Process for the stereospecific synthesis of azetidinones
US6093812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1994 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Jan 7, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F7/1892
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention provides an improved process for producing azetidinones. More particularly, this invention provides the steps of producing an trans-azetidinone represented by the formula ##STR1## from a carboxylic acid R.sup.2 --D--CH.sub.2 COOH, an aldehyde R.sup.1 --A--CHO and an amine RNH.sub.2, by the steps of: (a1) converting a carboxylic acid to the corresponding acid chloride; (b1) deprotonating a chiral oxazolidinone and treating the resulting anion with the product of step (a1); (c1) enolizing the product of step (b1) and condensing with the aldehyde; (d1) hydrolyzing the product of step (c1); (e1) condensing the product of step (d1) with the amine; and (f1) cyclizing the product of step (e1). Alternatively, the process comprises (a2) enolizing the product of step (b1) and condensing, in the presence of a Lewis acid, with a Schiff's base prepared from the aldehyde and the amine; and (b2) cyclizing the product of step (a2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.