Process for preparing (trans)-4-substituted-dl-proline derivatives
US4937355A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Jun 26, 1990 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is provided for preparing (trans)-4-phenyl-DL-proline derivatives, which are useful in preparing certain angiotensin converting enzyme inhibitors, which process involves reacting an ester of the structure ##STR1## wherein X is a leaving group such as tosylate, R.sup.3 is lower alkyl, R is cyclohexyl, phenyl or substituted phenyl, and R.sup.1a is a protecting group, with a potassium amide base such as potassium hexamethyldisilazide under reduced temperatures to form the trans-4-substituted proline ester derivative of the structure ##STR2## then hydrolyzing the proline ester to the acid of the structure ##STR3## and removing the R.sup.1a nitrogen protecting group to form the unprotected acid of the structure ##STR4##
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.