Separation of enantiomers of chiral carboxylic acids
US4337352A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1981 |
| Grant date | Jun 29, 1982 |
| Priority date | — |
| Expiry date | May 15, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/487
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the separation of enantiomers of a chiral carboxylic acid, comprising reacting an alkali metal salt of the acid with an amount of an optically active amine salt which is equivalent to only one enantiomer, in an aqueous weakly alkaline buffered solution as the reaction medium, the reaction medium having a pH value at which the entire acid is present in the ionized form but at which no amine salt is yet deprotonated. Advantageously the carboxylic acid is of the formula ##STR1## wherein R.sup.1 and R.sup.2 each independently is hydrogen, alkyl, with 1-4 C atoms, halogen, optionally substituted phenyl or optionally substituted phenylmercapto, the optically active amine salt is a mineral acid salt of a phenylglycine alkyl ester, .alpha.-methylbenzylamine, phenylethylamine, phenylethanolamine, 1-phenyl-2-dimethyl-amino-1,3-propanediol or abietylamine, the buffered solution contains potassium carbonate, sodium carbonate, sodium bicarbonate or sodium hydrogen phosphate as the buffering agent, and the reaction is effected at about 0.degree. to 100.degree. C., the process including the further steps of separating the precipitated ammonium salt from the alkali metal salt that re…
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