JPS5817451B2 - Production method of γ↓-chloro↓-δ↓-unsaturated carboxylic acid ester - Google Patents

Description

Detailed Description of the Invention The present invention is based on the general formula (wherein R1 is an alcohol residue, R2, R3, R4
and R5 is hydrogen or a lower alkyl group.

) The present invention relates to a method for producing a γ-chloro-δ-unsaturated carboxylic acid ester represented by:

The γ-rho δ-unsaturated carboxylic acid ester represented by the general formula (I) is an intermediate for the synthesis of the unit constituting the acid moiety of synthetic pyrethroid compounds, which are attracting attention for their usefulness as insecticides. be.

That is, by ring-closing the compound of the general formula (I) in the presence of a base, a cyclopropanecarboxylic acid ester having a dichlorovinyl group can be derived (see the reference side below).

Conventionally, DDT and BHC have been used as insecticides, but due to their residual toxicity, there is currently 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.

A disadvantage in the use of natural pyrethroid insecticides is that they biodegrade quickly.

As a result of testing many compounds to solve this drawback, it became clear that cyclopropanecarboxylic acid ester having a dihalobinyl group has low toxicity and excellent durability (M-Elliott, et al.).

Nature, 246, 169 (1973)).

Conventionally, methods for synthesizing this type of compound include (1) a method using natural chrysanthemum acid as a starting material [see JP-A-49-47531, G-Brown, et al.

J-Agr, FoodChem, , 21.76
7 (1973)) (2) Method for adding diazoacetate to dihalobutadiene (J-Farkas, eta
ll, Co11. Czeck, Chem, Com
m0, 24°2230 (1959)) has been proposed.

However, all of these conventional methods have drawbacks such as expensive starting compounds, long synthetic routes, and the need for expensive auxiliaries.

The present inventors have made intensive studies to solve these drawbacks of the conventional methods, and have found that the compound of the general formula (T) can be industrially advantageously derived into a cyclopropanecarboxylic acid ester having a dichlorohinyl group. This led to the completion of a simple manufacturing method.

The method of the present invention uses a raw material having the general formula [where R1 is an alcohol residue and R2, R3R4 and R5 are hydrogen or a lower alkyl group].

A δ-trichloromethyl-γ-unsaturated carboxylic acid ester represented by the following formula is used.

This compound can be easily formed, for example, by adding a tetra-logenated carbon to a γ-unsaturated carboxylic acid ester formed from an allyl alcohol derivative and an orthocarboxylic acid ester, and then treating it with a specific amount of base (
(See reference side below).

δ-Trichloromethyl- represented by the general formula (Company)
Examples of the γ-unsaturated carboxylic acid ester include methyl 3,3-dimethyl-5-trichloromethyl-4-pentenoate;
Ethyl 3,3-dimethyl-5-trichloromethyl-4-pentenoate, 2.3.3-toIJmethyl-5-to'J
Ethyl chloromethyl-4-pentenoate, 3,3.5-
Ethyl 4-trimethyl-5-trichloromethyl-4-pentenoate, 3-methyl-5-)! J Chlormethyl-4
-Ethyl pentenoate, 5-trichloromethyl-4-ethyl pentenoate, 3,3-dimethyl-5-trichloromethyl-4, ----hentenoic acid tumetaphenoxybenzyl ester, 3,3-dimethyl-5- trichloromethyl-
Examples include 4-pentenoic acid (7) 5-hensyl-3-furylmethyl ester, ethyl 2-ethyl-3,3-dimethyl-5-trichloromethyl-4-pentenoate, and the like.

An essential requirement of the present invention is that the δ-trichloromethyl-γ-unsaturated carboxylic acid ester represented by the above general formula is isomerized under heating or in the presence of an acidic catalyst.

This heat treatment is performed at 508C to 200C.

If the temperature is below 50°C, the reaction will be extremely slow, and if it is above 200°C, by-products will be formed, which is not preferable.

The preferred heating temperature is 100 to 170°C.

Moreover, this isomerization reaction can also be achieved by the presence of an acidic catalyst.

As the acidic catalyst, lower fatty acids such as acetic acid, propionic acid, butyric acid, and isobutyric acid, phenols such as phenol and hydroquinone, and Lewis acids such as aluminum chloride, zinc chloride, and boron trifluoride can be suitably used.

The amount of these acidic catalysts to be used is generally from 0.05 to 10 mol based on the raw material compound.

In the case of using an acidic catalyst, the reaction can be accelerated by combined use of heat treatment, and this is also an embodiment of the present invention.

The present invention can be carried out without using a solvent, but if desired, a solvent that does not directly participate in the reaction may be used, such as high-boiling ethers such as benzene, toluene, xylene, tetralin, high-boiling petroleum ether, dimethoxyethane, and diglyme. There is no problem in one aspect.

The present invention will be explained in more detail below with reference to Reference Examples and Examples.

