JP2002308822A - Method for producing phenylenedioxydiacetic acids - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of producing phenylenedioxydiacetic acids represented by formula I (wherein R is a halogen atom, a carboxy group or a 1-4 hydrocarbon group and n is an integer of 0-4) containing no coloring component. SOLUTION: A mixture of dihydroxybenzenes represented by formula (2) and water is mixed with an alkali compound at an initial temperature of 40 deg.C or lower and, subsequently, a halogenated acetic acid is reacted. The mixture of dihydroxybenzenes and water is mixed with the alkali compound in an atmosphere of an oxygen partial pressure of 0.007 MPa or less and the halogenated acetic acid is subsequently reacted. The mixture of dihydroxybenzenes and water is obtained by mixing dihydroxybenzenes with water containing dissolved oxygen in a concentration of 4 ppm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing phenylenedioxydiacetic acids.

[0002]

2. Description of the Related Art The general formula (I) (In the formula, R represents a halogen atom, a carboxyl group, or a hydrocarbon group having 1 to 4 carbon atoms, and n represents an integer of 0 to 4.) The phenylenedioxydiacetic acids represented by It is a compound useful as a raw material for.

[0003] As a method for producing such phenylenedioxydiacetic acids, Japanese Patent Application Laid-Open Nos.
No. 173765 discloses a compound represented by the general formula (II): (Wherein, R represents a halogen atom, a carboxyl group, or a hydrocarbon group having 1 to 4 carbon atoms, and n represents an integer of 0 to 4). After that, a method of reacting with a halogenated acetic acid is disclosed. These publications state that a mixture of dihydroxybenzenes and water is mixed with an alkali compound at 50 ° C. and then reacted with the halogenated acetic acid. Have been. The desired phenylenedioxydiacetic acids can be obtained as free acid crystals by mixing the reaction mixture after the reaction with the halogenated acetic acids with an acid.

However, there is a problem that the phenylenedioxydiacetic acids obtained by the conventional production method contain a coloring component. Such coloring components are components that are not easily removed by a method such as recrystallization.

[0005] As a method for producing phenylenedioxydiacetic acids having a small coloring component, Japanese Patent Application Laid-Open No. 4-173664 discloses a reaction mixture after reaction with halogenated acetic acids in a mineral acid aqueous solution at 80 ° C or higher. There is disclosed a method of obtaining crystals of the free acid of phenylenedioxydiacetic acids by feeding, but it is said that such a method limits the material of the reaction apparatus because a mineral acid aqueous solution of 80 ° C. or higher is used. There was a problem.

Japanese Patent Application Laid-Open No. 4-173765 discloses a method in which a mixture of dihydroxybenzenes and water is mixed with an alkali compound and then reacted with a halogenated acetic acid in the presence of an antioxidant. However, in such a method, there is a concern that an antioxidant is mixed into the obtained phenylenedioxydiacetic acids.

[0007]

SUMMARY OF THE INVENTION The present inventor has proposed the following:
Even without using mineral acid aqueous solution or antioxidant above 0 ° C,
As a result of intensive studies to develop a method capable of producing phenylenedioxydiacetic acids having a small number of coloring components, by setting the initial temperature at which a mixture of dihydroxybenzenes and water is mixed with an alkali compound to 40 ° C. or less, The present inventors have found that phenylenedioxydiacetic acids containing a small amount of a coloring component can be produced, and have reached the present invention.

[0008]

That is, the present invention provides a method of mixing a mixture of dihydroxybenzenes and water represented by the above general formula (II) with an alkali compound at an initial temperature of 40 ° C. or lower, and then forming a halogenated acetic acid. It is intended to provide a method for producing a phenylenedioxydiacetic acid represented by the general formula (I), which is characterized by reacting.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the dihydroxybenzenes represented by the general formula (II), which are raw materials for the production method of the present invention, R represents a halogen atom, a carboxyl group or a C 1 -C 1.
The halogen atoms include, for example, a fluorine atom, a chlorine atom, and a bromine atom. The carboxyl group may form a salt by its hydrogen atom being ionized. Examples of the hydrocarbon group include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, and a t-butyl group. n is an integer of 0 to 4, preferably 0. When n is 2 or more, Rs may be the same or different from each other.

