Process for the production of r(+)&agr;-lipoic acid
US6670484B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2003 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Apr 9, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C319/06
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for the synthesis of R(+)&agr;-lipoic acid comprising the following stages: a) Salifying of racemic thioctic acid with R(+)&agr;-methylbenzylamine; b) separation by filtration of the crystallized diastereoisomeric salt of R(+)&agr;-lipoic acid-R(+)&agr;-methylbenzylamine; c) purification by re-crystallization of the diastereoisomeric salt of R(+) &agr;-lipoic acid-R(+)&agr;-methylbenzylamine, in which the re-crystallization solvent consists of a mixture of non-polar/polar solvents; d) separation of the diastereoisomeric salt to obtain R(+)&agr;-lipoic acid by reaction of said salt with acids selected from the group consisting of aliphatic hydroxy-carboxylic acids having 3 to 6 carbon atoms and aqueous phosphoric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.