JPH0469135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl halides. More specifically, the general formula (); (wherein, X is a halogen atom and R is an alkyl group) is 2-halogenoalkoxybenzene represented by the general formula () in the presence of a boron trifluoride phosphate complex; General formula () characterized by reacting methallyl halide represented by (in the formula, Y represents a halogen atom); The present invention relates to a method for producing 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl halides represented by the formula (wherein X, Y, and R each have the above-mentioned meanings).

2-(3-halogeno-4-alkoxyphenyl)
-2-Methylpropyl halides are useful compounds in various industrial fields. For example, it is useful as an intermediate for the production of agricultural chemicals, especially as an intermediate for insecticides.

Recently, it has high insecticidal and acaricidal activity, fast-acting,
2-Aryl-2-methylpropyl ethers with excellent residual efficacy have been disclosed as new insecticides (Japanese Patent Application Laid-Open No. 57-72928 and JP-A No. 57-64632).
Publication No.). 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl halides are particularly 3-phenoxybenzyl 2-(3-halogeno-4
It is useful as an intermediate in the production of -alkoxyphenyl)-2-methylpropyl ethers. 3-Phenoxybenzyl 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl ethers are themselves useful as insecticides and acaricides; It is also an important compound as an intermediate for enoxybenzyl 2-(4-alkoxyphenyl)-2-methylpropyl ethers.

As a method for producing such 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl halides, 2-(3-halogeno-4-acyloxyphenyl)-2-methylpropyl halides are converted into alkyl There is a way to convert it into
Publication No. 88336).

However, this method has the disadvantage that it requires a large number of steps for producing raw materials. Therefore, as a method using easier-to-produce starting materials, we filed an application for a Friedel-Crafts reaction of 2-halogenoalkoxybenzene and methallyl halide in the presence of sulfuric acid or trifluoromethanesulfonic acid. , Special Publication No. 4-39449). This method is effective in that raw material compounds are easily available and the number of reaction steps is small.

However, in this method, although methallyl halide is preferentially introduced at the para position to the alkoxy group of 2-halogenoalkoxybenzene, 3.5 to 5% of the metall halide is substituted at the ortho and meta positions.
The yield is not very high. Therefore, from the standpoint of purification and separation, it has been desired to suppress the production of these isomers and to improve the yield.

The present inventors have made extensive studies to improve these points. As a result, 2 expressed by the general formula ()
- When halogenoalkoxybenzene is reacted with methallyl halide in the presence of a boron trifluoride phosphate complex, the formation of positional isomers, ortho- and meta-substituted products, is extremely suppressed, and the desired 2
-(3-halogeno-4-alkoxyphenyl)-2
- It was discovered that methylpropyl halides can be obtained in high yield, and the present invention was completed.

That is, the present invention is based on the general formula (); (wherein, X is a halogen atom and R is an alkyl group) is 2-halogenoalkoxybenzene represented by the general formula () in the presence of a boron trifluoride phosphate complex; (wherein, Y represents a halogen atom) 2-(3-halogeno-4-alkoxyphenyl)-2- This is an industrial method for producing methylpropyl halides.

According to the method of the present invention, methallyl halide is
The alkoxy group of 2-halogenoalkoxybenzene can be introduced only to the para position with extremely high selectivity, and the desired product can be produced in an extremely high yield. Therefore, the method of the present invention is an industrially excellent manufacturing method.

The raw material compound used in the present invention is 2-halogenoalkoxybenzene represented by the general formula ().

In the general formula (), R is an alkyl group, and examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-
Examples include butyl, pentyl, isopentyl, neopentyl groups, and the like. X is a halogen atom,
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. 2 expressed by the general formula ()
- Specific examples of the halogenoalkoxybenzene include 2-fluoroanisole, 2-fluorophenethole, 2-fluoro-n-propoxybenzene, 2-chloroanisole, 2-chlorophenetol, 2-chloro-n-propoxybenzene. ,2
-chloro-isopropoxybenzene, 2-chloro-butoxybenzene, 2-chloro-pentyloxybenzene, 2-bromoanisole, 2-bromophenethole, 2-bromo-propoxybenzene and the like. These 2-halogeno-alkoxybenzenes represented by the general formula () can be produced industrially at low cost. For example, in the case of 2-chloroanisole, 2-chlorophenol can be methylated with an alkylating agent or O-di It can be easily obtained by conventional methods such as methanolysis of chlorobenzene.

