JPS5829775B2 - 2-(dihalovinyl)-cyclopropanecarbonate - Google Patents

Description

Detailed Description of the Invention The present invention is based on the general formula (I) (wherein R1, R2 and R4 represent the same or different alkyl groups, R3 represents a hydrogen atom or a lower alkyl group, and X and Y represent the same or different halogen groups). Indicates an atom.

), more specifically regarding the method for producing a 2-(dihalobinyl)-cyclopropanecarboxylic acid derivative represented by the general formula (In) (wherein R1 and R2 are as shown in the general formula (I), Xl, X2 and X3 represent the same or different halogen atoms.

) is a 1,1,1-trino, o-3-ene compound represented by the general formula (■) (wherein R3 and R4 are as shown in the general formula (I)).

) is reacted with a diazocarboxylic acid ester represented by the general formula (n) (wherein R1, R2, R3 and R4 are as shown in the general formula (I), Xl, X2 and X3 are the general formula % formula %) 2-(dihalovinyl)-cyclopropanecarboxylic acid derivative represented by the general formula (I), which is then treated with a base to undergo a dehydrohalogenation reaction. Relating to a manufacturing method.

In general formula (I), RI R2 and R4 are preferably alkyl groups having 1 to 20 carbon atoms.

Particularly preferably R1 and R2 are methyl groups, and R4 is a lower alkyl group such as methyl, ethyl or propyl.

R3 is preferably a hydrogen atom or a methyl group.

In the general formula (I[), Xi, X2 and X3 represent a halogen atom, preferably a chlorine atom or a bromine atom.

The compound represented by the general formula (I) obtained by the method of the present invention, especially the 2,2-dimethyl-3-(2゜2-dihalobinyl)cyclopropanecarboxylic acid derivative, is an important compound that has uses as an insecticide. .

This synthetic pyrethroid has superior durability and insecticidal efficacy, whereas natural pyrethroid insecticides have the disadvantage of rapid photodegradation (M).

Elliott et al., Nature, 244.456
(1973)).

Recently, as a method for synthesizing dihalogenovinyl-cyclopropanecarboxylic acid ester, a method was reported in JP-A-49-47531, in which chrysanthemum acid is ozonolyzed to obtain the corresponding aldehyde, which is then subjected to a Wittig reaction.

However, since this method uses expensive chrysanthemum acid as a starting material and requires complicated operations such as an ozone oxidation reaction and a Wittig reaction, it is considered difficult to adopt it as an industrial method.

Also, J. Farkas et al. Col 1ect, czec
h.

Chem, Corrmun, 24.2230 (
(1959) reported the diazoacetate method.

That is, 1°1.1-trichloro-4-methyl-3-
After acetylating penten-2-ol, it is reduced with zinc-acetic acid to obtain 1,1-dichloro-4,4-dimethylbutadiene, which is further reacted with diazoacetate to produce cyclopropanecarboxylic acid ester. That is.

However, this method also uses the raw material 1,1-dichloro-4,4
-It is an industrial method due to drawbacks such as the long reaction steps required for dimethylbutadiene synthesis, the complicated operation of zinc-acetic acid reduction, and the low addition reaction yield of diazoacetic ester of 37%. It can not be said.

The present inventors have diligently and in detail investigated a new and effective synthetic route for the above synthetic pyrethroids, and found that the general formula (II
The addition reaction of the 1,1,1-trihalo-3-ene compound represented by I) with the diazocarboxylic acid ester gives a cyclopropanecarboxylic acid derivative represented by the general formula (II) in high yield, and furthermore, the cyclopropane It has been discovered that a carboxylic acid derivative easily undergoes a dehydrohalogenation reaction with a base to produce a 2-(dihalobinyl)-cyclopropanecarboxylic acid derivative represented by the general formula (I),
The present invention has now been completed.

The 1,1,1-trihalo-3-ene compound represented by the general formula (1) used in the method of the present invention can be easily produced by the method shown below.

a) General formula (V) (wherein R1 and R2 are as shown in general formula (I), and R5 is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an acyl group.

