JPH0617334B2 - Method for producing racemic-trans primary chrysanthemic acid - Google Patents

Description

The present invention relates to a method for producing racemic-trans primary chrysanthemic acids, and more particularly to the general formula (I) (In the formula, R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,
Represents a cycloalkyl group or an aralkyl group. ) In the presence of an azo compound or a peroxide, a racemic-cis or mixed racemic-cis / trans mixed primary chrysanthemic acid represented by the following formula: carboxylic acid bromides, silicon bromides, S-bromo compounds, N-bromo compounds The present invention relates to a method for producing a corresponding racemic-trans primary chrysanthemic acid by reacting at least one bromine compound selected from the group.

Primary chrysanthemic acid constitutes the acid component of low-toxic, fast-acting insecticidal ester called so-called pyrethroid such as pyrethrin, allethrin and phthalthrin, and is useful as a raw material for these pyrethroid insecticides.

It is known that primary chrysanthemic acid has cis and trans geometrical isomers, and the insecticidal effect of trans-form ester is stronger than that of cis-form ester. Therefore, trans-transformation of the cis form into a trans form is far more advantageous from the viewpoint of insecticidal efficacy than using a cis form or an ester containing a large amount of cis form.

Conventionally, the primary chrysanthemic acid ester of the primary chrysanthemic acid is represented by the following formula by the method of reacting 2,5-dimethyl-hexa-2,4-diene and diazoacetic acid ester. Is widely industrially produced by hydrolyzing the ester.

However, since the primary chrysanthemic acid obtained by the method is obtained as a mixture of the target trans-form and cis-form, the technique of converting cis or cis / trans mixed primary chrysanthemic acid into the trans-form has important significance. .

Conventionally, as a method for converting a cis-primary chrysanthemate to a trans-primate chrysanthemate, a cis-primary chrysanthemate is added to a lower alkyl primary alcoholate of an alkali metal at about 150 ° C in the presence of a lower alcohol. Method of acting at 200 ° C. (Japanese Patent Publication No. 40-6457) or treatment with a special basic catalyst (Japanese Patent Publication No. 53-18)
No. 495, Japanese Patent Publication No. 53-13496, etc.), and a method of reacting a cis primary chrysanthemic acid ester with boron trifluoride etherate, iron chloride, aluminum chloride, etc. (JP-A No. 57-176930). Are known.

Further, as a method for directly converting cis primary chrysanthemic acid into trans primary chrysanthemic acid, a method of heating cis primary chrysanthemic acid at a temperature of 180 ° C. or higher (JP-A-49-126650),
Alternatively, it is said that cis-primed chrysanthemic acid can be converted into trans by reacting it with a nitrile complex catalyst of palladium dichloride (Tetrahedron Letters. 22,385 (1981)), but the former requires heating at high temperature and yield However, the latter has the drawback of requiring a relatively large amount of expensive reagents.

The inventors of the present invention have conducted extensive studies to find out a more excellent method for producing trans primary chrysanthemic acids, and as a result, carboxylic acid bromides, silicon bromides, S-bromo compounds, N
-A bromine compound such as a bromine compound was found to unexpectedly smoothly and efficiently proceed trans conversion of cis primary chrysanthemic acid by sharing it with an azo compound or a peroxide, and further The present invention was reached after further study.

That is, the present invention is represented by the general formula (I) (In the formula, R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,
Represents a cycloalkyl group or an aralkyl group. ) In the presence of an azo compound or a peroxide, a carboxylic acid bromide, a brominated silicon, an S-bromo compound,
The present invention provides an industrially excellent method for producing trans-primary chrysanthemic acid, which comprises transacting at least one bromine compound selected from N-bromo compounds.

According to the present invention, trans primary chrysanthemic acids can be obtained easily and efficiently.

Next, the method of the present invention will be described in detail.