The dihydroxybenzenes represented by the general formula (II) include, for example, resorcin, catechol, hydroquinone, 2-chloro-benzene-1,3-
Diols, 4-chloro-benzene-1,3-diol,
5-chloro-benzene-1,3-diol, 3-chloro-benzene-1,2-diol, 4-chloro-benzene-1,2-diol, 2-chloro-benzene-1,4-diol
Diols, 4,5-dichloro-benzene-1,3-diol, 2,4-dichloro-benzene-1,3-diol, 2,3-dichloro-benzene-1,4-diol,
4,5,6-trichloro-benzene-1,3-diol, 2-methyl-benzene-1,3-diol, 4-methyl-benzene-1,3-diol, 5-methyl-benzene-1,3-diol Diol, 3-methyl-benzene-1,
2-diol, 4-methyl-benzene-1,2-diol, 2-methyl-benzene-1,4-diol, 4,5
-Dimethyl-benzene-1,3-diol, 2,4-dimethyl-benzene-1,3-diol, 4-chloro-5
-Methyl-benzene-1,3-diol, 2-chloro-
3-methyl-benzene-1,4-diol and the like.

A mixture of dihydroxybenzenes and water can be obtained, for example, by mixing dihydroxybenzenes and water. The amount of water used is usually 0.5 times or more and 3 times or less the weight of dihydroxybenzenes. In such a mixture, dihydroxybenzenes are usually dissolved in water to form an aqueous solution of dihydroxybenzenes.

The mixture of dihydroxybenzenes and water is preferably obtained by mixing dihydroxybenzenes with water having a dissolved oxygen of 4 ppm or less. In order to reduce the dissolved oxygen of water to 4 ppm or less, water may be bubbled with an inert gas such as nitrogen gas or Ar gas. After introducing water into the reaction vessel, the pressure inside the vessel may be reduced, and then an inert gas may be introduced.

Examples of the alkali compound include hydroxides and carbonates of alkali metals such as sodium and potassium. Of these, sodium hydroxide and potassium hydroxide are preferably used. The amount of the alkali compound to be mixed with the mixture of dihydroxybenzenes and water is selected so that the pH of the mixture after mixing is generally 7.5 or more and 12 or less, preferably 8.5 or less. 0.1 mol times or more with respect to 1
The molar ratio is at most 0.2 times, preferably at least 0.2 and at most 0.4 times.

An alkali compound mixed with a mixture of dihydroxybenzenes and water is usually used as an aqueous solution thereof, and the concentration of the alkali compound in such an aqueous solution is usually from 5% by weight to 50% by weight.

In the production method of the present invention, the initial temperature at which the mixture of dihydroxybenzenes and water is mixed with the alkali compound is 40 ° C. or lower, preferably 30 ° C. or less.
It is below ° C. When the mixing is started at a temperature exceeding 40 ° C., the coloring components contained in the obtained phenylenedioxydiacetic acids increase. The lower limit of the initial temperature is not particularly limited, and may be a temperature at which a mixture of dihydroxybenzenes and water does not freeze, for example, a temperature of 0 ° C. or higher. The pH of the mixture after mixing is usually 7.5 or more and 12 or less,
Preferably it is 8.5 or less.

The mixture of the mixture of dihydroxybenzenes and water with the alkali compound may be any one as long as the temperature at which mixing is started is 40 ° C. or less. After the mixing is started, the temperature may rise due to heat generation, but in the production method of the present invention, the initial temperature of the mixing may be 40 ° C or less, and the temperature may exceed 40 ° C after the mixing is started. There may be.