Example 1 Ethyl 3,3-5-trichloromethyl-4-pentenoate 547■ (2 IJ mol) Tetralin 2
ml and heated at 150°C for 24 hours under an argon atmosphere.

Then, by distillation under reduced pressure, the boiling point is 88-90°C/0.2
3,3-dimethyl-4,6,6-4 with mmHg
356 m9 of ethyl chlor-5-hexenoate was obtained.

Yield: 65 Infrared absorption of product (KBrcm), 1
735°1613 nuclear magnetic resonance absorption (CC14, δ)5.
96 (d IH), 4.85 (d IHL4.06
((12H), 2.4x(d IH).

2.23 (d IH), 1.23 (t 3H).

1, INs 6H)・Example 2 Ethyl 3.3-dimethyl-5-trichloromethyl-4-henthenate 547a? (2 mmol) Woxylene 2 ml
After adding 30 μm of isobutyric acid, the mixture was heated under reflux under an argon atmosphere for 6 hours.

After distilling off the solvent, reduce the boiling point to 85-86°C by distillation under reduced pressure.
3,3-dimethyl-4,6, with 0.1 mmHg
Ethyl 6-dolychloro-5-hexenoate 416 was obtained.

The spectrum of the product obtained in 76% yield matched that of the product of Example 1.

Example 3 Ethyl 3.3-dimethyl-5-trichloromethyl-4-pentenoate 547 ~ was heated at 150°C under 8Mt of Albod at 10
heated for an hour.

Then, by vacuum distillation, the boiling point was 84-85°C/0.
Ethyl 3,3-dimethyl-4,6,6-4lichloro-5-hexenoate 24 as an oil with 0.09 mmHg
I got 6~.

Yield: 45.

This product has an IR1 NMR spectrum. The product was compared with the product obtained in Example 1 by gas chromatography and gas chromatography.

Example 4 3,3-dimethyl-4,6,6-dolychloro-5 was obtained by performing the same operation as in Example 2 except that 2 ml of diglyme was used as the solvent and heated to 150°C.
-Ethyl hexenoate 383- was obtained.

Yield 70%. The product was comparatively identified by spectroscopy and gas chromatography.

Example 5 30 m9 of aluminum chloride was added to 274~ of ethyl chloromethyl-4-pentenoate (3,3-thume root 5-t), and the mixture was stirred at room temperature for 24 hours.

When the product was examined by gas chromatography, it was confirmed that ethyl 3,3-dimethyl-4,6,6-dolychloro-5-hexenoate was produced at a yield of 30%.

Example 6 2.3.34 Ethyl-5-trichloromethyl-4-pentenoate 288 ~ After dissolving in 1 ml of xylene, adding phenol 30rn9, under argon atmosphere,
The mixture was heated under reflux for 10 hours.

After cooling, the solvent was distilled off, and the boiling point was reduced to 9 by distillation under reduced pressure.
Ethyl 2,3.3-4-limethyl-4,6,6-4-lichloro-5-hexenoate 1961n9 was obtained as an oil with a temperature of 1-93°C/0.12 mmHg.

Yield: 68.

Nuclear magnetic resonance absorption of product (CC14, δ) 5.95,5
．． 94 (d IH), 4.77.4.62 (d I
H), 4.03.4.02 (q 2H).

2.80-2.35 (m IH), 1.22 (t3H
), 1.35-o,9o (m 9H) Example 7 m-phenoxybenzyl 3,3-dimethyl-5-trichloromethyl-4-pentenoate 427,5- synthesized by the same method as Reference Example 1 was dissolved in 2 ml of xylene, and 30~ of isobutyric acid was added.

The solution was heated to reflux under an argon atmosphere for 6 hours.

After distilling off the solvent, silica gel column chromatography was performed to obtain 3,3-dimethyl-4,6,6-dolychloro-5.
291 ml of m-phenoxybenzyl-hexenoate was obtained.

Yield: 68. Nuclear magnetic resonance absorption of raw material (CC14, δ) 7.4-6.7 (m 9HL 6.23 (d IH
).

5.95 (d IH), 4.93 (s 2H
).

Nuclear magnetic resonance absorption (CC14, δ) of 2.33 (s 2H), 1.18 (s 6H) products 7.5-6. s(
m 9H), 5.95 (d in).

4.95 (s 2H), 4.85 (d IH
).

2.40 (d IH), 2.22 (d IH).

1.10 (s 6H) Reference Example 1 2ml of an anhydrous tetrahydrofuran solution of ethyl 3.3-dimethyl-4-bromo-5-4lichloromethylvalerate 709~(2mm01) was heated to 163mF? (2,4 mmo
A solution of 20 ml of anhydrous tetrahydrofuran in which sodium ethoxide (1) was suspended was added to a water-cooled bottom, and at room temperature,
Stirring was continued overnight.

Then, it was poured into ice water, extracted with ether, and dried.

After distilling off the solvent, it is distilled under reduced pressure to a boiling point of 83-85°C10
, 1 mm Hg was obtained from 448~.