The other raw material compound used in the present invention is methallyl halide represented by the above general formula (). In the general formula (), Y is a halogen atom, and examples include a chlorine atom and a bromine atom. These methallyl halides can be produced industrially at low cost by known methods. Methallyl halide and 2
-The reaction with halogenoalkoxybenzene is carried out as follows.

Methallyl halide is used in an amount of 0.1 to 10 mol, preferably 0.5 to 5 mol, and more preferably 0.8 to 1.5 mol per mol of 2-halogenoalkoxybenzene represented by the general formula ().

The catalyst used in the process of the invention is a boron trifluoride phosphate complex.

The amount of boron trifluoride phosphate complex used may be large, but it is 0.001 to 1 mole of methallyl halide.
10 moles are used, preferably 0.01 to 5 moles.

The reaction temperature is -30°C to 180°C, preferably -15°C
~100℃ range. This reaction can be carried out under normal pressure or increased pressure.

In the method of the present invention, this reaction can be carried out without a solvent, but an inert organic solvent may be used for this reaction. Examples of such organic solvents include aromatic hydrocarbon solvents such as dichlorobenzene and nitrobenzene, aliphatic hydrocarbon solvents such as hexane, pentane, octane, etc., as well as dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, and acetonitrile. , nitromethane, carbon disulfide, etc.

After the reaction is completed, the product can be obtained by extraction from the reaction mixture using a conventional method. Furthermore, if desired, the boron trifluoride phosphate complex used once can be used repeatedly. That is, after the completion of the reaction, if necessary, an aliphatic hydrocarbon solvent such as hexane, octane, etc. is added, and the boron trifluoride phosphate complex separated into two layers is separated from the reaction mixture, and this is again used as the catalyst for this reaction. Use as. By repeating this operation, the catalyst can be used repeatedly. Hereinafter, the present invention will be explained in more detail with reference to Reference Examples and Examples.

Example 1 2-chlorophenetol 40.0g (0.255mol)
and 11.3 g of boron trifluoride phosphate complex (48% boron trifluoride W/W) was stirred at an internal temperature of 20°C. 17.2 g (0.190 mol) of methallyl chloride was added dropwise to the mixture over 4 hours while maintaining the internal temperature at 20°C, and the mixture was subsequently stirred at the same temperature for 5 hours. 100 ml of saturated brine and 100 ml of hexane were added to the reaction solution, and the mixture was thoroughly shaken in a separating funnel. The organic layer was washed with 50 ml of saturated brine, dried over anhydrous sodium sulfate,
Concentration under reduced pressure yielded 57.0 g of a colorless liquid. As a result of quantitative analysis (internal standard method) of this substance by gas chromatography, it was found that this substance had the desired 2
It contained 42.4 g of -(3-chloro-4-ethoxyphenyl)-2-methylpropyl chloride.
The yield was 90.2% (based on methallyl chloride), and the target product and isomers [2-(3-chloro-2-ethoxyphenyl)-2-methylpropyl chloride and 2-[4-chloro-3-ethoxyphenyl] )-2-
The content ratios of methylpropyl chloride] were 90.0% and 1.0%, respectively. This crude product was purified by vacuum distillation, and the desired 2-(3-chloro-4
40.8 g of -ethoxyphenyl)-2-methylpropyl chloride was obtained.

Purity (gas chromatography area%) 98.5% Yield 85.6% (based on methallyl chloride) Example 2 2-chlorophenetol 40.0 g (0.255 mol)
and 11.6 g of boron trifluoride phosphate complex (48% boron trifluoride w/w) was stirred at an internal temperature of 5°C. To this, 17.2 g (0.190 mol) of methallyl chloride was added dropwise over 2.5 hours while maintaining the same temperature, and the mixture was subsequently stirred at the same temperature for 2.5 hours. After the reaction, post-treatment was carried out in the same manner as in Example 1 to obtain a colorless liquid of 56.5
I got g. From quantitative analysis using gas chromatography (internal standard method), this product has the objective 2-
It contained 40.9 g of (3-chloro-4-ethoxyphenyl)-2-methylpropyl chloride. Yield 87.0%. Or, the target product and isomer [2-(3-
Chloro-2-ethoxyphenyl)-2-methylpropyl chloride and 2-(4-chloro-3-
The content ratio of ethoxyphenyl)-2-methylpropyl chloride is 98.4% and 1.6%, respectively.
It was hot.