) to a tertiary allyl alcohol or a derivative thereof under radical reaction conditions to obtain the general formula (IV) (wherein R1, R2 and R5 are as shown in the general formula (V)), Xl, X2 and X3 are of the same type (III)
As shown in

) is obtained, and the 1,11-trihalo-3-ene compound represented by general formula (III) is produced by subjecting it to dehydration, dealcoholization or decarboxylation reaction.

b) General formula (VI) (wherein R1 and R2 are as shown in general formula (I), and X4 represents a halogen atom.

) and tri- or tetrahalogenated methane under radical reaction conditions to form 1,1.
A 1-trihalo-3-ene compound is produced.

Conventionally, the radical addition reaction of haloform to primary allyl alcohol or its ether or ester has been described, for example, by Kharasch et al., J. Am.

Chem, Soc, 69.1105 (1974) and Lewis et al.
, 761457 (1954), a large number of teronia were produced, and Tarrant et al.
, Org, Chem, , 26.4646 (1961)
As stated in , the yield of 1:1 adduct is 20-30
It was a low %.

Also, tertiary compounds such as dimethylvinylcarbinol may also be used.
It is known that allylic alcohols of 100 to 100% can easily undergo a dehydration reaction under high heat.

However, when the tertiary allyl alcohol represented by the general formula (V) is reacted with haloform under radical reaction conditions, the expected dehydration reaction and formation of telomer hardly occur.

For example, dissolve 400 g of dimethylvinyl carbinol in 4.000 g of chloroform, and dissolve tert-perbenzoic acid.
After adding 30 g of butyl and reacting at 110°C for 30 hours, excess chloroform and unreacted dimethylvinyl carbinol were recovered under reduced pressure, and the residue was distilled to yield 1.1.1 with a yield of 82%. -Trichloro-4-methyl-4-pentanol is obtained.

By subjecting the thus obtained compound represented by general formula (IV) to dehydration reaction, dealcoholization reaction or decarboxylation reaction, 1 represented by general formula (nI),
1.1-) Rihalo-3-ene compound.

In carrying out this dehydration reaction, dealcoholization reaction or decarboxylation reaction, the compound represented by the general formula (IV) is mixed with sulfuric acid, phosphoric acid, boric acid, P-toluenesulfonic acid, phosphorus pentoxide, vanadium pentoxide, room temperature to 200 ℃ in the presence of a strong or weak acidic catalyst such as tungsten oxide.
'C, or silica gel,
80-250 in gas phase or liquid phase in the presence of silica alumina, pumice, diatomaceous earth, Fuller's earth, activated alumina, etc.
It may be heated to a temperature in the range of 'C.

In the latter case, it is also possible to use a combination of vanadium pentoxide supported on diatomaceous earth, for example, in order to accelerate the reaction rate.

The 1,1,1-t-IJ halo-3-ene compound obtained in this way may contain some 1,1,1-trihalo-4-ene compound depending on the reaction conditions, but this may be due to dehydration reaction or dealcoholization reaction. Alternatively, it can be easily isomerized to a 1.1.1-toIJ halo-3-ene compound under decarboxylation reaction conditions.

Furthermore, regarding the conventional radical addition reaction between primary allyl halide and tri- or tetrahalogenated methane, for example, Khar a sch et al.
.

As reported in Chem., 14.537 (1949), in the reaction of allyl bromide and bromotrichloromethane, a large amount of 1.1.1.5.5.5-hexachloro-3-brompenkune is produced as a by-product. In addition, 1,2,3- which has two bromine radicals added to allyl bromide
Tribromopropane is produced as a by-product.

To date, there have been few reports on the radical addition reaction of tri- or tetrahalogenated methane to tertiary allyl halides.

In other words, it is known that tertiary allyl halides are easily rearranged to primary allyl halides by heat, or undergo dehydrohalogenation to produce dienes, so the desired addition reaction can be carried out with high selectivity. It was considered difficult to do so.

