Process for the preparation of enantiomerically-enriched cyclopropylalanine derivates
US6635784B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2001 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Sep 20, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07B2200/07
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Disclosed are processes for the preparation of enantiomerically-enriched cyclopropylalanine derivatives by the hydrogenation of certain enamides in the presence of a catalyst comprising a transition metal and a substantially enantiomerically-pure bis-phosphine catalyst and certain novel enamide ester compounds which are intermediates in the processes. The processes include novel 2-step and 3-step processes for the preparation of enantiomerically-enriched cyclopropylalanine derivatives. The two-step process comprises the steps of reacting cyclopropanecarboxaldehyde with a substituted phosphorylglycine to afford an enamide ester which then is hydrogenated in the presence of a catalyst comprising a transition metal and a substantially enantiomerically-pure bis-phosphine catalyst. The three-step process comprises the steps of forming an azlactone from an N-acylglycine and cyclopropanecarboxaldehyde, converting the azlactone to the aforesaid enamide which then is hydrogenated in the presence of a catalyst comprising a transition metal and a substantially enantiomerically-pure bis-phosphine catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.