Examples of the compound represented by the general formula (I) used as a raw material in the present invention include, for example, primary chrysanthemic acid, methyl primary chrysanthemate, ethyl primary chrysanthemate, propyl primary chrysanthemate, and butyl primary chrysanthemate. Examples thereof include cyclohexyl primary chrysanthemate, cyclohexyl methyl primary chrysanthemate, and benzyl primary chrysanthemate.

Further, the cis-primary chrysanthemic acid may be a cis isomer alone or a mixture with a trans isomer in any ratio, but in view of the object of the present invention, the cis isomer alone or the cis isomer is enriched It goes without saying that the significance is exerted when using acids.

As the carboxylic acid bromides used in the present invention, carboxylic acid bromides having 1 to 18 carbon atoms are usually used, for example, acetyl bromide, propionyl bromide, butyryl bromide, isobutyryl bromide, valeryl bromide, isovaleryl bromide, Pivaloyl bromide, hexanoyl bromide, heptanoyl bromide, cyclohexanecarbonyl bromide, octanoyl bromide, nonanoyl bromide, decanoyl bromide, 3-
(2-methylpropenyl) -2,2-dimethylcyclopropanecarbonyl bromide, undecanoyl bromide,
Aliphatic monocarbonyl bromides such as palmitoyl bromide and stearoyl bromide, malonyl dibromide, succinyl dibromide, glutaryl dibromide, adipoyl dibromide, pimeloyl dibromide, suberoyl dibromide, azela oil dibromide, sebacoil dibromide Having an aromatic group such as aliphatic dicarboxylic acid dibromide such as bromide, benzoyl bromide, phenylacetyl bromide, phenylpropionyl bromide, phenylbutyryl bromide, naphthalene carbonyl bromide, phthaloyl dibromide, terephthaloyl dibromide, isophthaloyl dibromide, etc. Acid bromides of mono and dicarboxylic acids are mentioned.

Examples of silicon bromides include lower alkylsilyl bromides such as trimethylsilyl bromide, dimethylsilyl dibromide, methylsilyl tribromide and triethylsilyl bromide, silyl tetrabromide, and the like.

Examples of the S-bromine compounds include thionyl bromide, P-toluenesulfonyl bromide, methanesulfonyl bromide, phenylsulphenyl bromide and the like.

Examples of N-bromo compounds include N-bromosuccinimide, N-bromoacetamide, N-bromopropionamide, N-bromobutyramide and N-bromovaleramide. Among these, carboxylic acid bromides are more preferable, and acetyl bromide, propionyl bromide and the like are more preferable.

The amount of these bromine compounds used is usually in the range of 1/1000 to 1/4 mol per 1 mol of the primary chrysanthemic acid to be treated.

Examples of the azo compound include azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 4,4′-azobis. -4-Cyanopentanoic acid, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-
Examples thereof include azonitriles such as propylazoformamide, azoesters such as methyl azobisisobutyrate and ethyl azobisisobutyrate, and alkylazos such as azo-t-butane. Azonitriles and azoesters are preferably used.

The amount used is usually 1 / mol of the bromine compound.
It is in the range of 20 to 5 mol, preferably 1/10 to 2 mol.

As the peroxide, for example, hydrogen peroxide, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tetrahydrofuran, hydroperoxide produced by oxidation of ethers such as dioxane, Cumene hydroperoxide, hydroperoxides such as diisopropylbenzene hydroperoxide, diacyl peroxides such as benzoyl peroxide and lauroyl peroxide, t-butyl perbenzoate, t-butyl peracetate, diisopropyl peroxydicarbonate, dicyclohexyl Peroxyesters such as peroxydicarbonate, ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide Di -t- butyl peroxide,
Examples thereof include dialkyl peroxides such as dicumyl peroxide and peracids such as peracetic acid. Of these, hydroperoxides, diacyl peroxides and peroxyesters are preferable.

The amount of peroxide used is usually 1 per mol of the bromine compound.
/ 20 to 5 mol, preferably 1/10 to 2 mol.

