JPH07278047A - Production of aryloxypropionic acid - Google Patents

Abstract

PURPOSE:To obtain a high-purity aryloxypropionic acid useful as a synthetic intermediate for a herbicide, etc., efficiently and in high yield, by reacting a specific alkali (alkaline earth) salt of an aryloxyphenol with a specific alkaline earth salt of an aryloxyphenoxypropionic acid. CONSTITUTION:An alkali (alkaline earth) salt of an aryloxyphenol of formula I (Ar is an aryl) is reacted with an alkaline earth salt of an aryloxyphenoxypropionic acid of formula II (X is a halogen) to give the objective aryloxypropionic acid of formula III. An aryl halide of the formula ArX is reached with hydroquinone in the presence of an alkali (alkaline earth) compound to preferably give the alkali (alkaline earth) salt of an aryloxyphenol of formula I.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing aryloxyphenoxypropionic acid which is highly effective as a herbicide. Aryloxyphenoxypropionic acid is used as an acid itself or an ester of rice weeds for broadleaf crops. Used as a herbicide.

[0002]

2. Description of the Related Art Conventionally, aryloxyphenoxypropionic acid and its ester are generally represented by the following (A):
It is manufactured by methods such as (B) and (C).

[0003]

[Chemical 6]

[0004]

[Chemical 7]

[0005]

[Chemical 8]

(Ar is an aryl group, X is a halogen atom,
R ¹ is a hydrogen atom, a lower alkyl group, R ² is a lower alkyl group, and M is an alkali metal. )

[0007]

The above method (A) is a method for producing a high yield of aryloxyphenoxypropionic acid and its ester, but the yield of 4-hydroxyphenoxypropionic acid and its ester as raw materials is not high. The rate is as low as 75%. The method (B) is a method for producing a high yield of aryloxyphenoxypropionic acid ester, but when an optically active form of 2-halogenopropionic acid ester is used, its racemization is fast and the optical activity of aryloxyphenoxypropionic acid ester is high. It is not suitable as a method for producing an active form.

The method (C) is a production method in which racemization hardly occurs even when an optically active 2-halogenopropionic acid is used, but the conversion of aryloxyphenol is 5%.
The reaction stopped halfway at about 0%, and the yield of aryloxyphenoxypropionic acid was also extremely low. This is because a side reaction occurs in which 2-halogenopropionic acid is further added to the aryloxyphenoxypropionic acid that was once generated.

[0009]

Means for Solving the Problems As a result of intensive studies made by the present inventors to overcome the drawbacks of the above method (C), 2
-Instead of the alkali salt of halogenopropionic acid, 2-
The inventors have found that aryloxyphenoxypropionic acid is quantitatively produced when an alkaline earth salt of halogenopropionic acid is used, and have completed the present invention.

That is, the present invention has the general formula [I]

[0011]

[Chemical 9]

An alkali salt and / or an alkaline earth salt of aryloxyphenol represented by (Ar represents an aryl group) and a general formula [II]

[0013]

[Chemical 10]

The general formula [III] is characterized in that an alkaline earth salt of 2-halogenopropionic acid represented by the formula (X represents a halogen atom) is reacted.

[0015]

[Chemical 11]

The present invention relates to a method for producing aryloxyphenoxypropionic acid represented by: In the above formula, examples of the alkali salt of aryloxyphenol of the general formula [I] include metal salts such as lithium, sodium and potassium. Examples of the alkaline earth salt of the aryloxyphenol of the general formula [I] and the 2-halogenopropionic acid of the general formula [II] include metal salts such as calcium, magnesium and barium.

As the alkaline earth salt of 2-halogenopropionic acid of the general formula [II], a barium metal salt is preferable. As the halogen atom of X, a fluorine atom, a chlorine atom,
Examples thereof include bromine atom and iodine atom, and chlorine atom is preferable. Especially as Ar,

[0018]

[Chemical 12]

(X ₁ and X ₂ represent a hydrogen atom, a halogen atom, a trihalogeno alkyl group having 1 to 5 carbon atoms, or a nitrile group), and the like.

[0020]

[Chemical 13]

A group (X ₁ represents a chlorine atom) is preferred. Examples of X ₁ and X ₂ include a hydrogen atom, a halogen atom, a trihalogeno-substituted alkyl group having 1 to 5 carbon atoms, and a nitrile group. Examples of the trihalogeno-substituted C1-5 alkyl group include a trifluoromethyl group and trifluoro-
n-butyl group, trichloromethyl group, trichloro-n-
Examples thereof include a propyl group, a tribromomethyl group, a tribromo-n-butyl group, a triiodomethyl group, and a triiodo-i-propyl group.

A method for producing the aryloxyphenoxypropionic acid of the general formula [III] will be described below. Alkali salt of aryloxyphenol of the general formula [I] and /
Alternatively, the reaction method of the alkaline earth salt with the alkaline earth salt of 2-halogenopropionic acid of the general formula [II] includes the following methods.

(1) A method of separately preparing and reacting an alkali salt of aryloxyphenol of the general formula [I] and an alkaline earth salt of 2-halogenopropionic acid of the general formula [II]. (2) A method of separately preparing and reacting an alkaline earth salt of aryloxyphenol of the general formula [I] and an alkaline earth salt of 2-halogenopropionic acid of the general formula [II].

(3) A method of reacting an aryloxyphenol of the general formula [I] with a 2-halogenopropionic acid of the general formula [II] in the presence of an alkaline earth compound. Alkali salt of aryloxyphenol of the general formula [I] and /
Alternatively, the amount of the alkaline earth salt of 2-halogenopropionic acid of the general formula [II] used with respect to the alkaline earth salt is usually 1 with respect to the aryloxyphenol of the general formula [I].
To 3 times mol, preferably 1.1 to 1.5 times mol.

The alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] and the general formula [I
The reaction temperature for the preparation of the alkaline earth salt of 2-halogenopropionic acid of [I] and the reaction thereof is usually 20 to 1
The range of 20 ° C, preferably the range of 30 to 100 ° C is good. The alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] and 2- of the general formula [II]
If necessary, an organic solvent may be used in the preparation of the alkaline earth salt of halogenopropionic acid and in these reactions.

Examples of the organic solvent include electron-donating solvents such as dimethylformamide, dimethylsulfoxide and dimethylimidazolidinone, and these may be used in combination. The amount of the organic solvent used is usually 2 to 30 with respect to the aryloxyphenol of the general formula [I].
Good range of parts.

The alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] and the general formula [I
When water is produced in the preparation of the alkaline earth salt of 2-halogenopropionic acid of [I] and these reactions, water may be removed from the product by using a rectification column or the like under normal pressure or reduced pressure. The alkali salt and / or alkaline earth salt of aryloxyphenol of general formula [I] can be prepared from the aryloxyphenol of general formula [I] and an alkaline compound and / or alkaline earth compound.

Examples of the alkali compound include metals such as lithium, sodium and potassium, and metal compounds such as lithium, sodium and potassium. Examples of the metal compound such as lithium, sodium and potassium include alkali hydroxide and alkali hydride. Specific examples of the alkali hydroxide include lithium hydroxide, sodium hydroxide,
Examples include potassium hydroxide and the like.

Specific examples of the alkali hydride include lithium hydride, sodium hydride, potassium hydride and the like. Examples of the alkaline earth compound include metals such as magnesium and metal compounds such as calcium, magnesium and barium. Examples of metal compounds such as calcium, magnesium and barium include alkaline earth hydroxides and alkaline earth hydrides.

Specific examples of the alkaline earth hydroxides include calcium hydroxide, magnesium hydroxide and barium hydroxide. Specific examples of alkaline hydrides include calcium hydride and the like. The amount of the alkali compound used is usually in the range of 1 to 10 times, preferably 1 to 2 times the mol of the aryloxyphenol of the general formula [I].