After mixing, halogenated acetic acids are reacted. Examples of the halogenated acetic acid include monohalogenated acetic acids such as monochloroacetic acid and monobromoacetic acid. The amount of the used halogenated acetic acid is usually 2 to 4 mol times, preferably 2.2 mol times or less with respect to dihydroxybenzenes. Not less than 3 times and not more than 3 times.

In order to react the halogenated acetic acids, for example, a mixture of dihydroxybenzenes and water after mixing the alkali compounds may be mixed with the halogenated acetic acids, and more specifically, after mixing the alkali compounds. Halogenated acetic acids may be added to a mixture of dihydroxybenzenes and water. Halogenated acetic acids are usually used as an aqueous solution thereof. The mixture of dihydroxybenzenes and water and the halogenated acetic acid are usually mixed while adjusting the pH in the system to 7.5 or more and 12 or less, preferably 8.5 or less. If the pH in the system is less than 7.5, the amount of by-products tends to increase. If the pH in the system exceeds 12, the halogenated acetic acids tend to hydrolyze, so that the pH is preferably 8.5 or less. In order to adjust the pH in the system to the above range, for example, an alkali compound may be added together with the halogenated acetic acid, and the alkali compound is usually added as an aqueous solution thereof at the same time as the halogenated acetic acid. The reaction temperature is usually from 80 ° C to 110 ° C, preferably from 90 ° C to 100 ° C. The reaction may be carried out after addition of the halogenated acetic acids and until the halogenated acetic acids disappear, and the reaction time is usually about 1 to 10 hours.

In the production method of the present invention, an oxygen partial pressure of 0.00
Mixing a mixture of dihydroxybenzenes and water with an alkali compound in an atmosphere of 7 MPa or less, more preferably 0.005 MPa or less, and ideally, an oxygen partial pressure of 0, makes it possible to mix phenylenedioxydioxy with less coloring components. It is preferable in that acetic acids can be obtained.

In order to reduce the oxygen partial pressure to 0.0007 MPa or less, for example, a mixture of dihydroxybenzenes and water and an alkali compound may be mixed under an inert gas stream or an inert gas atmosphere. In order to make the inside of the system under an inert gas atmosphere, for example, an inert gas may be introduced after the inside of the system is depressurized to replace the inside of the system with an inert gas, or the system may be inert at a pressure higher than atmospheric pressure. After introducing the gas, the gas may be exhausted to atmospheric pressure. Examples of the inert gas include a nitrogen gas and an Ar gas.

After the mixing, the halogenated acetic acid is similarly reacted in an atmosphere having an oxygen partial pressure of 0.007 MPa or less, more preferably 0.005 MPa or less, and ideally an oxygen partial pressure of 0. It is preferable to react them under the inert gas stream or the inert gas atmosphere in the same manner as described above.

A mixture of dihydroxybenzenes and water, an aqueous solution of an alkali compound, and an aqueous solution of a halogenated acetic acid used in the reaction may be used after the dissolved oxygen is reduced by a usual method such as a method of bubbling nitrogen gas. Good.

Thus, the desired phenylenedioxydiacetic acids can be obtained by reacting the resulting reaction mixture with an acid after the halogenated acetic acids are reacted. As the acid, for example, a mineral acid such as hydrogen chloride, nitric acid, sulfuric acid and phosphoric acid is used. The amount of the acid used is appropriately selected so that the mixture after being mixed with the mixture of the phenylenedioxydiacetic acids and the aqueous alkali solution has an acidity, for example, usually pH 6 or lower, preferably pH 5 or lower. It is about 2.6 to 3.4 times the phenylenedioxydiacetic acid in terms of the ionizable hydrogen atom of phenylenedioxydiacetic acid. 1. When a monobasic acid is used.
About 6 to 3.4 mole times, about 1.3 to 1.7 mole times when a dibasic acid such as sulfuric acid is used as the acid, and 0 when using a tribasic acid such as phosphoric acid as the acid. It is about 0.8 to 1.1 mole times. The acid is usually used as an aqueous solution, and the content of the acid is usually about 5 to 20 parts by weight per 100 parts by weight of the aqueous solution of the acid.

