Process for the optical resolution of DL-p-hydroxy-phenylglycine
US4309362A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1978 |
| Grant date | Jan 5, 1982 |
| Priority date | — |
| Expiry date | Mar 13, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07B2200/07
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Seed crystals of an optically active enantiomer of any one of p-hydroxyphenylglycine benzenesulfonate, p-hydroxyphenylglycine p-ethylbenzenesulfonate, p-hydroxyphenylglycine o-toluenesulfonate or p-hydroxyphenylglycine sulfosalicylate are added to a supersaturated solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt. Crystallization of the optically active enantiomer results. Then, the crystals are recovered. Alternatively, crystals of the optically active enantiomer may be added to a hot solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt to produce a supersaturated solution thereof. The solution is then cooled to crystallize out the optically active enantiomer. Optically active p-hydroxyphenylglycine benzenesulfonate, optically active p-hydroxyphenylglycine p-ethylbenzenesulfonate, optically active p-hydroxyphenylglycine o-toluenesulfonate or optically active p-hydroxyphenylglycine sulfosalicylate is thereby obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.