However, surprisingly, the third compound represented by the general formula (-Vl)
When aral halides of the general formula (II) are reacted with tri- or tetrahalogenated methane under radical reaction conditions,
A 1,1,1-toIJ halo-3-ene compound represented by I) was obtained in good yield.

Here, the radical reaction conditions used in a) or b'yD method include the presence of a radical reaction initiator,
Or it can be achieved by irradiating light.

As a radical reaction initiator, benzoyl peroxide (BPO
), azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, peracetic acid, perbenzoic acid t
ert-butyl, tert-butyl perphthalate, te
rt-butylhydrobar oxide, cumene hydroperoxide, etc. can be used.

The radical reaction initiator may be used in a contact amount.

The reaction temperature is preferably room temperature to 100'C when light is used as the radical reaction initiation method, and 70 to 180C when a radical reaction initiator is used.

1 represented by the general formula (1) obtained in this way,
When a 1.1-toIJ halo-3-ene compound is reacted with a diazocarboxylic acid ester represented by the general formula (■), a cyclopropanecarboxylic acid derivative represented by the general formula (If) can be produced in high yield.

Although this reaction proceeds without a catalyst, 1,1,1-tI
J Insertion reaction of carboethoxycarbene into halo-3-ene compound or dimer of carboethoxycarbene itself,
Trimers diethyl maleate, diethyl fumarate,
Since a competitive reaction occurs with the production reaction of ethyl tricarboxylate and the like, it is usually preferable to use a catalyst and carry out the reaction under miscible conditions.

As a catalyst, copper or a catalyst containing copper as a component (cupric sulfate, cuprous chloride, cupric chloride, cuprous cyanide, copper acetylacetonate, tri-n-butylphosphine-cuprous iodide complex) , cuprous thiocyanide, etc.), π-allyl palladium chloride, nilakerosene, etc. can be used.

Also, Nozaki et al. reported Tetrahedron, 24.3655
(1968), it is also possible to use an optically active copper complex to produce an optically active cyclopropanecarboxylic acid derivative represented by general formula (II).

The reaction temperature may be room temperature to 700C depending on the catalyst used, but is preferably 7000 to 150C, particularly preferably 80 to 125C.

In carrying out the reaction, the ratio of the 1,1.1-trihalo-3-ene compound to the diazocarboxylic acid ester may be 1:1, but in order to obtain the cyclopropanecarboxylic acid derivative represented by the general formula (n) with high selectivity. , usually 1,1.1
- It is preferable to use a large excess of the IJ halo-3-ene compound.

When carrying out the reaction, either a patch method or a continuous reaction method may be employed.

In the case of a batch process, preferably 1,1.1-M l-3
The -ene compound and the catalyst are placed in a reactor in advance and heated, and then the diazocarboxylic acid ester (this diazocarboxylic acid ester may be 1,1.1-t
-Can also be diluted with IJ halo-3-ene compounds)
was added dropwise to cause a reaction, and after the reaction, the catalyst was separated from the reaction solution, the excess 1.1.1-t'J halo-3-ene compound was recovered under reduced pressure, and the residue was prepared by general formula (I[) A cyclopropanecarboxylic acid derivative represented by is obtained.

Note that the recovered catalyst can be reused.

When a continuous reaction method is adopted, a reaction tower packed with a catalyst is usually used, and the diazocarboxylic acid ester L L 1- ), + is placed at an appropriate height in the reaction tower.
) Feed the halo-3-ene compound solution.

By providing a separation column for low boiling point components and 1.1.1-toIJ halo-3-ene compounds above this feedro, the 1,1.1-
Since a large amount of the H-halo-3-ene compound is present, the reaction proceeds in a considerably diluted state of the supplied diazocarboxylic acid ester.

This is very important not only for improving the selectivity of the reaction but also for the safety in handling the diazocarboxylic acid ester.

