JPS5933580B2 - Method for producing γ-unsaturated carboxylic acid ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula R or phenyl group.

) The present invention relates to a method for producing a γ-unsaturated carboxylic acid ester represented by: More specifically, the present invention is directed to the general formula □ - (■) (wherein R2, R3, R4 and R5 are the same as described above) under non-catalytic conditions.

cycloalkyl group or phenyl group, R5 is hydrogen,
A lower alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or a phenyl group. ) by reacting an allyl alcohol derivative represented by the general formula (1) with an orthocarboxylic acid ester represented by the general formula (wherein R is hydrogen or a lower alkyl group, and R1 is a lower alkyl group). ) The present invention relates to a method for producing a γ-unsaturated carboxylic acid ester represented by: The γ-monounsaturated carboxylic acid ester represented by the general formula (1) is useful as an intermediate for the synthesis of units constituting the acid moiety of synthetic pyrethroid compounds, which are attracting attention for their usefulness as insecticides. Conventionally, D. D. T
．． YaB. H. C. However, due to its residual toxicity, there is a strong demand for non-polluting insecticides. From this point of view, pyrethroids, which have been extracted from natural products and used since ancient times, are attracting new attention due to their low pollution and insecticidal ability. The disadvantage of using natural pyrethroid insecticides is that they biodegrade quickly. As a result of a thorough search for a compound that solves this drawback and has insecticidal efficacy superior to that of natural pyrethroids, a derivative of chrysanthemum acid with a modified dimethylvinyl group has been shown to have a long-lasting and excellent insecticidal effect. A synthetic pyrethroid was discovered. CM.
EllOtretal. , Nature, 244, 4
56 (1973)] The present invention provides a method for producing the γ-monounsaturated carboxylic acid ester represented by the general formula (1), which is useful as a precursor of the cyclopropane carboxylic acid ester for synthetic pyrethroids. be.

(See Reference Examples below) Conventionally, in order to convert the dimethylvinyl group of chrysanthemum acid, a method has been proposed in which chrysanthemum acid itself is used as a starting material and a new substituent is introduced after ozonolysis.

However, this conventional method has drawbacks such as the use of expensive chrysanthemum acid and the long and complicated synthesis route. [Unexamined Japanese Patent Publication No. 1973
-47531 and D. G. BrOwnetal. , J.
．． Agr. FOOdChem. , Dan, 767 (1973
)reference〕. Furthermore, as a conventional method for producing γ-unsaturated carboxylic acid esters, a method has been proposed in which 3-methylcrotyl alcohol and vinyl ether are condensed, and the resulting γ-unsaturated aldehyde is oxidized and esterified [
J. Arrl. Chem. SOc. , 82, 4681-
5 (1960)).

However, this conventional method not only requires relatively expensive reagents such as vinyl ether, but also requires a long reaction process, making it difficult to adopt as an industrial method.

In order to solve such drawbacks, the present inventors have made extensive studies and have completed a general method for producing γ-unsaturated carboxylic acid esters that can be industrially advantageously led to chrysanthemum acid analogues. It has been reached.

The general formula () used as a raw material compound in the method of the present invention
Allyl alcohol derivatives represented by include 3-methyl-2-buten-1-ol, 4-methyl-3-benzen-2-ol, 2,4-dimethyl-3-benzene-2
-ol, 5-methyl-4-hexen-3-ol, 2
-Methyl-2-hepten-4-ol, cinnamyl alcohol, etc. can be exemplified. All of these allyl alcohol derivatives are compounds that are easily available as industrial raw materials. Examples of the orthocarboxylic acid ester which is the other starting material include orthoesters of alkylcarboxylic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, and valeric acid. All of these compounds can be easily produced by alcoholysis of the corresponding nitrile derivatives. Reaction solvents are not necessarily required, but include n-octane, toluene, o-m-p-xylene, di-n-butyl ether, t-butyl alcohol,
A substance that does not participate in the reaction, such as N·N-dimethylformamide, can be used.

Although the reaction temperature is not limited, it is preferably in the range of about 100 to 250°C from the viewpoint of reaction rate and selectivity.

The present invention will be explained in more detail below using Examples and Reference Examples. Example 1 Mix 4.3y of 3-methyl-2-buten-1-ol and 8.1y of ethyl orthoacetate, gradually heat the oil bath,
The temperature was brought to 165° C. over a period of 2 hours.

