Process for the preparation of chiral 4-aryloxyazetidinones
US5310899A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D205/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing a single enantiomer of a 4-aryloxyazetidin-2-one derivative in optically pure form comprises reacting a hindered vinyl ester with chlorosulphonyl isocyanate; displacing the hindered acyloxy group with a phenolic derivative containing a protected carboxy group; deprotecting the carboxylate moiety; resolving with a chiral amine; filtering; and regenerating the desired enantiomer by acidification. A method for enriching the product obtained from the acyloxy displacement step in favour of the desired enantiomeric form, by treating with an asymmetric catalyst such as a chiral alkaloid derivative, is provided; as also is a method for racemising the unwanted antipode of the desired 4-aryloxyazetidin-2-one enantiomer. The invention further provides novel enantiomers based on the 4-aryloxyazetidin-2-one ring structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.