Process for the preparation of pure stereoisomers of tetrahydrofolic acid esters salts and tetrahydrofolic acid by fractionated crystallization of tetrahydrofolic acid esters salts
US6858731B1 · kind B1 · utility
2Cited by
8References
16Claims
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Key dates
| Filing date | Jul 12, 2000 |
| Grant date | Feb 22, 2005 |
| Priority date | — |
| Expiry date | Jul 19, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D475/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing and concentrating (6S,αS) or (6S,αR) tetrahydrofolic acid ester salts and (6S,αS) or (6S,αR) tetrahydrofolic acid, characterized by preparing or dissolving equimolar or concentrated mixtures of diastereomers of addition salts of tetrahydrofolic acid esters with aromatic sulphonic acids in organic solvents, followed by crystallizing them at least once, and then if applicable hydrolyzing the crystallizate to produce (6S,αS) or (6S,αR) tetrahydrofolic acid, crystallizing the latter as a free acid or isolating it in the form of a salt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.