The mixture was heated and stirred at 165° C. for an additional 26 hours.

Ethanol produced as the reaction progressed was distilled out of the reaction system. After cooling, the product was diluted with ether and thoroughly shaken with 1N hydrochloric acid to decompose the remaining orthoester. Next, it was washed with 5% sodium bicarbonate solution and water, and then dried.
After concentrating the solution, distill it under reduced pressure to a boiling point of 80-85℃/52m
4.03y of ethyl 3,3-dimethyl-4-benzenate having mHg was obtained. Yield 52%.

Nuclear magnetic resonance absorption spectrum (CCl4, δ) of the product Example 2 3.617 of 2-buten-1-ol and 9.667 of ethyl orthopropionate were mixed and heated in an oil bath to 6.5
It was heated from room temperature to 165° C. for an hour.

The mixture was further heated and stirred at 165° C. for 20 hours. The ethanol produced during this time was distilled off. Thereafter, the same operation as in Example 1 was carried out, and the boiling point was 90-95°C/65°C by vacuum distillation.
5.217 ethyl 2,3-dimethyl-4-benzenate with mmHg was obtained. Yield 67%. Nuclear magnetic resonance absorption spectrum (CCl4, δ) of the product Example 3 2.687 g of cinnamic alcohol and 3.52 g of ethyl orthoacetate were mixed and heated to 165° C. for 5.5 hours while gradually heating the oil bath. And so.

The mixture was further heated and stirred at 165° C. for 13 hours. Thereafter, the same operation as in Example 1 was carried out to obtain a boiling point of 88-88 by distillation under reduced pressure.
2.817 ethyl 3-phenyl-4-benzenate was obtained having a temperature of 9° C./1.2 mmHg. Yield 69% o Nuclear magnetic resonance absorption spectrum (CCl4, δ) of product Example 44-Methyl-3-benzen-2-ol 57 and ethyl orthoacetate 107 were mixed and heated in an oil bath for 6.5 hours. Once heated from room temperature to 165°C.

The mixture was further heated and stirred at 165°C for 22 hours. The ethanol produced during this time was distilled off. After cooling, the product was diluted with ether and thoroughly shaken with 1N hydrochloric acid to decompose the remaining orthoester. Next, it was washed with 5% sodium bicarbonate solution and water, and then dried. After concentrating the solution, 3.3 with a boiling point of 98°C to 102°C/55mmHg was distilled under reduced pressure.
-Ethyl-dimethyl-4-hexenoate 4,87 was obtained. Yield 56% Reference Example 1 FeC in dimethylformamide (DMF') 2.197
l3・6H20135.2Tf19 (0.5 mmol)
Dissolve 146.3η (2.0 mmol) of n-butylamine, and dissolve 1.56 ethyl 3,3-dimethyl-4-benzenate.
7 (10 mmol) and 4.26 y (30 mmol) of carbon tetrachloride were added, the tube was sealed, and the tube was heated at 100° C. for 15 hours.

The reaction solution was diluted with ether and washed successively with 1N hydrochloric acid, saturated aqueous sodium bicarbonate solution, and saturated brine. After drying and concentrating the ether solution, the boiling point was 116℃/0.1 by vacuum distillation.
3,3-dimethyl-4-chloro-5 with 8 mmHg
-2.797 ethyl trichloromethylvalerate was obtained. Yield: 90% Reference Example 2 1.017 (44 mm01e) of sodium metal was dissolved in 80 ml of absolute ethanol and cooled with ice water to form ethyl 3.3 dimethyl-4-chloro-5-trichloromethylvalerate6.
20y (20mm01e) in anhydrous ethanol solution (20mm01e)
m1) was added dropwise.

Claims (1)

[Claims] 1. Allyl alcohol derivative represented by the general formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ and the general formula RCH_
Reaction with orthocarboxylic acid ester represented by 2C(OR^1)_3 ▲There are mathematical formulas, chemical formulas, tables, etc.▼Production method of γ-unsaturated carboxylic acid ester represented by ▼ (in the formula R, R^2, R ^4 and R^5 are hydrogen or a lower alkyl group, R^1 is a lower alkyl group, and R^3 is a lower alkyl group or a phenyl group).