Example 3 2-chlorophenetol 20.0 (0.128 mol), boron trifluoride phosphate complex (48% boron trifluoride w/
w) A mixture of 6.5 g and 13.2 g of hexane was stirred at an internal temperature of 20°C. In this, methallyl chloride
11.6 g (0.128 mol) was added dropwise over 2 hours while maintaining the same temperature, and then stirred at the same temperature for 2 hours. From the reaction solution separated into two layers, the lower catalyst layer was separated, and the organic layer was washed with a saturated aqueous solution of sodium chloride (50ml x 2 times), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to 31.6g of colorless liquid. I got it.
As a result of quantitative analysis (internal standard method) of this material by gas chromatography, the target 2-
It contained 25.3 g of (3-chloro-4-ethoxyphenyl)-2-methylpropyl chloride. Yield 80.1%. Also, the target product and isomer [2-(3-chloro-2-ethoxyphenyl)-2-methylpropyl chloride and 2-(4-chloro-3-ethoxyphenyl)-2-methylpropyl chloride]
The content ratios were 98.2% and 1.8%, respectively.

Example 4 After reaction in the same manner as in Example 1, 40 ml of hexane was added to the reaction solution, and the boron trifluoride phosphate complex in the lower layer was recovered from the reaction solution which was separated into two layers. this catalyst
10.5 g of 2-chlorophenetol, 37.2 g of 2-chlorophenetol, and 16.0 g of methallyl chloride were reacted in the same manner as in Example 1. Add 40ml of hexane to the reaction solution,
Separate the organic layer from the reaction mixture separated into two layers and wash with a saturated aqueous solution of sodium chloride (50ml x 2)
After drying over anhydrous sodium sulfate, the residue was concentrated under reduced pressure to obtain 54.6 g of a colorless liquid. Quantitative analysis using gas chromatography (internal standard method) revealed that the target product was 2-(3-chloro-4-ethoxy-phenyl).
It was found that it contained 38.2 g of -2-methylpropyl chloride. Yield 87.4%. The content ratios of the target product and the isomer were 98.8% and 1.2%.

Example 5 2-fluorophenetol 32.4g (0.235mol)
A mixture of 15.0 g of boron trifluoride phosphate complex (48% boron trifluoride w/w) was stirred at an internal temperature of 20°C. 20.0 g (0.221 mol) of methallyl chloride was added dropwise to this over 2 hours while keeping the internal temperature at 20°C, and the mixture was subsequently stirred at the same temperature for 2 hours. The reaction solution was post-treated in the same manner as in Example 1 to obtain 52.0 g of colorless liquid.
I got it. This product was purified by vacuum distillation, and the desired 2-(3-fluoro-4-ethoxyphenyl)-2
-46.3 g of methylpropyl chloride were obtained.

Purity (gas chromatography area ratio) 99.8% Yield 90.6% (based on methallyl chloride), δCCl ₄ TMS (ppm): 1.37 (6H, s), 1.40 (3H, t, J = 7Hz),
3.48 (2H, s), 4.02 (2H, g, J=7Hz), 6.6
~7.1 (3H, m).

νneat max (cm￣ ¹ ): 2980, 1520, 1310, 1280, 1140, 1045.

Calculated _{for C12H16ClFO} : C, 62.47; H, 6.99; Cl, 15.37; F.8.24%.

measured value: C, 62.18; H, 6.97; Cl, 15.53; F, 8.21%.

Claims (1)

[Claims] 1 General formula (); 2-halogeno-alkoxybenzene represented by (wherein, X is a halogen atom and R is an alkyl group) in the presence of a boron trifluoride phosphate complex, general formula (); General formula () characterized by reacting methallyl halide represented by (in the formula, Y represents a halogen atom); A method for producing 2-(3-halogeno-4-alkoxyphenyl)-2-methylpropyl halides represented by the formula (wherein R, X and Y each have the above-mentioned meanings).