetic anhydride, in acetic acid. (S)-2-acetyloxypropionic acid is used for the preparation of (S)-2-acetyloxypropionic acid chloride, an essential intermediate compound for the preparation of lopamidol and has to be industrially produced with high purity and suitable quality for producing lopamidol according to the Pharmacopoeia requirements. The continuous process according to the invention, comprises therefore also the chlorination steps of (S)-2-acetyloxypropionic acid with thionyl chloride to give the corresponding (S)-2-acetyloxypropionic acid chloride which is further distilled to give the suitable purity characteristics for its use for the preparation of non-ionic iodinated contrast agents as lopamidol.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.