By providing the section 1 below the feedlot also as a rectification column, only the cyclopropanecarboxylic acid derivative represented by the general formula (II) can be continuously taken out from the bottom section of the column.

The cyclopropanecarboxylic acid derivative represented by the general formula (If) obtained in this way can be easily converted into 2-(dihalobinyl)-cyclopropanecarboxylic acid represented by the general formula (I) by treating it with a base. It can be a derivative.

Bases used include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide: sodium methoxide, sodium ethoxide, potassium methoxide, sodium tert-butoxide, potassium tert-
Metal alkoxides such as butoxide, sodium tert-aluminum oxide; hydrogen [alkali metal hydrides such as sodium hydride and potassium hydride; alkali metal amides such as sodium amide and 1,5-diazabicyclo(3
,4,0) Nonene-5 (referred to as “DBN”), 1,5-
diazabicyclo(5,4,0)undecene-5(1'-
Examples include organic amines such as DBU, J), 2-dimethylamino-1-pyrroline; organic lithium compounds such as n-butyllithium, 5ec-butyllithium, and diisopropylaminolithium; however, the reaction efficiency It is preferable to use alkali metal hydrides and alkali metal hydroxides because of their high .

The amount of the base used is 1 molar equivalent or more, preferably 1 to 2 molar equivalents, based on the raw material.

The reaction is preferably carried out in a solvent, and examples of the solvent include alcoholic solvents such as methanol and ethanol, N,N-dimethylformamide (DMF), dimethyl sulfoxide (IMSO hemorrhoids, aprotic polar solvents, or carbonized solvents such as benzene and toluene). Examples include hydrogens and the like.

When using organic amines, they may be used in excess to also serve as a solvent.

When the reaction is carried out in an alcohol solvent, it is usually preferable to use the same alcohol as R4 since transesterification may occur between the alcohol used and the R4 group.

The reaction ranges from room temperature to 1500C, preferably 50C.
It is easier to carry out the operation at the reflux temperature of the solvent.

2- represented by the general formula (I) thus obtained
(dihalobinyl)-cyclopropanecarboxylic acid derivative,
Especially 2,2-dimethyl-3-(2,2-dihalobinyl)
Cyclopropane carboxylic acid esters are important compounds that can be used as insecticides.

Hereinafter, the present invention will be explained in more detail with reference to Reference Examples and Examples.

Reference Example 1 Dimethylvinyl carbinol 401 was dissolved in 4,000 g of chloroform, tert-butyl perbenzoate was added to the solution, and the reaction was carried out at 110°C for 30 hours. Unreacted dimethylvinyl carbinol was recovered under reduced pressure to obtain 835 g of a reddish-yellow viscous liquid as a residue.

As a result of gas chromatography analysis, this product has a purity of 9.
0.4% 1.1.1-trichloro-4-methyl-4-
It contained 8.7% of 1,1.3-t-lichloro-4-methyl-4-pentanol as an impurity.

By vacuum distilling the above residue, bp60-61.5
1.1. of high purity as a fraction at °C (0.3 mmHg).
1-t'J chloro-4-methyl-4-pentanol 7
32g was obtained.

When this substance was left to stand, it turned into white crystals.

The product was confirmed by the following method. Infrared absorption spectrum 3340.1380, 1368, 1280, 1220° 1150.1073, 1035, 942, 910° 79
5 745 695cfrL-1 Mass spectrum 189.191,193,195 (3 ClX) CM)
+-CH3 nuclear magnetic resonance spectrum δ″n co14 ppm 1, 22 s, 6H@CH3
ca 1.70-1.95 m, 2H, -CH
2-ca 2.64-2.92 m, 2H,
-CH2- Then, 7.3 g of p-t/reninsulfonic acid was added to 732 g of 1,1.1-)lichloro-4-methyl-4-pentanol and heated at 155 to 160'C for 1.5 hours to produce a by-product. The reaction was carried out while expelling water from the system.