The amount of the alkaline earth compound used is usually 1 with respect to the aryloxyphenol of the general formula [I].
The range of 10 to 10 equivalents, and preferably the range of 1 to 3 equivalents is preferable. Furthermore, the alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] is represented by the general formula [I
It can also be prepared from an aryl halide of V], hydroquinone, an alkali compound and / or an alkaline earth compound.

In this case, examples of the alkali compound and the alkaline earth compound include the above compounds. The amount of the alkali compound used is usually in the range of 1.8 to 5 times by mole, preferably in the range of 2 to 2.5 times by mole with respect to the aryl halide of the general formula [IV]. The amount of the alkaline earth compound used is usually in the range of 1.8 to 10 times the equivalent amount, preferably 2 to 3 times, with respect to the aryl halide of the general formula [IV].
A range of double equivalents is good.

The amount of hydroquinone used is usually in the range of 1 to 10 times, preferably 1 to 1.5 times the mol of the aryl halide of the general formula [IV]. The alkaline earth salt of 2-halogenopropionic acid of the general formula [II] can be prepared from the 2-halogenopropionic acid of the general formula [II] and an alkaline earth compound. Examples of the alkaline earth compound include the above compounds.

Of these, barium compounds are particularly preferable. The amount of the alkaline earth compound used is represented by the general formula [I
I-] 2-halogenopropionic acid is usually in the range of 1 to 5 times equivalent, preferably 1 to 2 times equivalent. As the 2-halogenopropionic acid of the general formula [II], a racemate and an optically active form can be used.

The alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] and the general formula [II]
The reaction of the alkaline earth salt of 2-halogenopropionic acid with the above formula yields the alkaline earth salt of aryloxyphenoxypropionic acid of the general formula [III]. Therefore, the resulting reaction mixture of the alkaline earth salt of aryloxyphenoxypropionic acid of the general formula [III] is treated with an acid to produce the aryloxyphenoxypropionic acid of the general formula [III].

Examples of the acid include mineral acids such as hydrochloric acid, sulfuric acid, nitric acid and the like, organic acids such as paratoluenesulfonic acid, etc., and they are used as they are or in the form of an aqueous acid solution. As the amount of the acid used, an amount that makes the reaction mixture acidic is used. The temperature of the acid treatment is usually in the range of 0 to 100 ° C. Further, the aryloxyphenoxypropionic acid of the general formula [III] thus obtained can be further purified, if necessary, by means of alkali and acid treatment, recrystallization, chromatography and the like.

The aryloxyphenoxypropionic acid of the general formula [III] obtained by the present invention can be esterified with an alkyl halide, a dialkyl sulfate or the like, if necessary. Even if an optically active form of aryloxyphenoxypropionic acid of the general formula [III] is used, an optically active form of the aryloxyphenoxypropionic acid ester of the general formula [III] can be produced without causing racemization.

[0038]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. Example 1 2.72 g (0.01 mol) of 4- (6-chloro-2-quinoxalyloxy) phenol, 6.3 g (0.02 mol) of barium hydroxide octahydrate and 30 g of dimethylformamide were purified. 70-80 after charging to the flask with distillation column
The reaction was carried out for 1 hour while removing generated water at ℃.

Next, after cooling to 50 to 60 ° C. and adding 1.2 g of L-2-chloropropionic acid, 50 to 6 under reduced pressure.
The reaction was carried out at 0 ° C for 6 hours while removing generated water. When the reaction product was analyzed by high performance liquid chromatography,
The conversion rate of 4- (6-chloro-2-quinoxalyloxy) phenol was 85%. Dimethylformamide was distilled off from the reaction product, 100 ml of diethyl ether and 100 ml of water were added, and then 10 m of a 10 wt% hydrochloric acid aqueous solution was added.
1 was added to separate the aqueous layer, and the diethyl ether layer was added to 10
Washed twice with ml.

After 10 ml of a 10 wt% sodium carbonate aqueous solution was added to the diethyl ether layer to separate the diethyl ether layer, 20 ml of a 10 wt% aqueous hydrochloric acid solution and 100 ml of diethyl ether were added to the aqueous layer. The diethyl ether layer was washed twice with 10 ml of water, dried over anhydrous sodium sulfate, and the diethyl ether was distilled off. As a result, D (+)-2- [4
2.7 g (yield 80%) of-(6-chloro-2-quinoxalyloxy) phenoxy] propionic acid was obtained.

The optical purity of the obtained D (+)-2- [4- (6-chloro-2-quinoxalyloxy) phenoxy] propionic acid was 91% ee. Example 2 2.72 g of 4- (6-chloro-2-quinoxalyloxy) phenol, 3.7 g of barium hydroxide octahydrate and 30 g of dimethylformamide were charged in a flask equipped with a rectification column and then 70-80. The reaction was carried out for 1 hour while removing generated water at ℃.

Then, L-2-chloropropionic acid barium salt (1.2 g of L-2-chloropropionic acid, 1.9 g of barium hydroxide octahydrate) was dissolved in 10 g of water, and dehydrated and dried powder. After adding, the reaction was carried out for 3 hours under reduced pressure at 50 to 60 ° C. while removing generated water. When the reaction product was treated in the same manner as in Example 1, D (+)-2- [4
3.2 g (yield 93%) of-(6-chloro-2-quinoxalyloxy) phenoxy] propionic acid were obtained.

The conversion of 4- (6-chloro-2-quinoxalyloxy) phenol was 100%, and the obtained D
The optical purity of (+)-2- [4- (6-chloro-2-quinoxalyloxy) phenoxy] propionic acid was 91%.
It was ee. Example 3 2.72 g (0.01 mol) of 4- (6-chloro-2-quinoxalyloxy) phenol, calcium hydride 4.
6 g (0.011 mol) and dimethylformamide 30
After charging g to the flask, the mixture was reacted at 70 to 80 ° C. for 1 hour.

Next, after cooling to 50 ° C., 1.2 g of L-2-chloropropionic acid was added and the reaction was carried out for 6 hours. After adding 100 ml of diethyl ether and 100 ml of water to the reaction product, 10 ml of a 10 wt% hydrochloric acid aqueous solution was added to separate the aqueous layer, and the diethyl ether layer was washed twice with 10 ml of water.

20 ml of 10 wt% sodium carbonate aqueous solution was added to the diethyl ether layer to separate the diethyl ether layer, and then 30 ml of 10 wt% aqueous hydrochloric acid solution and 100 ml of diethyl ether were added to the aqueous layer. The diethyl ether layer was washed twice with 10 ml of water, dried over anhydrous sodium sulfate, and the diethyl ether was distilled off. As a result, D (+)-2- [4
3.0 g (yield 87%) of-(6-chloro-2-quinoxalyloxy) phenoxy] propionic acid was obtained.

The optical purity of the obtained D (+)-2- [4- (6-chloro-2-quinoxalyloxy) phenoxy] propionic acid was 92% ee. Example 4 2.72 g of 4- (6-chloro-2-quinoxalyloxy) phenol, 0.42 g of sodium hydroxide and 30 g of dimethylformamide were charged in a flask equipped with a rectification column, and the pressure was reduced while removing generated water. Under the conditions, the reaction was carried out at 40 ° C for 1 hour and further at 70 to 80 ° C for 1 hour.

Then, L-2-chloropropionic acid barium salt (1.2 g of L-2-chloropropionic acid, 1.9 g of barium hydroxide octahydrate) was dissolved in 10 g of water, and dehydrated and dried powder. After adding, the reaction was carried out for 3 hours under reduced pressure at 50 to 60 ° C. while removing generated water. When the reaction product was treated in the same manner as in Example 1, D (+)-2- [4
3.2 g (yield 93%) of-(6-chloro-2-quinoxalyloxy) phenoxy] propionic acid were obtained.