Further, when carrying out the reaction, it is preferable to use an inert solvent, and as such a solvent, a saturated hydrocarbon,
Aromatic hydrocarbons, their halides, ethers, etc. can be mentioned.

The reaction temperature is arbitrary in the range of -20 ° C to the boiling point of the primary chrysanthemic acid (the boiling point of the solvent used when the solvent is used),
It is usually 0 ° C to 100 ° C.

The time required for the reaction may vary depending on the amount of the bromine compound and the peroxide or the azo compound used and the reaction temperature, but usually several minutes to 10 hours is sufficient to achieve the purpose.

In carrying out the method of the present invention, usually, the first chrysanthemic acid to be treated is mixed with an azo compound or peroxide in the presence of a solvent, and then a bromine compound is added thereto, or It is carried out by dissolving chrysanthemic acid in a solvent and then pouring an azo compound or peroxide and a bromine compound together.

The progress of the reaction can be obtained by sampling a part of the reaction solution and analyzing it by gas chromatography or the like.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Example 1 5.0 g of cis primary chrysanthemic acid and 0.20 g of azobisisobutyronitrile were dissolved in 50 ml of toluene, and a toluene solution of 55 mg of acetyl bromide was added dropwise over 20 minutes while stirring at 80 ° C.

After the reaction, dilute hydrochloric acid was added, and the mixture was stirred and separated.
10% aqueous caustic soda solution was extracted twice, and the resulting aqueous layer was acidified with hydrochloric acid and extracted twice with toluene. The toluene layer is washed with water, dried over sodium sulfate, the solvent is distilled off under reduced pressure, and then the residual liquid is distilled to give a boiling point of 110 to 119 ° C /
4.6 g of a 2.5 mm Hg fraction was obtained. This product was confirmed to be chrysanthemic acid from the infrared absorption spectrum.

As a result of measuring the isomer ratio by gas chromatography,
The cis form was 9.9% and the trans form was 90.1%.

Example 2 0.50 g of cis primary chrysanthemic acid and 47 mg of azobisisobutyronitrile were dissolved in 10 ml of toluene. While stirring at 80 ° C, 59 mg of thionyl bromide was added dropwise, and the mixture was stirred for 20 minutes.

The same treatment as in Example 1 was carried out to obtain 0.4 g of primary chrysanthemic acid. The isomer ratio was 10.7% cis and 89.3 trans.
%Met.

Example 3 To 10.0 g of primary chrysanthemic acid consisting of 19.4% of cis isomer and 80.6% of trans isomer, 20 ml of toluene and 0.58 g of t-butylperbenzoic acid were added, and acetyl bromide (0.1%) was added while stirring at 100 ° C. 37 g of carbon tetrachloride solution was added dropwise, and the mixture was stirred at the same temperature for 20 minutes.

The same treatment as in Example 1 was carried out to obtain 8.3 g of primary chrysanthemic acid. When the isomer ratio was measured, it was 7.0% in cis form and 93.0% in trans form.

Example 4 4.00 g of the same primary chrysanthemic acid used in Example 3 was dissolved in 20.0 ml of toluene, and azobisisobutyronitrile 98 was added.
mg was added, and 91 mg of trimethylsilyl bromide was added dropwise with stirring at 80 ° C. The same treatment as in Example 1 was carried out to obtain 3.68 g of primary chrysanthemic acid. The isomer ratio is cis 7.
It was 0% and the trans form was 93.0%.

Example 5 2.00 g of the same primary chrysanthemic acid used in Example 3 was dissolved in 10.0 ml of chlorobenzene, and t-butylperbenzoic acid of 0.
23 g was added, and 87 mg of trimethylsilyl bromide was added dropwise while stirring at 100 ° C.

The same treatment as in Example 1 was carried out to obtain 1.63 g of primary chrysanthemic acid. The isomer ratio is cis cis 7.7%, trans isomer 92.
It was 3%.