The reaction solution was directly distilled off under reduced pressure of 200 mmHg, and the distillate was dried over sulfur and then subjected to precision distillation. 62 g of 1.1-trichloro-4-methyl-4-pentene was obtained, bp 74-77°C (2 ozmHg
) as a fraction of 1,1.1-trichloro-4-methyl-
536 3-pentene! 94.

The structure of the product was confirmed by the following method.

Nuclear magnetic resonance spectrum δ 1°001・99m 1.66.1.75 each s, 6H, CH
3-3,29d,2H,-CH2 5,35t,IH,-CH= Reference Example 2 Add p- ) Luensulfone eo, 3f! was added, and the isomerization reaction was carried out at 130 to 135°C with stirring for 8 hours.

The reaction solution was directly distilled off under reduced pressure.

Gas chromatography analysis of the distillate shows 1.1.1
-t-rift-4-methyl-4-pentene pair 1,1.
The ratio of 1-trichloro-4-methyl-3-pentene is 1
The ratio was 3:87, and almost no other by-products were observed.

The distillate was precisely distilled as it was to obtain 1,1.1-)lichloro-4-methyl-3-pentene 50. 'I got H1.

Reference Example 3 A reaction tube with an inner diameter of 3 crrL and a length of 30 crfL is filled with 150 ml of silica alumina catalyst and heated to 140°C.

To this, 606 g of 1,1.1-)lichloro-4-methyl-4-pentanol obtained by the method of Reference Example 1 was added to 202 g.
Feed at a rate of /hr.

After the distillate leaving the reactor is trapped through a cooling pipe,
Ether is added to this, and the ether layer is washed with water and dried.

When the ether was distilled off under reduced pressure and the residue was analyzed by gas chromatography, it was found that 1.1.1-trichloro-4-methyl-
The ratio of 4-pentene to 1,1.1-1-lichloro-4-methyl-3-pentene is 25 to 75, and the raw material 1,1
．． The conversion rate of 1-1-lichloro-4-methyl-4-pentanol was 97.1%.

By precision distilling the residue, 113 g of 1.1.1-trichloro-4-methyl-4-pentene and 1,1.1
325 g of -trichloro-4-methyl-3-pentene were obtained.

Example 1 3.5 g of anhydrous copper sulfate in the third flask of 5001111
and 200 g of 1,1.1-trichloro-4-methyl-3-pentene and heated to 1000C.
A solution dissolved in 150 g of 4-methyl-3-pentene was
Drip slowly over time.

After the dropwise addition was completed, the reaction humidity was raised to 120'C and the reaction was carried out for 30 minutes.

After cooling, the reaction solution was filtered to separate the catalyst, and then the excess 1.1.1-tIJrimachi-4-methyl-3-pentene was recovered by vacuum distillation, and the residue was vacuum distilled to give bp87. 79.69 ethyl 2,2-dimethyl-3-(2,2,2-)lichloroethyl)cyclopropanecarboxylate was obtained as a fraction of ~92°G (0.25°Hg).

As a result of gas chromatography analysis, the purity of this ethyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate was 86.3%.

Next, this product was purified using a precision distillation column with about 40 theoretical plates to obtain a mixture of 2,2-dimethyl-3 with a purity of 98.9% and a cis:trans stereoisomer ratio of 47:53. 63.7 g of ethyl -(2,2,2-)lichloroethyl)cyclopropanecarboxylate was obtained.

The structure of the product was confirmed by the following method.

The 2,2-dimethyl-3-(2,
27.2 g of ethyl 2,2-trichloroethyl)cyclopropanecarboxylate (cis to trans stereoisomer ratio -4
7 to 53) of absolute ethanol 200% vertically to metal ST-IJ
It was added dropwise at room temperature to a solution containing 4.6 g of aluminum dissolved therein, and after the dropwise addition was completed, the reaction humidity was raised to 40°C for 2 hours, and then further heated at 50°C.
The mixture was heated and reacted for 2 hours.

