Asymmetric synthesis of piperazic acid and derivatives thereof
US6632942B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2002 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Jun 14, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D237/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention provides a concise, asymmetric synthesis of piperazic acid and derivatives thereof, whereby either the (3S)- or (3R)-enantiomeric form may be obtained with high optical purity. (3S)-piperazic acid is derived from D-glutamic acid through an (R)-2,5-dihydroxyvalerate ester intermediate. After the hydroxy groups are converted to suitable leaving groups, such as mesylates, the ester is treated with a bis-protected hydrazine to provide the desired (3S)-piperazic acid derivative. The (3R) enantiomer of piperazic acid may be similarly obtained starting with L-glutamic acid. The method may also be used to obtain piperazic acid derivatives that have moderate optical purity or are racemic. By this method, piperazic acid derivatives may be obtained that are useful as intermediates for pharmacologically active compounds. For example, certain intermediates of this invention are useful for preparing caspase inhibitors, particularly inhibitors of ICE, through additional steps known in the art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.