JPH0443055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-(4-halogenophenyl)-2-methylpropyl halides. More specifically, halogenobenzene and general formula () in the presence of trifluoromethanesulfonic acid; 3-halogeno-2-methyl- (wherein, Y represents a chlorine atom or a bromine atom)
General formula () characterized by reacting with 1-propene; (In the formula, X represents a halogen atom and Y represents the above meaning.) 2-(4-halogenophenyl)-2-
This invention relates to a method for producing methylpropyl halides.

2-(4-halogenophenyl)-2-methylpropyl halides are useful compounds in various industrial fields, and are particularly useful as intermediates in the production of agricultural chemicals, that is, as intermediates in insecticides.

For example, 2-(4-halogenophenyl)-2-methylpropyl halides are a new insecticide, 3-
It is particularly useful as an intermediate in the production of phenoxybenzyl 2-aryl-2-methylpropyl ethers (JP-A-56-154427, JP-A-57-64632).

Such 2-(4-halogenophenyl)-2-
The method for producing methylpropyl halides is as follows:
Several proposals have been made so far.

Typical examples include (1) a method in which 4-t-butylhalogenobenzene is chlorinated with sulfuryl chloride in the presence of a small amount of benzoyl peroxide; (Chem.Ber., 94 , 2609
(1961). ).

(2) A method in which 4-t-butylhalogenobenzene is reacted with chlorine under irradiation with light. (Unexamined Japanese Patent Publication No. 57-154134
Publication No. ) (3) A method in which halogenobenzene and 3-chloro-2-methyl-1-propene are reacted in the presence of concentrated sulfuric acid.

(a) Neftekhimiya, 2 , 776-83 (1962). Chemical Abstracts, 59 , 482c (1963). (b) Neth.Appl.6601685; Chemical abstracts, 66 , 2413r (1967). and so on. However, although method (1) has a relatively high yield of 79% of the product 2-(4-chlorophenyl)-2-methylpropyl chloride, this type of radical reaction is very dangerous to carry out. It is accompanied by

That is, in carrying out this reaction, the raw materials 4-t-butylhalogenobenzene, sulfuryl chloride, and a small amount of benzoyl peroxide as a radical initiator are charged all at once into a flask, and then the temperature is started to rise.

The reaction starts at around 100°C, then rapidly progresses and ends in a short time. At the same time, sulfuryl chloride and sulfur dioxide gas are rapidly generated in a short period of time, and there is always a risk of bumping accidents in small-scale flask experiments in the laboratory.

Therefore, when manufactured industrially using this method,
This method cannot be implemented because the reaction cannot be controlled.

Method (2) improves these drawbacks of method (1), but increasing the conversion rate lowers the selectivity, so the conversion rate must be kept below 60 to 70%, and the selectivity must be 80%. % or less, the single yield rate is
It is less than 50%, so it is not necessarily an advantageous method.

In addition, both methods (1) and (2) use t-butylhalogenobenzene as a raw material, and in the case of industrial production, t-butylhalogenobenzene is
Butylation or nuclear halogenation of t-butylbenzene is required, which increases raw material costs, equipment costs, etc., and is not necessarily an industrially advantageous method.

In addition, method (3) produces 2-(halogenophenyl)-2-methylpropyl chloride in one step from halogenobenzene and 3-chloro-2-methyl-1-propene in the presence of concentrated sulfuric acid. Although advantageous, it has the disadvantage of a low yield of less than 20-25%.

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

As a result, halogenobenzene and 3-halogeno-
The present invention was completed by discovering a method for producing 2-(4-halogenophenyl)-2-methylpropyl halides in high yield from halogenobenzene in one step by reacting it with 2-methyl-1-propene.

That is, the present invention provides general formula () in the presence of trifluoromethanesulfonic acid; (In the formula, Y represents the above meaning.) 3-halogeno-2-methyl-1-propene and halogenobenzene are reacted to obtain the desired general formula (); (In the formula, X and Y represent the above meanings.) 2-(4-halogenophenyl)-2-
Methylpropyl halides can be produced simply and economically. The halogenobenzenes used in the present invention are chlorobenzene, bromobenzene, fluorobenzene, and iodobenzene. In addition, 3-halogeno-2-methyl-1-propene, which is generally represented by (), is 3-chloro-2-propene.
-methyl-1-propene and 3-bromo-2-
Methyl-1-propene.

