Process for the preparation of cyclopropylacetylene
US6288297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1999 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Sep 30, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates generally to novel methods for the synthesis of cyclopropylacetylene which is an essential reagent in the asymmetric synthesis of (S)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-ben zoxazin-2-one; a useful human immunodeficiency virus (HIV) reverse transcriptase inhibitor. In the process, for example, cyclopropane carboxaldehyde is alkylated to form 1,1,1-trichloro-2-cyclopropyl-ethanol; which in turn is hydroxy protected to form 1,1,1-trichloro-2-cyclopropylethyltosylate; which in turn undergoes elimination to form cyclopropyl acetylene. This improvement provides for high conversion of inexpensive, readily available starting materials into cyclopropylacetylene, high overall yields and can be conducted on an industrial scale.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.