Process for the preparation of cyclopropylacetylene
US6049019A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1998 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Jul 30, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/04
- 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, cyclopropane carboxaldehyde is condensed with malonic acid to form 3-cyclopropylacrylic acid; 3-cyclopropylacrylic acid is halogenated to form (E,Z)-1-halo-2-cyclopropylethylene; and (E,Z)-1-halo-2-cyclopropylethylene is dehydrohalogenated 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.