US4138584A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of chrysanthemic acid esters and homologues thereof
Assignee: Cheminova AS
•
Filing: 1977-05-23
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Granted: 1979-02-06
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Expires: 1997-05-23
Abstract
Abstract A three-step process for the production of chrysanthemic acid esters and their homologues of the formula: ##STR1## in which R 1 and R 2 are hydrogen or C 1 -C 6 alkyl, R 3 and R 4 are C 1 -C 6 alkyl or halogen or, together with the C atom to which they are attached, form a cycloalkyl group, and R 5 is C 1 -C 6 alkyl, Which comprises: (1) decarboxylating a lactone of the formula: ##STR2## (2) treating the resulting decarboxylated lactone to effect ring cleavage, halogenation and esterification to form an ester of the formula: ##STR3## in which X is Cl, Br or I, and (3) TREATING THE ESTER X with a base to effect internal condensation whereby the desired product of formula I is obtained. The esters I are valuable intermediates for the preparation of synthetic pyrethroids having insecticidal activity.
Inventors
- 👤 Per D. Klemmensen
- 👤 Hans Kolind-Andersen
- 👤 Hans B. Madsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:43
CPC Classifications
C; C07; C07C; C07C61/00; C07C61/16; C07C61/20; A; A01; A01N; A01N53/00; C07C61/04; C07C2601/00; C07C2601/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
210 words
A process for the preparation of chrysanthemic acid esters and their homologues of the formula: ##STR11## wherein R 1 and R 2 are individually selected from the group consisting of hydrogen and alkyl groups having 1 to 6 carbon atoms, R 3 is a halogen atom; R 4 is a halogen atom; and R 5 is an alkyl group having 1 to 6 carbon atoms, which comprises the steps of: (1) heating a lactone of the formula: ##STR12## in which R 1 , R 2 , R 3 , R 4 and R 5 have the above stated meanings, to a temperature of from about 100° C. to about 200° C. in the presence of water and an inert solvent to effect decarboxylation and to obtain a lactone of the formula: ##STR13## (2) reacting the lactone IX with thionyl chloride and with an aliphatic alcohol R 5 OH, wherein R 5 has the above-stated meaning, at a superatmospheric pressure to bring about, in the same reaction mixture, ring cleavage, halogenation and esterification without isolating any intermediate product, whereby there is obtained an ester of the formula: ##STR14## (3) treating the ester X with a base to effect dehydrohalogenation and internal condensation whereby the desired compound of formula I is obtained.
Claim 2
Dependent Claim
210 words
A process for the preparation of chrysanthemic acid esters and their homologues of the formula: ##STR11## wherein R 1 and R 2 are individually selected from the group consisting of hydrogen and alkyl groups having 1 to 6 carbon atoms, R 3 is a halogen atom; R 4 is a halogen atom; and R 5 is an alkyl group having 1 to 6 carbon atoms, which comprises the steps of: (1) heating a lactone of the formula: ##STR12## in which R 1 , R 2 , R 3 , R 4 and R 5 have the above stated meanings, to a temperature of from about 100° C. to about 200° C. in the presence of water and an inert solvent to effect decarboxylation and to obtain a lactone of the formula: ##STR13## (2) reacting the lactone IX with thionyl chloride and with an aliphatic alcohol R 5 OH, wherein R 5 has the above-stated meaning, at a superatmospheric pressure to bring about, in the same reaction mixture, ring cleavage, halogenation and esterification without isolating any intermediate product, whereby there is obtained an ester of the formula: ##STR14## (3) treating the ester X with a base to effect dehydrohalogenation and internal condensation whereby the desired compound of formula I is obtained.
Claim 3
Dependent Claim
39 words
A process as set forth in claim 1, wherein the inert solvent used in step (1) is selected from the group consisting of dimethyl sulphoxide, dimethyl formamide, hexamethylphosphoric triamide, N-methyl-2-pyrrolidone and methanol and mixtures of at least two thereof.
Claim 4
Dependent Claim
20 words
A process as set forth in claim 1, wherein step (2) is carried out in the absence of a catalyst.
Claim 5
Dependent Claim
23 words
A process as set forth in claim 1, wherein step (2) is carried out in the presence of a Lewis acid as catalyst.
Claim 6
Dependent Claim
15 words
A process as set forth in claim 4, wherein the catalyst is FeCl 3 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |