JP2555172B2 - Method for separating 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a compound of formula (II) [In the formula (II), R is a lower alkyl group or a hydrogen atom, X ₁ and X ₂ are each a hydrogen atom or a fluorine atom, and Y ₁ and Y ₂ are a hydrogen atom, a chlorine atom or a bromine atom. ] 3-phenoxybenzyl 2- (4-
The present invention relates to a method for separating alkoxyphenyl) -2-methylpropyl ethers (hereinafter abbreviated as benzylmethylpropyl ethers).

More specifically, formula (I) [In the formula (I), R, X ₁ , X ₂ , Y ₁ and Y ₂ are each represented by the above formula (I
It has the same meaning as R, X ₁ , X ₂ , Y ₁ and Y _{2 in} I). ]
3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ether] and the like (hereinafter abbreviated as benzylmethylethyl ethers) represented by the above formula (II The present invention provides a method for efficiently separating the compound of formula (II) from the benzylmethylpropyl ethers of (1).

It is known that the benzyl methyl propyl ether derivative represented by the general formula (II) is a compound having low fish toxicity and excellent insecticidal and acaricidal activity.

However, with regard to agricultural chemicals, not only active ingredients but also environmental pollution due to impurities contained have become a problem,
It is desired to reduce the contamination of raw materials and impurities caused by the reaction as much as possible.

[Problems to be Solved by Conventional Techniques and Inventions]

Conventionally, formula (II) [In the formula (II), R, X ₁ , X ₂ , Y ₁ and Y ₂ are each represented by the above formula (I
It has the same meaning as I). ] The method for producing 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers represented by the following formula is disclosed in JP-B-62-10493. For example, in the method described in the publication,
3-Chloro-4-ethoxyneophyl chloride and 3-phenoxybenzyl alcohol are reacted in the presence of a base in an aprotic polar solvent to give the desired condensed compound 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl). ) -2-Methylpropyl ether was obtained, but at the same time, an isomer, 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether, was also produced in a non-negligible amount. ing.

The benzyl dimethyl ethyl ethers represented by the formula (I) which are the isomers and the formula (I
Regarding the separation of benzyl methyl propyl ethers represented by I), in the publication, low boiling components such as unreacted 3-phenoxybenzyl alcohol are distilled off, and then high boiling components including a target product are removed. The obtained product is further crystallized to obtain a purified product of the target compound, benzyl methyl propyl ether, or the reaction crude product is purified by column chromatography to obtain benzyl methyl propyl ether.

However, the target compound is represented by the 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ether represented by the formula (II) and the isomer of the compound represented by the formula (I). The 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers are, as is clear from their structure,
The physical and chemical properties are very similar, and in a usual purification operation such as distillation, recrystallization, crystallization, or column chromatography from the mixture of the compounds of formula (I) and formula (II), It is difficult to efficiently separate the benzylmethylpropyl ethers represented by the above formula (II).

The present invention provides 3-phenoxybenzyl 2 represented by the formula (II) containing as an impurity 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers of the formula (I) which are isomers. It is intended to efficiently separate the benzylmethylpropyl ethers from the-(4-alkoxyphenyl) -2-methylpropyl ethers.

[Means for solving the problem]

The present inventors have found that 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ether represented by the above formula (II) and the above formula (I) which is an isomer thereof.
By selectively changing the isomer benzyldimethylethyl ethers from a mixture of 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers represented by The inventors have earnestly studied a method for efficiently separating the target compound, benzyldimethylethylpropyl ethers of the formula (II).

As a result, by treating the mixture with an acid such as sulfuric acid or hydrochloric acid, the benzyldimethylethyl ethers of the formula (I) are selectively ether-cleaved, and the ether-cleaved compound of the formula (I) is also used. Is, for example, the reaction formula (II
It was found that the compound changed to a compound having a relatively low boiling point as shown in I).

It was also found that the benzylmethylpropyl ethers represented by the formula (II) exist stably under these conditions. The present invention has been made based on these findings.

That is, the present invention has the formula (I) [In the formula (I), R is a lower alkyl group or a hydrogen atom, X ₁ and X ₂ are each a hydrogen atom or a fluorine atom, and Y ₁ and Y ₂ are a hydrogen atom, a chlorine atom, or a bromine atom. is there. ] The formula (II) containing 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers represented by In formula (II), R, X ₁ , X ₂ , Y ₁ and Y ₂ are R of formula (I),
Same as X ₁ , X ₂ , Y ₁ and Y ₂ . ] From 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers represented by
In the method for separating benzylmethylpropyl ethers of the formula (II), represented by the above general formula (II), which is characterized in that the treatment is carried out with a protic acid having an acid dissociation index pka value in the aqueous solution of less than 2.2. 3-phenoxybenzyl 2-
A method for separating (4-alkoxyphenyl) -2-methylpropyl ethers.

According to the method of the present invention, a protic acid is added to a mixture of isomers of benzyl methyl ethyl ethers and benzyl methyl propyl ethers and reacted to give benzyl dimethyl ethyl ethers of the above formula (I). Is decomposed into a component having completely different properties chemically and physically from the benzylmethylpropyl ether represented by the formula (II), so that the benzylmethylpropyl ether can be advantageously separated. During the reaction, the separation of the target compound benzylmethylpropyl ether can also be suppressed, and the target compound benzylmethylpropyl ether of the formula (II) can be obtained in high yield and high purity.

 The general embodiments of the present invention are as follows.

The dimethyl ethyl benzyl ethers represented by the above formula (I) and the methyl propyl benzyl ethers represented by the above formula (II), which are raw materials used in the method of the present invention, are the compounds described in
According to the method described in JP-10493, β, β-dimethylphenethyl chlorides or α, α-dimethylphenethyl chlorides and 3-phenoxybenzyl alcohol are easily reacted in the presence of a base in an aprotic polar solvent. It is possible.

0.001-5 relative to 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers of the above formula (I) contained as impurities in the benzylmethylpropyl ethers of the above formula (II) Protonic acid or an aqueous solution thereof is charged into the reactor so that the molar ratio is 0.05 to 3 times. There is no particular limitation on the permissible amount of the benzyl dimethyl ethyl ether represented by the formula (I), and any amount of benzyl dimethyl ethyl ether does not affect the method of the present invention.

As the protic acid used in the present invention, a protic acid having an acid dissociation index pka value in an aqueous solution of less than 2.2 is used. With a protic acid having a pka value of more than 2.2, the decomposition of ethers becomes extremely slow, which is not preferable. In particular,
Examples thereof include inorganic acids such as sulfuric acid, hydrochloric acid, hydrobromic acid, nitric acid or phosphoric acid, or organic acids such as aromatic or aliphatic sulfonic acids, trifluoroacetic acid, trichloroacetic acid or dichloroacetic acid. It is not limited to protic acids.

Further, the above-mentioned protic acid is usually used alone, but there is no problem even if two or more kinds of acids are used in combination. Further, these protic acids can be used either in the form of the acid itself or in the form of an aqueous solution, but when used in an aqueous solution, the concentration of the protic acid contained in the aqueous solution is preferably 10% by weight or more. If the concentration is less than 10% by weight, the reaction rate becomes extremely slow, which is not practical.

Regarding the amount of the protic acid used, it may induce decomposition and side reactions of the benzylmethylpropyl ethers of the formula (II), and therefore the benzyldimethylethyl ethers of the formula (I) contained as impurities are included. On the other hand, it is preferable to use it in an amount of 5 mol times or less. Also, the lower limit of the amount used is 0.001 mol times (to benzyl dimethyl ethyl ethers), and below this, the reaction rate is extremely slow,
It is hard to say that it is a practical method.

Furthermore, in order to carry out the reaction more smoothly, when a protonic acid aqueous solution or the like is used, a phase transfer catalyst such as triethylbenzylammonium chloride may be added.

In the present invention, the reaction temperature and reaction time of the acid treatment are
50 to 200 ° C., 0.5 to 20 hours, preferably 60 to 15
0 ° C., 1 to 12 hours. When the reaction temperature is lower than 50 ° C, the reaction rate tends to be slow, and conversely, when the temperature is 200
If the temperature is higher than 0 ° C, the yield of the target compound benzylmethylpropyl ether of the formula (II) tends to be degraded due to decomposition and side reactions. When performing acid treatment,
No solvent may be used, or a solvent may be used.

Examples of the solvent used include benzene, toluene,
Aprotic non-polar solvent such as chloroform, N, N'-dimethylethylene urea, dimethyl sulfoxide, N, N-
Examples include aprotic polar solvents such as dimethylformamide, and protic polar solvents such as ethanol and acetic acid. These may be used alone or in combination of two or more.

Furthermore, the order of charging when carrying out the reaction is as shown in the above formula (I).
Of the above formula (I containing benzyldimethylethyl ethers of
A method in which the benzyl methylpropyl ethers of I) and the protonic acid may be charged at once, and either the benzylmethylpropyl ethers or the protonic acid is heated to a predetermined reaction temperature and then added. But it doesn't matter.

In the present invention, when hydrohalic acid is used as the protonic acid, the benzyl dimethyl ethers represented by the above formula (I) produce ether cleavage products such as those represented by the reaction formula (IV).

Further, when a protic acid other than hydrohalic acid is used, an ether cleavage product as shown in reaction formula (V) is produced.

After the acid treatment reaction, the target compound benzylmethylpropyl ether of the formula (II) can be isolated by washing the acid treatment solution with water until it becomes neutral, or adding an alkaline aqueous solution, etc. After removing the protic acid used in the reaction, the benzyl methyl propyl ether, which is the target compound, can be obtained by subjecting it to a separation operation such as distillation, recrystallization, crystallization, or column chromatography. can get.

The present invention thus provides 3-phenoxybenzyl 2
-(3-chloro-4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (3,5
-Dichloro-4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (3-bromo-4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- (3
-Chloro-4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2
-(3,5-Dichloro-4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- (3-bromo-4-methoxyphenyl)-
2-Methylpropyl ether, 3- (4-fluorophenoxy) benzyl 2- (3-chloro-4-methoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) benzyl 2- (3,5- Dichloro-4-
Methoxyphenyl) -2-methylpropyl ether, 3
-(4-Fluorophenoxy) benzyl 2- (3-bromo-4-methoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) -4-fluorobenzyl 2- (3-chloro-4-methoxy) Phenyl)-
2-methylpropyl ether, 3- (4-fluorophenoxy) 4-fluorobenzyl 2- (3,5-dichloro-
4-methoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) -4-fluorobenzyl 2- (3-bromo-4-methoxyphenyl) -2
-Methylpropyl ether, 3-phenoxybenzyl 2
-(3-chloro-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (3,5
-Dichloro-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl-2- (3-bromo-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2-
(3-Chloro-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- (3,5-dichloro-4-ethoxyphenyl) -2
-Methylpropyl ether, 3- (4-fluorophenoxy) benzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) benzyl 2- (3,5-dichloro -4-ethoxyphenyl) -2-methylpropyl ether, 3-
(4-Fluorophenoxy) benzyl 2- (3-bromo-4-ethoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) -4-fluorobenzyl 2- (3-chloro-4-ethoxyphenyl) ) -2
-Methylpropyl ether, 3- (4-fluorophenoxy) -4-fluorobenzyl 2- (3,5-dichloro-
4-ethoxyphenyl) -2-methylpropyl ether, 3- (4-fluorophenoxy) -4-fluorobenzyl 2- (3-bromo-4-ethoxyphenyl) -2
-Methylpropyl ether, 3-phenoxy-6-fluorobenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxy-
6-Fluorobenzyl 2- (3,5-dichloro-4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxy-6-fluorobenzyl 2- (3-bromo-4)
-Ethoxyphenyl) -2-methylpropyl ether,
3- (2-Fluorophenoxy) benzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether, 3- (2-fluorophenoxy) benzyl 2-
(3,5-dichloro-4-ethoxyphenyl) -2-methylpropyl ether, 3- (2-fluorophenoxy)
Benzyl 2- (3-bromo-4-ethoxyphenyl)-
2-Methylpropyl ether, 3-phenoxybenzyl 2- [3-chloro-4- (i-propoxy) phenyl]
2-Methylpropyl ether, 3-phenoxybenzyl 2- [3,5-dichloro-4- (i-propoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3-bromo-4- ( i-propoxy) phenyl] -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- [3-chloro-4- (i
-Propoxy) phenyl] -2-methylpropyl cyther, 3-phenoxy-4-fluorobenzyl 2- [3,
5-dichloro-4- (i-propoxy) phenyl] -2
-Methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- [3-bromo-4- (i-propoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3-chloro-4- ( 1-methylpropoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3,5-dichloro-4
-(1-Methylpropoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3-bromo-4- (1-methylpropoxy) phenyl] 2-methylpropyl ether, 3-phenoxybenzyl 2-
[3-chloro-4- (n-butoxy) phenyl] -2-
Methyl propyl ether, 3-phenoxybenzyl 2-
[3,5-dichloro-4- (n-butoxy) phenyl]-
2-Methylpropyl ether, 3-phenoxybenzyl 2- [3-bromo-4- (n-butoxy) phenyl]-
2-Methylpropyl ether, 3-phenoxybenzyl 2- [3-chloro-4- (t-butoxy) phenyl]-
2-Methylpropyl ether, 3-phenoxybenzyl 2- [3,5-dichloro-4- (t-butoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3-bromo-4- (t -Butoxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3-chloro-4- (n-pentyloxy)
Phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- [3,5-dichloro-4- (n-pentyloxy) phenyl] -2-methylpropyl ether,
3-phenoxybenzyl 2- [3-bromo-4- (n-
Pentyloxy) phenyl] -2-methylpropyl ether, 3-phenoxybenzyl 2- (4-ethoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl-4-fluorobenzyl 2- (4-ethoxyphenyl) -2 -Methylpropyl ether, 3-phenoxybenzyl 2- (4-methoxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (3-
Chloro-4-hydroxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (3,5-dichloro-4-hydroxyphenyl) -2-methylpropyl ether, 3-phenoxybenzyl 2- (4-hydroxyphenyl) ) -2-Methylpropyl ether, 3-phenoxybenzyl 2- (3-bromo-4-hydroxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- (3-chloro-4-hydroxyphenyl) ) -2-Methylpropyl ether, 3-
Phenoxy-4-fluorobenzyl 2- (3-bromo-
4-hydroxyphenyl) -2-methylpropyl ether, 3-phenoxy-4-fluorobenzyl 2- (4-
Hydroxyphenyl) -2-methylpropyl ether,
It can be applied to separation methods such as.

〔Example〕

Next, the present invention will be described more specifically by showing Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 75%, 3
A mixed solution 410.9 containing 25% of -phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether was placed in a 14-necked flask, and the temperature was raised to 120 ° C with stirring. 50% sulfuric acid (49.0 g) [3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether in an equimolar amount as SO ₄ ^2- amount] was added for 1 hour. In short, the solution was dropped and charged at the same temperature. The mixture was kept warm at the same temperature for 5 hours while stirring.

After completion of the reaction, the reaction solution was cooled to room temperature and discharged into water (1). The separated lower organic layer was washed with 500 ml of water three times, and after separation, heating was performed under reduced pressure to dehydrate the oil 403.
2 g were obtained.

The results of gas chromatography analysis by the internal standard method were as follows.

-3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 75.6%
(Residual rate 98.8%) 3-Phenoxybenzyl alcohol 11.5% 3-Chloro-4-ethoxyisobutenylbenzel 12.8
% 3-Phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether Trace 400 g of the oily substance obtained as described above was placed in a distillation flask and the pressure was reduced under a nitrogen atmosphere. Distillation was performed. The removal by distillation under reduced pressure was started by raising the temperature from room temperature under a reduced pressure of 1 mmHg and raising the temperature of the distillation pot to 160 ° C. to distill off low-boiling substances.

