JPH0469134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 2-(4-alkoxyphenyl)-2-
This invention relates to a method for producing methylpropyl chloride.

More specifically, the general formula (); (In the formula, R ² represents a lower alkyl group) 2-(4-acyloxyphenyl)-2-methylpropyl chloride and an alkylating agent are mixed without a solvent or in a water-soluble ether solvent with a base and General formula () characterized in that the reaction is carried out in the presence of a phase transfer catalyst; The present invention relates to a method for producing 2-(4-alkoxyphenyl)-2-methylpropyl chloride represented by the formula (wherein R ¹ represents a lower alkyl group or a cycloalkyl group).

2-(4-alkoxyphenyl)-2-methylpropyl chlorides are useful compounds in various industrial fields, and are particularly useful as intermediates for the production of agricultural chemicals, ie, insecticides.

For example, 2-(4-alkoxyphenyl)-2-
Methylpropyl chlorides are 3-phenoxybenzyl 2-aryl-2-methylpropyl ethers (JP-A-57-72928; JP-A-57-72928; JP-A-57-72928;
32840; JP-A-57-64632) is particularly useful as an intermediate for production.

As a method for producing 2-(4-alkoxyphenyl)-2-methylpropyl chloride, (1) alkoxybenzenes and 3-chloro-2-methyl-1
-There is a method of manufacturing it from propene.

For example, there is a method of synthesis from anisole and 3-chloro-2-methyl-1-propene in the presence of concentrated sulfuric acid. (chem.Ber., 94 , 2609 (1961)) In this method, the target 2-(4-methoxyphenyl)-2-methylpropyl chloride is produced simultaneously with the isomer 2-(2-methoxyphenyl)-2. -Since only about 1/2 to 1/3 of methylpropyl chloride is produced, precise distillation operations are required for separation and purification.

Similar results can also be obtained with alkoxybenzenes other than anisole.

Therefore, the desired 2-
The industrial production of (4-alkoxyphenyl)-2-methylpropyl chloride is very disadvantageous.

Other production methods include (2) 2-(acyloxyphenyl)-2-methylpropyl chloride is reacted with an alkylating agent and a base in the presence or absence of an inert solvent.
There is a method for producing -(alkoxyphenyl)-2-methylpropyl chloride (Japanese Patent Application Laid-Open No. 1986-
Publication No. 88336).

Specifically, this method uses 2-(alkoxyphenyl)-2 of the target compound in an inert solvent.
-The reaction is carried out in an aprotic polar solvent such as dimethylformamide or sulfolane, which has a boiling point close to that of methylpropyl chloride. If the reaction is carried out in a solvent other than the above, the yield will be poor; if the reaction is carried out in the above solvent, after the reaction, the reaction solution is drained into water and extracted with benzene or carbon tetrachloride. After washing the obtained organic layer with water and drying,
Crude 2-(alkoxyphenyl)-2-methylpropyl chlorides are produced by evaporating the solvent (benzene or carbon tetrachloride).

However, in this method, in order to recover the target product from the liquid discharged into water after the reaction is completed, the non-pyrotic polar solvent used in the reaction has high solubility in both the aqueous layer and the organic layer. Requires large amounts of extraction solvent. In addition, recovery of these aprotic polar solvents discharged into water requires complicated steps and a large amount of energy, so it cannot be said that this is a preferred method for industrial production.

The present inventors have made extensive studies to overcome the difficulties in these conventional methods.

As a result, 2-(4
-Acyloxyphenyl)-2-methylpropyl chloride and an alkylating agent are reacted without a solvent or in a water-soluble ether solvent in the presence of a base and a phase transfer catalyst. (4-alkoxyphenyl)-2-
The present invention has been completed by discovering a method for producing methylpropyl chloride industrially easily and economically with high purity and high yield.

In the method of the present invention, the general formula (); Specifically, 2-(4-alkoxyphenyl)-2-methylpropyl chloride represented by (wherein R ¹ represents the above-mentioned meaning) is 2-(4-methoxyphenyl)-2- methylpropyl chloride,
2-(4-ethoxyphenyl)-2-methylpropyl chloride, 2-(4-n-propoxyphenyl)
-2-Methylpropyl chloride, 2-(4-isopropoxyphenyl)-2-methylpropyl chloride, 2-(4-n-butoxyphenyl)-2-methylpropyl chloride, 2-(4-isobutoxyphenyl) -2-methylpropyl chloride, 2-
(4-sec-butoxyphenyl)-2-methylpropyl chloride, 2-(4-pentyloxyphenyl)-2-methylpropyl chloride, 2-(4-hexyloxyphenyl)-2-methylpropyl chloride, 2- Examples include compounds such as (4-cyclopentyloxyphenyl)-2-methylpropyl chloride and 2-(4-cyclohexyloxyphenyl)-2-methylpropyl chloride.

In the method of the present invention, the general formula (); 2-(4-acyloxyphenyl)-
The substituent R ² of 2-methylpropyl chloride represents a lower alkyl group having 1 to 6 carbon atoms, but a methyl group is preferred in industrial production methods.

The base used in the method of the present invention refers to oxides, hydroxides and carbonates of alkali metals or alkaline earth metals, and organic amines, specifically sodium hydroxide, potassium hydroxide, magnesium oxide. , calcium oxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, calcium carbonate, triethylamine, pyridine, and the like. These bases can be used in liquid or solid state. Preferred bases include solid alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The shape thereof may be granular, flake, powder, or fine powder.

The amount used is expressed by the general formula (2-
The amount is 1.5 to 10 mol, preferably 2.0 to 3.0 mol, per 1.0 mol of (4-acyloxyphenyl)-2-methylpropyl chloride. If it is 2.0 mol or less, the yield will decrease, and if it is 3.0 mol or more, it will not affect the yield reduction at all, but 3.0 mol or more will not affect the yield reduction.
It is industrially desirable to have a molar value or less.

The alkylating agents used in the method of the present invention are dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, methyl iodide, methyl bromide, methyl chloride, ethyl iodide, ethyl bromide, ethyl chloride, isopropyl chloride, and bromide. Alkyl halides such as isopropyl, propyl chloride, propyl bromide, butyl chloride, sec-butyl chloride, iso-butyl chloride, pentyl chloride, hexyl chloride, and cycloalkyl halides such as cyclopentyl chloride, cyclopentyl bromide, cyclohexyl chloride, cyclohexyl bromide, etc. Among them, diethyl sulfate, alkyl halides and cycloalkyl halides are preferred.

The amount used is expressed by the general formula (2-
The amount is 1.5 mol or more per 1.0 mol of (4-acyloxyphenyl)-2-methylpropyl chloride, but 2.0 mol to 3.0 mol is preferable from the viewpoint of yield and economy.

The phase transfer catalyst used in the method of the present invention has the following general formula (); (In the formula, M is a _{nitrogen or} phosphorus _{atom ;} represents an aryl-alkyl group), and representative examples include the following compounds.

Tetramethylammonium, tetraethylammonium, tetrabutylammonium, trimethylphenylammonium, triethylphenylammonium, tributylphenylammonium,
Quaternary ammonium salts such as chloride, bromide or iodide of trimethylbenzylammonium, triethylbenzylammonium, tributylbenzylammonium, trimethylphenylethylammonium, triethylphenylethylammonium, tributylphenylethylammonium, and tetramethylphosphonium, tetraethylphosphonium, tetra Butylphosphonium, trimethylphenylphosphonium, triethylphenylphosphonium, tributylphenylphosphonium, trimethylbenzylphosphonium,
These include quaternary phosphonium salts such as chloride, bromide, and iodide of triethylbenzylphosphonium, trimethylphenylethylphosphonium, triethylphenylethylphosphonium, and tributylphenylethylphosphonium. Among these compounds, the most preferred alkyl groups for R ₃ , R ₄ , R ₅ and R ₆ are methyl, ethyl and butyl groups, the most preferred aryl group is phenyl, and the most preferred aryl-alkyl group is benzyl.

These quaternary ammonium salts or quaternary phosphonium salts used in the method of the present invention can be used in a solid or liquid state (for example, a 50% aqueous solution).