Yield: 82 (Purity: 85 or higher) Nuclear magnetic resonance absorption of one pure product (CC14, δ) 6.1
3 (q, 2H), 4°07 (q, 2H), 2°
29 (s, 2H), 1.50-1.00 (m, 9H).

Reference Example 2 737 ml of ethyl 2.3.3-trimethyl-4-bromo-5-todichloromethylvalerate (2 mmole) was dissolved in 20 ml of anhydrous tetrahydrofuran and cooled on ice.

To this solution, 163-(2.4 mmol) of sodium ethoxide was added in portions.

After 5 hours, the mixture was poured into ice-cooled diluted hydrochloric acid, extracted with ether, washed with water, aqueous sodium bicarbonate, and saturated brine, and then dried.

After distilling off the solvent, the boiling point was 92-95℃10.2 by distillation under reduced pressure.
430 mg of ethyl 2,3.3-)dimethyl-5-trichloromethyl-4-pentenoate with mm Hg were obtained.

Yield: 75. Nuclear magnetic resonance absorption of product (CC14, δ)
6.15 (q 2H), 4.07 (q 2H).

2.70-2.10 (m IH), 1.24 (t3H
), 1.30 to 0.90 (m 9H) Reference Example 3 3.3-Dimethyl-4,6,6-)lichloro-5-hexenoate ethyl 5477Q (2 mmol) was dissolved in 2 ml of total anhydrous ethyl alcohol.

Add this solution to 57 μm (2.5 mmol) of metallic sodium
Dropped into 10 ml of absolute ethyl alcohol dissolved in L, 5
Stirred at room temperature for an hour.

Thereafter, the reaction solution was cooled with ice water, and anhydrous ethyl alcohol solution of hydrogen chloride was added dropwise to neutralize it.

After concentrating to 1/10 volume, ether was added, poured into ice water, and the ether layer was washed with an aqueous sodium bicarbonate solution and saturated brine, and dried.

After distilling off the solvent, reduce the boiling point to 75-76° by distillation under reduced pressure.
C10,2-42,2-dichlorovinyl)-3,3-dimethylcyclopropanecarboxylate with 25 Hg 436rn? I got it.

Yield: 92.

Nuclear magnetic resonance absorption (δ
, CC14): 5.56 (a IH).

4.05 (bq 2H), 2.12 (dd IH)
1.47 (a IH), 1.50-1.1o (m9H
)・In addition, 6.22 (d), 2.35 to 2.10
Absorption derived from the cis isomer was observed in (m).

The ratio of cis to trans is approximately 2:8 from nuclear magnetic resonance absorption.
Met.

Reference Example 4 Ethyl 3.3-dimethyl-4,6,6-)dichloro-5-hexenoate 547 ~ (2 mmol) was dissolved in 2 ml of completely dry tetrahydrofuran.

This solution was added dropwise to 10 ml of dry tetrahydrofuran to which 288 μm (3 mmol) of sodium t-butoxide had been added, and the mixture was stirred at room temperature for 2 hours.

Thereafter, the reaction solution was poured into ice water, extracted with ether, and dried.

After distilling off the solvent, the boiling point is 78-79 by distillation under reduced pressure.
Ethyl 2-(2,2-dichlorovinyl)-3,3-dimethylcyclopropanecarboxylate 4277721 with °C/0.35 mmHg; JtJit.

Yield: 90.

The spectrum of the product almost matched that of the compound obtained in Reference Example 3.

The cis to trans ratio was approximately 1:9.

Reference example 5 2.3.3-)dimethyl-4,6,6-4lichloro-5
- A solution of 575 μm (2 mmol) of ethyl hexenoate in 5 ml of anhydrous dimethoxyethane was added with 120 μm (2 mmol) of sodium hydride (
50%, 2.5 mmol) was added dropwise to 10 ml of anhydrous dimethoxyethane dispersed therein.

Thereafter, heating under reflux was continued for 5 hours, and the mixture was cooled. After cooling with ice and neutralizing with dilute hydrochloric acid, extracting with ether and removing carbon hydrogen)
It was washed with an aqueous solution of Jum and a saturated saline solution and dried.

After distilling off the solvent, reduce the boiling point to 75-78°C by distillation under reduced pressure.
1-methyl-2-(2,2
360 μm of ethyl (-dichlorovinyl)-3,3-dimethylcyclo-propanecarboxylate was obtained.

Yield: 72 cm. Nuclear magnetic resonance absorption of product (CC14, δ)
:6.26.5.57 (d IFI), 4.10
(q2H), 2.28, 1.52 (d IB), 1.
39~o, c+o (m 12H).

Claims (1)

[Scope of Claims] 1 A compound represented by the general formula, characterized by isomerizing a δ-totrylolmethyl-γ-unsaturated carboxylic acid ester represented by the general formula under heating or in the presence of an acidic catalyst. [In the formula, R1 is an alcohol residue, R2, R3, R4 and R
5 is hydrogen or a lower alkyl group. ].