To mix the reaction mixture with the acid, the acid may be added to the reaction mixture, the reaction mixture may be added to the acid, or the reaction mixture and the acid may be added to the same container.
The reaction mixture and the acid usually have a boiling point of from 0 ° C. to
The mixture is mixed at a temperature of 0 ° C. or lower. When the reaction mixture is added to an acid and mixed, or when the reaction mixture and the acid are added to a container and mixed, at least 1/10, preferably all of the reaction mixture is mixed. May be mixed with an acid at a temperature of 50 ° C. or lower, preferably 0 ° C. or higher.

Thereafter, the mixture of the reaction mixture and the acid is heated at a temperature of usually from 80 ° C. to 110 ° C., preferably from 85 ° C. to 95 ° C.
Keep in the following temperature range. If the temperature is lower than 80 ° C., the purity of the phenylenedioxydiacetic acids tends to decrease.
If the temperature exceeds ℃, the mixture tends to boil and splashes tend to be scattered, which is not preferable. The heat retention time is usually about 0.1 to 4 hours, preferably about 0.5 to 2 hours.

The mixture after mixing with the acid thus contains:
Precipitates are present, which are crystals of the free acid of the phenylenedioxydiacetic acids.

Next, crystals of the free acid of phenylenedioxydiacetic acids are taken out. To take it out, for example, the mixture after mixing may be filtered. When taking out the crystal,
Usually, it is cooled to 0 ° C or more and 70 ° C or less, preferably 50 ° C or less.

The crystals taken out by filtration may be, for example, washed with water and then dried. The crystals of the free acid of the phenylenedioxydiacetic acids thus obtained have a low content of coloring components. Such crystals may be further purified by recrystallization or the like.

[0029]

According to the production method of the present invention, even if the reaction mixture after the reaction of halogenated acetic acids is mixed with an acid at a low temperature without using an antioxidant, the phenol having a small amount of a coloring component can be obtained. Rangeoxydiacetic acids can be produced.

[0030]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The dissolved oxygen concentration in the solution was measured using a galvanic cell type dissolved oxygen meter.

Example 1 A nitrogen gas was blown into a flask, and the oxygen partial pressure in the flask was adjusted to 0.004 MPa (0.04 atm) while maintaining the temperature at 20 ° C.
, 59.79 g (543 mmol) of resorcinol and 47.83 g of water (dissolved oxygen was 8 mg per kg of water) were added, and the mixture was stirred to dissolve resorcinol in water. Then
While maintaining the oxygen partial pressure in the flask at the same pressure and the temperature at the same temperature, 15.61 g (sodium hydroxide concentration: 190 mmol) of sodium hydroxide aqueous solution [sodium hydroxide concentration is 48% by weight] was added at the same temperature. PH in the system
Was set to 8.6.

Thereafter, the flask was heated to 95 ° C. while maintaining the oxygen partial pressure in the flask at the same pressure, and an aqueous sodium hydroxide solution (sodium hydroxide content was 48% by weight) was added to adjust the pH in the system to 8.8. 130.85 g of monochloroacetic acid (1385 mol) at the same temperature while being adjusted to be 0 to 8.5.
l) and 79.19 g of water were added dropwise over 5 hours, and then an aqueous sodium hydroxide solution (sodium hydroxide content was 48% by weight) was added to adjust the pH of the mixture.
Is adjusted to 8.0 to 8.5 at the same temperature.
After stirring for an hour, a reaction mixture (538.1 g) was obtained. This mixture was a slurry. The total amount of the aqueous sodium hydroxide solution used was 227.46 g (2769 mmol of sodium hydroxide).