Other phase transfer catalysts used in the method of the present invention are crown ethers. The following compounds are representative examples. 12
- Crown-4 (12-crown-4), 15-crown-5 (15-crown-5), 18-crown-6 (18-
crown-6), dibenzo-18-crown-6
(dibenzo-18-crown-6), dicyclohexano-18-crown-6 (dicyclohexano-18-crown-6),
crown-6), dicyclohexano-24-crown-8 (dicyclohexano-24-crown-8), and the like.

The amount of the phase transfer catalyst used in the method of the present invention is preferably 0.001 to 1.0 parts by weight per 1 part by weight of the 2-(4-acyloxyphenyl)-2-methylpropyl chloride represented by the general formula (). is 0.01 to 0.5 parts by weight.

In the production method of the present invention, there is no significant difference in yield and product purity whether or not a water-soluble ether is used as a solvent, and from an industrial standpoint, a solvent-free method is preferable. .

As the water-soluble ethers used if desired, dioxane and tetrahydrofuran are preferable, and tetrahydrofuran is particularly preferable.

Regarding the reaction temperature, at low temperatures the reaction rate is slow and impractical, and at high temperatures there is a problem with the stability of the product.
-200°C, preferably 20-100°C is suitable.

Next, a general embodiment of the manufacturing method of the present invention will be described.

Charge a reaction vessel with 2-(4-acyloxyphenyl)-2-methylpropyl chloride, phase transfer catalyst, alkylating agent, and base (water-soluble ethers may be added if necessary).

Next, after heating to a predetermined temperature and stirring for a predetermined time,
In the case of no solvent, water is added to the reactor to dissolve the precipitated salt and decompose the organic layer. The obtained organic layer is washed with water and dehydrated. This product has high purity and can be used as it is as a raw material for agricultural chemicals such as the above-mentioned insecticides and acaricides, but it may be further purified by distillation if necessary. .

When water-soluble ethers are used, the precipitated salts are removed by filtration, the solvent is recovered by distillation, etc., and the resulting crude product is washed with water and dehydrated. Similar to the solvent-free case, this product has high purity and can be used as a raw material for agricultural chemicals and the like as it is, but it may be further purified by distillation if necessary.

The reaction is usually carried out at normal pressure, but it goes without saying that it can also be carried out under reduced pressure or increased pressure.

Next, the manufacturing method of the present invention will be explained in more detail with reference to Reference Examples and Examples.

Reference example 2-(4-acetoxyphenyl)-2methylpropyl chloride 34.0g, diethyl sulfate 57.8g at 20℃
26.3 g of 95% caustic potash were placed in a flask and stirred at 40° C. for 6.0 hours. The reaction mixture was cooled to room temperature, 40 ml of water was added, and after stirring for 1.0 hour,
The organic layer was separated, washed with water, dehydrated and dried under reduced pressure to obtain 34.8 g of a crude product.

Results of analysis by gas chromatography, 2
It contained 42.2% of -(4-ethoxyphenyl)-2-methylpropyl chloride. Yield 46.0%.

Example 1 340 g of 2-(4-acetoxyphenyl)-2-methylpropyl chloride, 578 g of diethyl sulfate at 20°C
263 g of 96% caustic potash were placed in a flask, and then 85.0 g of a 20% aqueous solution of triethylbenzylammonium chloride was added dropwise over 10 minutes at 30°C. The mixture was stirred at 40° C. for 6.0 hours, cooled to room temperature, 40 ml of water was added, and stirred for 1.0 hours. The organic layer was separated to yield 450 g of oil. Then,
Add 8% aqueous sodium hydroxide solution to the obtained oil.
450g was added and stirred at 80°C for 4.0 hours to completely decompose the diethyl sulfate contained in the oil.

After cooling the reaction mixture to room temperature, the organic layer was separated,
After washing the obtained oily substance with water, it was heated under reduced pressure (90℃/5mm
Hg) to obtain 303 g of a crude product. As a result of analysis by gas chromatography, 2-(4-ethoxyphenyl)-2-methylpropyl chloride
It contained 96.5%. Yield 91.6%.