After the reaction, the reaction mixture is neutralized with a saturated ethanol-hydrochloric acid solution under water cooling, and after ethanol is distilled off under reduced pressure, the residue is dissolved in ether and washed with water.

After drying with boronic acid, the ether was distilled off and the residue was distilled under vacuum to obtain a fraction with a bp of 70 to 72°G (0.35 mmHg). 19.3g of ethyl carboxylate was obtained.

As a result of gas chromatography analysis, the purity of this ethyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate was 97.5%, and the isomer ratio of cis to trans was 97.5%. It turned out to be 45-55.

The structure of ethyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate was determined by the following method.

Example 2.

As in Example 1, add 3.0 g of copper powder to the third flask of No. 11.
and 1,1.11-trichloro-4-methyl-3-pentene 30 (Bli' was added and heated to 90°C, and 50 g of ethyl diazoacetate was added to 1,1.1-trichloro-4-methyl- A solution of 450 g of 3-pentene was slowly added dropwise over 8 hours.

After the dropwise addition was completed, the reaction temperature was raised to 120°C and the reaction was continued for 30 minutes.

After cooling, the reaction solution was filtered to separate the catalyst, and then the excess 1.1.1-tIJrimachi-4-methyl-3-pentene was recovered by vacuum distillation, and the residue was vacuum distilled to obtain 2. , 2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate ethyl 89.3.9 was obtained.

As a result of gas chromatography analysis of this product, the purity was 94.2%, and the cis to trans stereoisomer ratio was 49.
It was 51 against.

Next 1.1. 27.2 g of l-trichloro-4-methyl-3-pentene was dissolved in 300 g of dry benzene, 19.2.9 g of sodium tert-butoxide was added thereto, and the reaction was carried out at 50°C for 4 hours. Pour into ice water and perform ether extraction.

After washing with water, drying with sulfur salt, and concentrating, the residue was vacuum distilled. 2.2. -dimethyl-3-(2,2-diclobinyl)
20.4 g of ethyl cyclopropanecarboxylate was obtained.

Examples 3-5 Next, the continuous manufacturing method of the present invention will be explained.

The equipment consists of a reaction tower filled with a catalyst, a recovery device for low-boiling products at the top, and a reboiler connected at the bottom of the tower.
A device is used in which a raw material supply port is provided at an appropriate height of the reaction tower, and the reaction tower is filled with a copper filler.

First, only 1,1.1-toIJchloro-4-methyl-3-pentene is supplied for distillation, and at the point when reflux begins, 1,1.1-chloro-4-methyl-3-pentene containing 10% by weight of ethyl diazoacetate is added from the raw material supply port of the reaction column. 1.1- Trichlor-4-
Feed the methyl-3-pentene solution.

The produced ethyl 2,2-dimethyl-3-(2,2,2-t-lichloroethyl)cyclopropanecarboxylate was continuously taken out from the boiler.

The reaction conditions and yield at that time are as listed in Table 1.

Examples 6 to 8 As in Example 1, each type of 1,
0.3 mol of 1.1-trihalo-3-ene compound
.

Then, 15 mmol of the catalyst was added and heated, and a 5 mol solution of 1.1.1-trihalo-3-ene compound Q, containing 50 mmol of diazocarboxylic acid ester, was slowly added dropwise thereto.

After dropping, the reaction temperature was raised to 120°C and heated for 30 minutes to complete the reaction.

After the reaction solution was cooled, the catalyst was separated, and the filtrate was distilled under reduced pressure to recover excess 1.1.1-trihalo-3-ene compound, and the residue was vacuum distilled to obtain cyclopropanecarboxylic acid ester. I took it out.

The results *trees are shown in Table 2.

Example 9 In the same manner as in Example 1, LL, 1. -Trichloro-4-methyl-3-pentene Q, 3 mol and 30 pieces of cuprous thiocyanide were placed in a third 300ml flask, and 50mm of ethyl diazopropionate was added.
A solution of 0.6 mol of 1.1.1-trichloro-4-methyl-3-pentene was added dropwise at 85°C.