Hydrochloric acid was added to the flask while stirring under a nitrogen atmosphere. The hydrogen chloride content was 32.81 g (900 mmol).
l)] 328.14 g was added thereto, the mixture was cooled to 20 ° C., and then 301.1 g of the reaction mixture obtained above was added over 1 hour, and washing water obtained by washing the flask used above with 33 g of water was added. Was. When the reaction mixture is added, the temperature in the system gradually increases, and after the addition, the temperature in the system is 32 ° C.
Met. The pH in the system is 1 or less.

Next, the mixture was heated to 88 ° C., kept at the same temperature for 1 hour, and then cooled to 40 ° C. After filtering the precipitated crystals, the crystals are washed with 300 g of water, dried in vacuo at 60 ° C., and 1,3-phenylenedioxydiacetic acid (61.8 g).
I got

5 g of the obtained 1,3-phenylenedioxydiacetic acid was dissolved in 25 cm ³ of an aqueous sodium hydroxide solution [containing 2 mol of sodium hydroxide in 1000 g of an aqueous solution], and water was added to reduce the volume to 50 cm ³ . The transmittance of the sample was measured at an optical path length of 100 mm.
It was 61.3% in nm.

Example 2 At 20 ° C., 59.79 g (543 mmo) of resorcinol was added while nitrogen gas was blown into the flask and the oxygen partial pressure in the flask was adjusted to 0.001 MPa or less (0.01 atm or less).
l) and water (dissolved oxygen is 8mg / kg of water) 4
7.83 g was charged, and the mixture was stirred to dissolve resorcinol in water. Next, while maintaining the oxygen partial pressure in the flask at the same pressure and the temperature at the same temperature, an aqueous solution of sodium hydroxide [concentration of sodium hydroxide is 48% by weight] 1 at the same temperature.
5.61 g (190 mmol of sodium hydroxide) was added to adjust the pH of the system to 8.1. Thereafter, the same operation as in Example 1 was performed to obtain a reaction mixture, and 1,3-phenylenedioxydiacetic acid was obtained.

The transmittance of the obtained 1,3-phenylenedioxydiacetic acid was measured in the same manner as in Example 1.
It was 61.5% at 00 nm.

Example 3 59.79 g (543 mmo) of resorcinol at 20 ° C. while nitrogen gas was blown into the flask to keep the oxygen partial pressure in the flask at 0.001 MPa or less (0.01 atm or less).
l) and 47.83 g of water (dissolved oxygen was 1 mg per kg of water (lower detection limit) or less) were added, and the mixture was stirred to dissolve resorcinol in water. Then, while maintaining the oxygen partial pressure in the flask at the same pressure and the temperature at the same temperature, 15.61 g of an aqueous sodium hydroxide solution [concentration of sodium hydroxide is 48% by weight] at the same temperature (sodium hydroxide is 190% by weight).
mmol) to adjust the pH of the system to 8.1. Thereafter, the same operation as in Example 1 was performed to obtain a reaction mixture.
3-Phenylenedioxydiacetic acid was obtained.

The transmittance of the obtained 1,3-phenylenedioxydiacetic acid was measured in the same manner as in Example 1.
It was 76.5% at 00 nm.

Example 4 At 30 ° C., 59.79 g (543 mmo) of resorcinol was added while nitrogen gas was blown into the flask and the oxygen partial pressure in the flask was adjusted to 0.004 MPa or less (0.04 atm or less).
l) and water (dissolved oxygen is 8mg / kg of water) 4
7.83 g was charged, and the mixture was stirred to dissolve resorcinol in water. Next, while maintaining the oxygen partial pressure in the flask at the same pressure and the temperature at the same temperature, an aqueous sodium hydroxide solution [concentration of sodium hydroxide is 48% by weight] 1 at the same temperature.
5.61 g (190 mmol of sodium hydroxide) was added to adjust the pH of the system to 8.1. Thereafter, the same operation as in Example 1 was performed to obtain a reaction mixture, and 1,3-phenylenedioxydiacetic acid was obtained.