Example 2 2-(4-acetoxyphenyl)-2 at 20-25°C
- 440 g of methylpropyl chloride, diethyl sulfate
Put 748 g, 340 g of 96% flaky caustic potash, and 44.0 g of triethylbenzylammonium chloride as a phase transfer catalyst into a flask, and add water at 20 to 25°C.
88.0g was dropped.

The mixture was stirred at 40°C for 5.0 hours and then at 60°C for 0.5 hours. Cool the reaction mixture to 30°C, add 500ml of water,
The precipitated salt was dissolved. Separate the organic layer and remove the oil
Obtained 525g. Next, wash with 3.5% hydrochloric acid solution, 3% sodium hydroxide solution, and water in order to remove the oily substance.
I got g. Water and light boiling components were removed under reduced pressure (80° C./0.2 mmHg) to obtain 420.6 g of crude product. As a result of analysis by gas chromatography, 2-
It contained 89.0% (4-ethoxyphenyl)-2-methylpropyl chloride. Yield 90.6%.

410.0g of the crude product with a purity of 89.0% obtained above was distilled under reduced pressure (88℃~89℃/0.2mmHg) to obtain purified 2-
350.4 g of (4-ethoxyphenyl)-2-methylpropyl chloride was obtained. As a result of analysis by gas chromatography, the purity was 98.0%.

Example 3 2-(4-acetoxyphenyl)-2-methylpropyl chloride 613 in tetrahydrofuran 3
g, triethylbenzylammonium bromide
100 g of 96% caustic potash flakes and 747 g of ethyl bromide were added, and the mixture was stirred at 50° C. for 7.5 hours. After the reaction mixture was cooled to room temperature, the precipitated salt was removed by filtration. After distilling and recovering tetrahydrofuran from the resulting liquid under normal pressure, the mixture was washed with dilute hydrochloric acid, dilute alkaline water, and water in this order, and then dried over anhydrous sodium sulfate.

The desiccant was removed by filtration, leaving 557 g of crude product.
I got it. Analysis by gas chromatography revealed that it contained 95.0% of 2-(4-ethoxyphenyl)-2-methylpropyl chloride. Yield 92.0%.

Example 4 45.3 g of 2-(4-acetoxyphenyl)-2-methylpropyl chloride, 35.0 g of 96% flaked caustic potash, and tetrabutylammonium chloride.
11.3g of 20% aqueous solution and 54.5g of ethyl bromide at 10℃
The mixture was then placed in a flask and stirred at 40°C for 4.0 hours.
After cooling the reaction mixture to room temperature, water was added and extracted with hexane. Dilute the extract with dilute hydrochloric acid water, dilute alkaline water,
It was washed successively with water and dried over anhydrous sodium sulfate.

Hexane was distilled off under reduced pressure to obtain 4.03 g of crude product. The result of gas chromatography analysis of this product was 92.8%. Yield 88.0%.

Example 5 The same procedure as in Example 4 was carried out except that 60.3 g of hexyl chloride was used instead of 54.5 g of ethyl bromide to obtain 51.0 g of a crude product.

Results of gas chromatography analysis 2-
It contained 89.3% (4-hexyloxyphenyl)-2-methylpropyl chloride.

Yield 84.9%.

Claims (1)

[Claims] 1 General formula (); (In the formula, R ² represents a lower alkyl group) 2-(4-acyloxyphenyl)-2-methylpropyl chloride and an alkylating agent were mixed without a solvent or in a water-soluble ether solvent with a base and General formula () characterized in that the reaction is carried out in the presence of a phase transfer catalyst; A method for producing 2-(4-alkoxyphenyl)-2-methylpropyl chloride represented by the formula (wherein R ¹ represents a lower alkyl group or a cycloalkyl group). 2. The manufacturing method according to claim 1, wherein in the general formula (), R ² is a methyl group. 3. The manufacturing method according to claim 1, which comprises reacting 2-(4-acyloxyphenyl)-2-methylpropyl chloride represented by the general formula () with an alkylating agent without a solvent. . 4. The manufacturing method according to claim 1, wherein the alkylating agent is diethyl sulfate or an alkyl halide. 5. The manufacturing method according to claim 1, wherein the base is a solid alkali.