Process for the preparation of cyclopropane carboxylic acid esters
US4288387A · kind A · utility
4Cited by
4References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1980 |
| Grant date | Sep 8, 1981 |
| Priority date | — |
| Expiry date | Jun 2, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07H23/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
3-Halogenoethyl- or propyl-2,2-dimethylcyclopropane carboxylic acid esters, which are intermediates in the preparation of synthetic pyrethroids, are prepared by the reaction of certain halogenopentenes or hexenes with a diazoacetic ester in the presence of a catalyst which is metallic copper or a copper (II) salt, a rhodium (II) salt of a carboxylic acid or a transition metal complex of certain chiral Schiff bases. By the use of the latter class of catalysts the yield of preferred cis IR isomer may be increased relative to the other possible isomers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.