The transmittance of the obtained 1,3-phenylenedioxydiacetic acid was measured in the same manner as in Example 1.
It was 59.9% at 00 nm.

Example 5 At 30 ° C., 59.79 g (543 mmo) of resorcinol was added at 30 ° C. while nitrogen gas was blown into the flask and the oxygen partial pressure in the flask was adjusted to 0.004 MPa or less (0.04 atm or less).
l) and water (dissolved oxygen is 8mg / kg of water) 4
7.83 g was charged, and the mixture was stirred to dissolve resorcinol in water. Then, while maintaining the oxygen partial pressure in the flask at the same pressure, 15.61 g (190 mmol of sodium hydroxide) of an aqueous sodium hydroxide solution [concentration of sodium hydroxide is 48% by weight] was added at the same temperature, and the pH in the system was increased. Was set to 8.1. After the addition of the aqueous sodium hydroxide solution, the temperature within the diameter was 42 ° C. Thereafter, the same operation as in Example 1 was performed to obtain a reaction mixture, and 1,3-phenylenedioxydiacetic acid was obtained.

The transmittance of the obtained 1,3-phenylenedioxydiacetic acid was measured in the same manner as in Example 1.
It was 61.7% at 00 nm.

COMPARATIVE EXAMPLE 1 A nitrogen gas was blown into a flask and the oxygen partial pressure in the flask was adjusted to 0.004 MPa (0.04 atm) while maintaining the temperature at 45 ° C.
, 59.79 g (543 mmol) of resorcinol and 47.83 g of water (dissolved oxygen was 8 mg per kg of water) were added, and the mixture was stirred to dissolve resorcinol in water. Then
While maintaining the oxygen partial pressure in the flask at the same pressure and the temperature at the same temperature, 15.61 g (sodium hydroxide concentration: 190 mmol) of sodium hydroxide aqueous solution [sodium hydroxide concentration is 48% by weight] was added at the same temperature. PH in the system
Was set to 8.1. After that, operating in the same manner as in Example 1,
A reaction mixture was obtained to obtain 1,3-phenylenedioxydiacetic acid (61.2 g).

The transmittance of the obtained 1,3-phenylenedioxydiacetic acid was measured in the same manner as in Example 1.
It was 45.0% at 00 nm.

Table 1 shows the results of Examples 1 to 5 and Comparative Example 1.
And Table 2.

[0047]

[Table 1]

[0048]

[Table 2]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuya Takada 3-1-198 Kasuganaka, Konohana-ku, Osaka F-term in Sumitomo Chemical Co., Ltd. 4H006 AA02 AC13 AC43 BB31 BC10 BC11 BC16 BJ50 BM30 BP30 4H039 CA61 CA65 CD10 CD20

Claims (5)

[Claims] 1. A compound of the general formula (II) (Wherein, R represents a halogen atom, a carboxyl group, or a hydrocarbon group having 1 to 4 carbon atoms, and n represents an integer of 0 to 4). General formula (I) characterized in that after mixing at a temperature of 40 ° C. or less, the mixture is reacted with a halogenated acetic acid. (Wherein, R and n each have the same meaning as described above). 2. The method according to claim 1, wherein an aqueous solution of an alkali compound is used as the alkali compound. 3. The method according to claim 1, wherein a mixture of dihydroxybenzenes and water is mixed with an alkali compound under an atmosphere having an oxygen partial pressure of 0.007 MPa or less. 4. The method according to claim 1, wherein the reaction with the halogenated acetic acid is carried out in an atmosphere having an oxygen partial pressure of 0.007 MPa or less. 5. A mixture of dihydroxybenzenes and water, the dihydroxybenzenes having a dissolved oxygen concentration of 4 ppm
The method according to claim 3 or 4, wherein the method is obtained by mixing with the following water.