The distillate was 96.5 g and the residue in the kettle was 301.2 g. The gas chromatographic analysis of the residue in the kettle by the internal standard method was as follows.

-3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 99.6%
(Residual rate 98.9%) ・ 3-phenoxybenzyl alcohol 0.2% ・ 3-Chloro-4-ethoxyisobutenylbenzene traces ・ 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethyl Ethyl ether trace Example-2 3-phenoxy 2- (4-ethoxyphenyl) -2-
Methyl propyl ether 95%, 3-phenoxy 2- (4
-Ethoxyphenyl) -1,1-dimethylethyl ether (56.5%) was added to a 500 ml four-necked flask containing 376.5% g, and a 20% hydrochloric acid aqueous solution (0.5 g) [3-phenoxy 2
- (4-ethoxyphenyl) -1,1-dimethyl-ethyl ether to Cl ^- 0.05 times the molar amount as the amount] was added, 100
The temperature was raised to 0 ° C., and the mixture was heated and stirred at the same temperature for 10 hours.

After the reaction was completed, 100 ml of 3% NaOH aqueous solution was added for washing, the lower organic layer was separated, washed with 300 ml of water three times, and after liquid separation, the lower organic layer was dehydrated under reduced pressure. The analysis results of gas chromatography by the internal standard analysis method, which gave 375.3 g of an oily matter, were as follows.

-3-phenoxybenzyl 2- (4-ethoxyphenyl) -2-methylpropyl ether 94.4% (residual rate 98.9
%) 3-phenoxybenzyl chloride 2.5% 3-phenoxybenzyl alcohol traces 3-ethoxy-isobutenylbenzene 2.8% 3-phenoxy 2- (4-ethoxyphenyl) -1,1
-Dimethylethyl ether Trace Example-3 3-phenoxybenzyl 2- (3,5-dichloro-4-
Hydroxyphenyl) -2-methylpropyl ether 50
%, 3-phenoxybenzyl 2- (3,5-dichloro-4
-Hydroxyphenyl-1,1-dimethyl ethyl ether 5
382.9 g of a mixed solution containing 0% was charged into a 4-necked flask of 1 and heated to 150 ° C. with stirring. This requires 40.9 g of trichloroacetic acid [0.5 mol times amount of 3-phenoxybenzyl 2- (3,5-dichloro-4-hydroxyphenyl-1,1-dimethylethyl ether as CCl ₃ COO ⁻ ]] for 1 hour. Then, the mixture was added dropwise, and the mixture was heated and stirred at the same temperature for 12 hours.

After completion of the reaction, the reaction solution was cooled to room temperature and discharged into water 1. The organic layer was separated, washed with water (1) three times, and then dehydrated under reduced pressure to obtain 379.8 g of an oily substance. The results of gas chromatography by the internal standard analysis method are as follows.

-3-phenoxybenzyl 2- (3,5-dichloro-4-
Hydroxyphenyl) -2-methylpropyl ether 5
0.2% (residual rate 99.6%) 3-phenoxybenzyl 2- (3,5-dichloro-4-
Hydroxyphenyl) -1,1-dimethylethyl ether
Traces 3-phenoxybenzyl alcohol 25.8% 3,5-dichloro-4-hydroxy-isobutenylbenzene 21.6% The oil 370 g thus obtained was charged into a distillation flask and the distillation of Example-1 was performed. The low-boiling substance was distilled off under the same conditions.

 The distillate fraction was 175.0 g, and the kettle residue was 185 g.

Gas chromatographic analysis was performed on the residue of the kettle using an internal standard. The results were as follows.