The conversion of 4- (6-chloro-2-quinoxalyloxy) phenol was 100%, and the obtained D
The optical purity of (+)-2- [4- (6-chloro-2-quinoxalyloxy) phenoxy] propionic acid is 86%.
It was ee. Example 5 After charging 2.0 g of 2,6-dichloroquinoxaline, 1.15 g of hydroquinone, 0.84 g of sodium hydroxide and 30 g of dimethylformamide in a flask with a rectification column, under reduced pressure while removing generated water, The reaction was carried out at 40 ° C for 1 hour and then at 80 to 90 ° C for 2 hours.

Next, the mixture was cooled to 50 ° C., and barium L-2-chloropropionate (1.2 g of L-2-chloropropionic acid, 1.9 g of barium hydroxide octahydrate) was added to 10 g of water.
Dissolved in water, dehydrated, dried powder) and added under reduced pressure,
The reaction was carried out at 60 ° C. for 3 hours while removing the produced water. When the reaction product was treated in the same manner as in Example 1, D (+)
-2- [4- (6-chloro-2-quinoxalyloxy)
Phenoxy] propionic acid (3.2 g, yield 93%) was obtained.

The conversion rate of the produced 4- (6-chloro-2-quinoxalyloxy) phenol was 98%, and the obtained D (+)-2- [4- (6-chloro-2-quino) was obtained. The optical purity of quizaryloxy) phenoxy] propionic acid is
It was 86% ee.

[0051]

INDUSTRIAL APPLICABILITY According to the present invention, an aryloxyphenol alkali salt and / or an alkaline earth salt of the general formula [I] and a 2-halogenopropionic acid alkaline earth salt of the general formula [II] are quantitatively and generally used. The aryloxyphenoxypropionic acid of the formula [III] can be produced.

Even if an optically active form of 2-halogenopropionic acid of the general formula [II] is used, an optically active form of aryloxyphenoxypropionic acid of the general formula [III] is produced with almost no racemization. You can The alkali salt and / or alkaline earth salt of aryloxyphenol of the general formula [I] is prepared by reacting an aryl halide of the general formula [IV] with hydroquinone in the presence of an alkaline compound and / or an alkaline earth compound. You can also do it.

Claims (5)

[Claims] 1. A compound represented by the general formula [I]: (Ar represents an aryl group) and an alkali salt and / or alkaline earth salt of aryloxyphenol represented by the general formula [II] (X represents a halogen atom) represented by the general formula [III] ## STR00003 ## characterized by reacting an alkaline earth salt of 2-halogenopropionic acid. A method for producing aryloxyphenoxypropionic acid represented by: 2. An aryl halide and hydroquinone represented by the general formula [IV] ArX [IV] (Ar represents an aryl group and X represents a halogen atom) in the presence of an alkali compound and / or an alkaline earth compound. The aryloxyphenoxypropionic acid represented by the general formula [III] according to claim 1, which is an alkali salt and / or an alkaline earth salt of aryloxyphenol represented by the general formula [I]. Manufacturing method. 3. Ar is represented by: (X ₁ and X ₂ represent a hydrogen atom, a halogen atom, a trihalogeno alkyl group having 1 to 5 carbon atoms, or a nitrile group.) A group represented by the general formula [III] according to claim 1 or 2, wherein ] The manufacturing method of aryloxy phenoxy propionic acid represented by these. 4. X is a chlorine atom and Ar is (X ₁ represents a chlorine atom) group, The method for producing an aryloxyphenoxypropionic acid represented by the general formula [III] according to claim 1. 5. The aryloxyphenoxypropione represented by the general formula [III] according to claim 1, wherein the 2-halogenopropionic acid represented by the general formula [II] is an optically active substance. Acid manufacturing method.