Example 6 2.1 g of the same primary chrysanthemic acid used in Example 3 was added to toluene 1
0.11 g of t-butyl hydroperoxide dissolved in 0 ml
Was added. Trimethylsilyl bromide 0.19 at 20 ° C
g was added, and the mixture was stirred at the same temperature for 20 minutes.

The same treatment as in Example 1 was carried out to obtain 1.9 g of primary chrysanthemic acid. The isomer ratio is 4.2% for cis and 95.8% for trans.
Met.

Example 7 1.0 g of chrysanthemic acid used in Example 3 and 98 mg of azobisisobutyronitrile were dissolved in 10 ml of dioxane. 0.15 g of N-bromosuccinimide was added with stirring at 80 ° C., and the reaction was carried out for 20 minutes.

After the reaction, 1 g of 40% sodium hydroxide aqueous solution was added, and the solvent was distilled off under reduced pressure. Water and toluene were added to the residue, extraction was performed, and the layers were separated. The aqueous layer was neutralized with diluted sulfuric acid, extracted with toluene, and washed with water. Next, the organic layer was concentrated and then distilled to obtain 0.79 g of primary chrysanthemic acid. (Boiling point 110-119 ° C
/2.5mmHg) isomer is cis 4.2%, trans 9
It was 5.8%.

Example 8 1.0 g of the same chrysanthemic acid used in Example 3 and 98 mg of azobisisobutyronitrile were dissolved in 10 ml of toluene. 80
Benzoyl bromide (0.11 g) was added dropwise with stirring at 0 ° C, and the mixture was reacted for 20 minutes.

Analysis of the isomer ratio of this product, cis 5.7%,
The trans form was 94.3%.

Example 9 2.0 g of the same chrysanthemic acid used in Example 3 and 0.15 g of azobisisobutyronitrile were dissolved in 20 ml of toluene.
0.25g adipoyl dibromide with stirring at 80 ° C
Was added dropwise and reacted for 20 minutes.

When the isomer ratio of this product was analyzed, the cis isomer was 7.2%,
The trans form was 92.8%.

Example 10 3.2 g of an ethyl ester of primary chrysanthemic acid consisting of 20.1% of cis isomer and 79.9% of trans isomer and 0.27 g of azobisisobutyronitrile were dissolved in 20 ml of toluene. 80 ° C
While stirring at 0.38 g of trimethylsilyl bromide was added and reacted for 20 minutes.

The reaction solution was washed with a 2% aqueous sodium hydroxide solution and the solvent was distilled off. Then distilled under reduced pressure, boiling point 85 ~ 88 ℃ / 10mm
2.6 g of Hg distillate was obtained.

It was confirmed from the infrared absorption spectrum that this was the ethyl ester of primary chrysanthemic acid.

When the isomer ratio was determined by gas chromatography, the cis isomer was 7.0% and the trans isomer was 93.0%.

Example 11 Same primary chrysanthemic acid ethyl ester used in Example 10
Chlorobenzene 10 with 32 g and benzoyl peroxide 50 mg
dissolved in ml. 29 mg of acetyl bromide was added at 80 ° C. and the reaction was carried out for 20 minutes.

A part of this product was sampled and the isomer ratio was measured to find that it was 7.0% in the cis form and 93.0% in the trans form.

Example 12 0.32 g of ethyl cis primary chrysanthemate and 30 mg of azobisisobutyronitrile were dissolved in 10 ml of toluene, 49 mg of trimethylsilyl bromide was added, and the mixture was reacted for 20 minutes. Analysis of the isomer ratio of this product revealed that the cis isomer was 31.4% and the trans isomer was 68.6%.

Claims (1)

[Claims] 1. A general formula (In the formula, R represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group or an aralkyl group.) To the racemic-cis or racemic-cis / trans mixed primary chrysanthemic acid, an azo compound or A racemic compound characterized in that at least one bromine compound selected from the group consisting of carboxylic acid bromides, silicon bromides, S-bromo compounds and N-bromo compounds is allowed to act in the presence of peroxide for trans-conversion. -Method for producing trans primary chrysanthemic acids.