In addition, 2-(4-halogenophenyl)-2-methylpropyl halide produced in the present invention has the general formula (), (In the formula, X and Y represent the above-mentioned meanings.) Specifically, 2-(4-fluorophenyl)-2-methylpropyl chloride, 2-(4-fluorophenyl)- 2-Methylpropyl bromide, 2-(4-chlorophenyl)-2-methylpropyl chloride, 2-(4-chlorophenyl)-2-methylpropyl bromide, 2-(4-bromophenyl)-2-methylpropyl chloride, 2- Examples include compounds such as (4-bromophenyl)-2-methylpropyl bromide, 2-(4-iodophenyl)-2-methylpropyl chloride, and 2-(4-iodophenyl)-2-methylpropyl bromide.

In the method of the present invention, the use of a solvent is not necessarily necessary due to the excessive use of halogenobenzene as a raw material, but carbon disulfide, nitrobenzene,
It is possible to use solvents such as o-dichlorobenzene.

In the method of the present invention, the amount of halogenobenzene used is 0.1 to 20 parts, preferably 1.0 to 10 parts, per 1 part of 3-halogeno-2-methyl-1-propene.

The amount of trifluoromethanesulfonic acid used in the method of the present invention is 0.01 to 100 parts, preferably 0.01 to 20 parts, per part of 3-halogeno-2-methyl-1-propene.

In the method of the present invention, the reaction temperature is -10°C to 150°C.
°C, preferably 0 °C to 100 °C. Further, although it is usually carried out at normal pressure, it goes without saying that it can also be carried out under reduced pressure or increased pressure.

In the method of the present invention, after the completion of the reaction, water is added, the liquid is separated, and the target 2-(4-halogenophenyl)-2-methylpropyl halide is obtained by washing with dilute alkaline water and water in that order, and distilling or other operations. Obtainable.

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

Example 1 168.9 g of chlorobenzene and 13.6 g of trifluoromethanesulfonic acid were placed in a flask and stirred.
3-chloro-2-methyl-1-propene at 50℃
45.3g was added dropwise over 2.0 hours. After dropping, 50℃
It was kept for an additional 1.0 hour. After cooling to room temperature, water was added to the reaction mixture and stirred for 10 minutes. The organic layer was separated, washed successively with dilute alkaline water and water, and dried over anhydrous sodium sulfate. Then distilled under reduced pressure,
77.4 g of a fraction with a bp of 113-114°C/8 mmHg was obtained.

The purity of 2-(4-chlorophenyl)-2-methylpropyl chloride is 97.3% (gas chromatography analysis results).

Example 2 314.4 g of bromobenzene and 9.0 g of trifluoromethanesulfonic acid were placed in a flask, and while stirring,
3-chloro-2-methyl-1-propene at 20℃
45.3g was added dropwise over 3.0 hours.

The reaction was further continued at the same temperature for 2.0 hours, and then cooled to room temperature. After adding water to the reaction mixture and stirring for 10 minutes, the organic layer was separated, washed successively with dilute alkaline water and water, and dried over anhydrous sodium sulfate.

Distillation was performed under reduced pressure to obtain 62.4 g of a fraction with a bp of 121-124°C/1.0 mmHg.

Purity of 2-(4-bromophenyl)-2-methylpropyl chloride is 96.7% (gas chromatography analysis results).

Example 3 45.3 g of trifluoromethanesulfonic acid was added to 480 g of fluorobenzene, and 90.6 g of 3-chloro-2-methyl-1-propene was added to the mixture at 15°C with stirring.
was added at 3.0 hours. After continuing the reaction for further 3.0 hours at the same temperature, the mixture was poured into 500 g of water. After stirring for 10 minutes,
The organic layer was separated, washed successively with dilute alkaline water and water, and dried over anhydrous sodium sulfate. Distillation was carried out under reduced pressure to obtain 114.2 g of a fraction with a bp of 103-106°C/10 mmHg.

The purity of 2-(4-fluorophenyl)-2-methylpropyl chloride is 96.8% (gas chromatography analysis result).

Claims (1)

[Claims] 1 Halogenobenzene and general formula () in the presence of trifluoromethanesulfonic acid; 3-halogeno-2-methyl- (wherein, Y represents a chlorine atom or a bromine atom)
General formula () characterized by reacting with 1-propene; (In the formula, X represents a halogen atom and Y represents the above meaning.) 2-(4-halogenophenyl)-2-
Method for producing methylpropyl halide. 2. The production method according to claim 1, wherein the halogenobenzene is chlorobenzene, fluorobenzene, or bromobenzene. 3. The manufacturing method according to claim 1, wherein Y in the general formula () is a chlorine atom.