-3-phenoxybenzyl 2- (3,5-dichloro-4-
Hydroxyphenyl) -2-methylpropyl ether 9
9.5% (separation yield 99.1%)-3-phenoxybenzyl alcohol 0.2% -3,5-dichloro-4-hydroxyisobutenylbenzene Traces Example-4 Obtained by acid treatment in the same manner as in Example-1. Oil 140g
[Compositional analysis value (gas chromatography, internal standard method)] 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 75.6% 3-phenoxybenzyl alcohol 11.5% 3- Chloro-4-ethoxyisobutenylbenzene 12.8
% Was placed in a 1-cylindrical separable flask equipped with a baffle, and then 560 g of methanol was added. The mixture was vigorously stirred at 0 ° C. for 5 hours, the crystals that had crystallized were separated by filtration, and the crystals were washed with cold methanol. The crystals were dried under reduced pressure and then dried. The yield was 98.4 g, and the results of gas chromatography analysis were as follows.

-3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 99.4%
(Separation yield 92.4%) ・ 3-phenoxybenzyl alcohol 0.2% ・ 3-chloro-4-ethoxyisobutenylbenzene 0.1
% -Phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether Trace Comparative Example-1 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2- Methyl propyl ether 75%, 3
400 g of a mixed solution containing 25% of -phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether was placed in a distillation flask, and vacuum distillation was performed under N ₂ atmosphere. The vacuum distillation conditions were such that the temperature started to rise from room temperature under a reduced pressure of 0.1 mmHg, and ended when the distillation pot temperature reached 230 ° C.

Distillate 173.5 g Bottom residue 224.7 g Distillation part, bottom residue gas chromatographic analysis by internal standard method was as follows.

Distillate 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 67.7% 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1- Dimethyl ethyl ether 32.2% Residue in kettle 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 80.6%
(Separation yield 60.4%) 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether 19.2% Comparative example-2 3-phenoxybenzyl 2- (3-chloro-4) -Ethoxyphenyl) -2-methylpropyl ether 75%, 3-
140 g of a mixed solution containing 25% of phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether was placed in a 1-cylindrical separable flask equipped with a baffle, and then 540 g of methanol was added. It was The mixture was vigorously stirred at 0 ° C. for 5 hours, the crystals that had crystallized were separated by filtration, and the crystals were washed with cold methanol. The crystals were removed from methanol under reduced pressure and dried. The yield was 104.7 g, and the results of gas chromatography analysis were as follows.

-3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -2-methylpropyl ether 90.5%
(Separation yield 90.2%) 3-phenoxybenzyl 2- (3-chloro-4-ethoxyphenyl) -1,1-dimethylethyl ether 9.3% [Effect of the invention] By implementing the present invention, In addition, 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers can be obtained with high purity.

Claims (4)

(57) [Claims] 1. A formula (I) [In the formula (I), R is a lower alkyl group or a hydrogen atom, X ₁ and X ₂ are each a hydrogen atom or a fluorine atom, and Y ₁ and Y ₂ are a hydrogen atom, a chlorine atom, or a bromine atom. Is. ] 3-phenoxybenzyl 2- (4-alkoxyphenyl) -1,1-dimethylethyl ethers represented by the formula (II) [In the formula (II), R is a lower alkyl group or a hydrogen atom, X ₁ and X ₂ are each a hydrogen atom or a fluorine atom, and Y ₁ and Y ₂ are a hydrogen atom, a chlorine atom, or a bromine atom. Is. ] When the compound of formula (II) is separated from the mixture of 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers represented by the formula, the mixture is treated with an acid dissociation index pKa value in an aqueous solution. Is treated with a protonic acid smaller than 2.2, a method for separating 3-phenoxybenzyl 2- (4-alkoxyphenyl) -2-methylpropyl ethers. 2. The protic acid is sulfuric acid, hydrohalic acid,
The method according to claim 1, which is nitric acid or phosphoric acid. 3. The method according to claim 1, wherein the protonic acid is an aromatic or aliphatic sulfonic acid, trifluoroacetic acid, trichloroacetic acid, or dichloroacetic acid. 4. The method according to claim 1, wherein the reaction temperature of the acid treatment is 50 to 200 ° C.