Method for preparing phosphinic acids used in preparing ace inhibitors and intermediates produced thereby
US4873356A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1987 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Sep 30, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/3211
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method is provided for preparing phosphinic acid compounds, which are useful in preparing certain angiotensin converting enzyme inhibitors, which have the formula ##STR1## wherein R.sub.1 is lower alkyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl; PA0 R.sub.2 is hydrogen, lower alkyl or arylalkyl; PA0 X is hydrogen, lower alkyl or phenyl; PA0 Y is hydrogen, lower alkyl, phenyl or alkoxy, or together X and Y are --(CH.sub.2).sub.2 --, --(CH.sub.2).sub.3 --, --CH.dbd.CH--, or ##STR2## and n is 0 or 1 including salts thereof and stereoisomers thereof, which method includes the steps of reacting a phosphinic acid ester of the structure ##STR3## wherein R.sub.3 is a group removable by hydrogenolysis such as benzyl or substituted benzyl, with a halo ester of the structure ##STR4## in the presence of an organic base to form a phosphinic acid ester of the structure ##STR5## hydrogenating the above ester to form a diastereomic mixture of a phosphinic acid of the structure ##STR6## recrystallizing to recover the preferred racemic mixture and resolving same employing a resolving agent, preferably L-cinchonidine, to form the corresponding resolved salt which may be acidified to the corre…
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