After the dropwise addition was completed, the reaction was carried out at 120°C for 30 minutes, and after cooling, it was poured into water and extracted with ether. After drying this extract with glass salt, the ether was distilled off under reduced pressure, and the residue was distilled under reduced pressure. excess of 1.1.1-1-IJ chloro-4-methyl-
3-Recover pentene.

The remaining ethyl 1,2,2-trimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate was prepared in a system in which 100 mmol of sodium hydride was dispersed in 100 ml of anhydrous dimethoxyethane without purification. Drip into.

After completion of the reaction, the reaction is carried out at 50°C for 6 hours and then cooled.

After neutralization with saturated ethanolic hydrochloric acid solution, it is poured into water and extracted with ether, and this extract is washed with brine and dried.

After distilling off the solvent, bp71-75°CCO,
1,2,2-1-limethyl- with 08imHg)
Ethyl 3-(2,2-dichlorovinyl)cyclopropanecarboxylate was obtained in a yield of 58%.

The product was found to be 2,2-dimethino L/-3- obtained by the method of Example 10 and Example 8 in the nuclear magnetic resonance spectrum.
50 mmol of ethyl (2,2,2-t-ribromoethyl)cyclopropanecarboxylate was added dropwise to a system in which 100 mmol of sodium amide was dispersed in 1001 nl of anhydrous tetrahydrofuran, and the mixture was then heated and reacted at 50°C for 6 hours. .

After neutralizing the reaction solution with saturated ethanolic hydrochloric acid solution, tetrahydrofuran was distilled off under reduced pressure, poured into water, and extracted with ether.

This extract was washed with saturated saline, dried over salt water, and the ether was distilled off under reduced pressure.

Vacuum distillation of the residue yields bp 92-94°C (0.51r
2,2-dimethyl-3-(2,
Ethyl 2-dibromvinyl)cyclopropanecarboxylate was obtained in a yield of 78%.

This one has an infrared absorption spectrum of 16001-
1 (>C=C(), 1730crrL-1(co), nuclear magnetic resonance spectrum (100MHz) niote δinC"14: 1.19 (s), 1.23
(t.

J = 7 Hz), 1.26(s)9H; 1.5
3 (d, J = 5Hz) IH; 2.08 (dd
, J=5.8Hz) IH; 4.03 (q, J-
=7Hz)2H; 6.04(d, J=8Hz)
It showed LH.

Example 11 55 mmol of DBU was dissolved in 100 ml of anhydrous benzene, and 50 rrmo 1 of ethyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate obtained by the method of Example 1 was dissolved in 100 ml of anhydrous benzene. A solution of 20rrLl of benzene was added dropwise at room temperature, and after completion, the solution was heated to 40°C.
The mixture was heated and reacted for 6 hours.

After the reaction solution is cooled, it is washed with saturated saline and dried over sulfur salt.

Benzene was distilled off under reduced pressure and the residue was distilled under reduced pressure to obtain ethyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate in a yield of 74%.

Claims (1)

[Claims] 1 1, 1 represented by the general formula (I[l) (wherein R1 and R2 represent the same or different alkyl groups, and Xl, X2 and X3 represent the same or different halogen atoms) ', 1-trihalo-3-ene compound is represented by the general formula (■) (wherein R3 represents a hydrogen atom or a lower alkyl group,
4 represents an alkyl group. ) is reacted with a diazocarboxylic acid ester represented by the general formula (1) (wherein R1, R2, Xl, X2 and X3 are the general formula (I
II), and R3 and R4 are as shown in general formula (■). The general formula (I) is characterized in that it is a cyclopropanecarboxylic acid derivative represented by
2 is as shown in the general formula (■), and R3 and R
4 is as shown in the general formula (■), and X and Y represent either Xi, X2 or X3 shown in the general formula (III). ) A method for producing a 2-(dihalobinyl)-cyclopropanecarboxylic acid derivative represented by: