Patent US4551281A successfully refreshed from Google Patents.
US4551281A
Expired / Lapsed
US
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Process for the preparation of cyclopropane carboxylic acid esters
Assignee: Syngenta Ltd
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Filing: 1984-08-27
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Granted: 1985-11-05
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Expires: 2004-08-27
Abstract
Abstract 3-(2'-chloro-3',3',3'-trifluoropropenyl)-2,2-dimethylcyclopropane-1-carboxylic acid esters are prepared by dehydrohalogenation of the corresponding 3-(2',2'-dichloro-3',3',3-trifluoropropyl) compounds by reaction with an alkali metal carbonate in a polar aprotic solvent. The products are intermediates in the preparation of pyrethroid insecticides or are themselves insecticides.
Inventors
- 👤 John Crosby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:50
CPC Classifications
C; C07; C07C; C07C253/00; C07C253/30; C07C67/00; C07C67/30; C07C67/317; C07C2601/00; C07C2601/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
A process for the preparation of a cyclopropane carboxylic acid ester having the general formula: ##STR5## wherein R is a lower alkyl, m-phenoxybenzyl, α-cyano-m-phenoxybenzyl or α-ethynyl-m-phenoxybenzyl group, which comprises reacting a compound having the general formula: ##STR6## wherein R has the meanings stated above, with an alkali metal carbonate in a polar aprotic solvent, the alkali metal carbonate being selected from the group consisting of sodium carbonate and potassium carbonate.
Claim 2
Dependent Claim
70 words
A process for the preparation of a cyclopropane carboxylic acid ester having the general formula: ##STR5## wherein R is a lower alkyl, m-phenoxybenzyl, α-cyano-m-phenoxybenzyl or α-ethynyl-m-phenoxybenzyl group, which comprises reacting a compound having the general formula: ##STR6## wherein R has the meanings stated above, with an alkali metal carbonate in a polar aprotic solvent, the alkali metal carbonate being selected from the group consisting of sodium carbonate and potassium carbonate.
Claim 3
Dependent Claim
31 words
A process as claimed in claim 1 wherein the amount of alkali metal carbonate which is used is from 1 to 20 mols per mol of the compound of formula (II).
Claim 4
Dependent Claim
31 words
A process as claimed in claim 1 wherein the amount of alkali metal carbonate which is used is from 1 to 5 mols per mol of the compound of formula (II).
Claim 5
Dependent Claim
31 words
A process as claimed in claim 1 wherein the amount of polar aprotic solvent which is used is from 3 to 200 mols per mol of the compound of formula (II).
Claim 6
Dependent Claim
31 words
A process as claimed in claim 1 wherein the amount of polar aprotic solvent which is used is from 5 to 20 mols per mol of the compound of formula (II).
Claim 7
Dependent Claim
17 words
A process as claimed in claim 1 wherein the reaction temperature is from 50° to 250° C.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 1 wherein the reaction temperature is from 100° to 200° C.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |