JPH06345703A - Production of diaminodiphenyl ether - Google Patents

Abstract

PURPOSE:To provide a process for producing diaminodiphenyl ether which is useful as a starting material for aromatic polyamide to be used in the production of synthetic fibers or for medicines and agrochemicals efficiently in high yield. CONSTITUTION:In the production of diaminodiphenyl ether by condensation reaction between halonitrobenzene and aminophenol in the presence of a dehalogenation agent predominantly comprising alkali metal carbonate in a reaction medium, (a) an aprotic organic polar solvent is used as a reaction medium, and (b) the condensation reaction is effected, as an inert gas is blown into the reaction mixture. The condensation reaction between halonitrobenzene and aminophenol efficiently proceeds, even when the reaction temperature is relatively low, to suppress the formation of by-products whose separation from the target compound is difficult and troublesome whereby diaminodiphenyl ether of high purity can be produced in high yield.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing amino diphenyl ether. For more details,
Amino diphenyl ether with good productivity by conducting a condensation reaction of halonitrobenzene and aminophenol in an aprotic organic polar medium in the presence of an alkali metal carbonate while blowing an inert gas into the reaction mixture. The present invention relates to a novel method for manufacturing a.

[0002]

2. Description of the Related Art Amino diphenyl ether is a pesticide,
It is a useful substance as a raw material for medicines and polymer materials. As a method for synthesizing such amino diphenyl ether, amino nitro diphenyl ether is synthesized by reacting chloronitrobenzene and an alkali salt of aminophenol in an organic polar medium. The method has been known for a long time.

For example, JP-B-47-18101 discloses that para- or ortho-chloronitrobenzene is reacted with an alkali metal salt of aminophenol in an organic polar medium such as N, N-dimethylformamide to synthesize them. The method is described. However, this method uses an alkali metal hydroxide as a dehalogenating agent, uses aminophenol as an alkali salt, and makes the reaction temperature relatively low (50 to 80 ° C.) to suppress the production of by-products. However, there are problems such as slow reaction speed.

There has also been proposed a method of reacting an alkali metal aminophenate with ortho- or para-halonitrobenzene under reflux in a liquid reaction medium containing N, N-dimethylformamide (Japanese Examined Patent Publication No. Sho 5).
In this method, there is a problem in separation and recovery of N, N-dimethylformamide in the reaction medium because the reaction is carried out at a high temperature.

Further, by-produced water is removed from the reaction system by distillation of aminophenol and halonitrobenzene in an aprotic polar solvent in the presence of an alkali metal carbonate, preferably at 130 to 150 ° C. Alternatively, a method has been proposed in which a hydrocarbon is added to the reaction system and the condensation reaction is carried out while removing by-product water together with the hydrocarbon as an azeotrope outside the reaction system (Japanese Patent Publication No. Sho 63-19503). reference). However, in this method, the reaction is carried out while removing the by-product water together with the solvent by distillation to the outside of the system, which is disadvantageous in terms of operation, equipment and energy.

For the purpose of solving these problems, aminophenol and halonitrobenzene are added in a mixed solvent of N-methyl-2-pyrrolidone and water in a temperature range of 50 to 90 ° C. while adding an alkali metal hydroxide. A method of causing a condensation reaction has been proposed (see JP-A-62-81358). In this method, the reaction can be carried out at a relatively low temperature and the production of by-products can be suppressed, but in addition to the slow reaction rate, water has to be added to the reaction medium. In addition, there is a disadvantage in operation because the condensation reaction must be performed while adding the alkali metal hydroxide.

A method for producing a nuclear-substituted phenyl ether by reacting a specific nuclear-substituted phenol sodium with a nuclear-substituted chlorobenzene in the presence of an inorganic potassium salt has been proposed (Japanese Patent Publication No. 44-9660). reference),
This method is industrially disadvantageous because it requires the use of special raw materials.

[0008]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned problems in the conventional method, produces the amino diphenyl ether in a high yield with good productivity and advantageous operation and apparatus. It is intended to provide a way to do.

Therefore, an object of the present invention is to carry out a complicated operation of reacting halonitrobenzene and aminophenol at a relatively low temperature and adding an alkali metal hydroxide to a system in which the reaction is in progress. Also, without removing water by-produced during the reaction by distillation,
It is an object of the present invention to provide a method for industrially producing a desired amino diphenyl ether in a high yield.

[0010]

Means for Solving the Problems As a result of earnest research to achieve the above-mentioned object, the present inventor has found that by carrying out a condensation reaction between halonitrobenzene and aminophenol, amino.
In the method for producing diphenyl ether, it is possible to synthesize a target product in a high yield at a relatively low temperature by using a specific reaction medium and performing a condensation reaction while blowing a specific inert gas into the reaction condensate. They have found the present invention and reached the present invention.

That is, the present invention provides a method for producing an amino diphenyl ether by carrying out a condensation reaction of halonitrobenzene and aminophenol in a reaction medium in the presence of a dehalogenating condensing agent mainly composed of an alkali metal carbonate. , (A) an aprotic organic polar medium is used as a reaction medium, and (b) the reaction is carried out while blowing an inert gas into the condensation reaction mixture to produce an amino diphenyl ether with good productivity. .

Thus, according to the method of the present invention, the condensation reaction of halonitrobenzene and aminophenol can be efficiently carried out by blowing an inert gas into the reaction mixture during the condensation reaction even at a relatively low temperature. Moreover, since it is possible to carry out the reaction while removing water and / or carbon dioxide produced as a by-product during the reaction to the outside of the reaction mixture system, it is not necessary to remove the water to the outside of the reaction system by distillation. No need to add alkali metal hydroxide,
A method capable of carrying out a reaction and, in addition, suppressing the production of a by-product which is difficult and difficult to separate from a target product, and capable of producing a highly pure amino diphenyl ether in a high yield is provided. .

The method of the present invention will be described in detail below. The halonitrobenzene used in the method of the present invention includes para-
Chloronitrobenzene, para-bromonitrobenzene,
Examples include (mono) halonitrobenzenes such as para-iodonitrobenzene, and halonitroalkylbenzenes in which hydrogen of these benzene rings is substituted with a lower alkyl group such as a methyl group or an ethyl group.
Para-halonitrobenzenes, especially para-chloronitrobenzene, are preferably used.

Further, as aminophenol, meta-
Aminophenol, para-aminophenol, ortho-
Examples thereof include (mono) aminophenols such as aminophenol, and aminoalkylphenols in which hydrogen of these benzene rings is substituted with a lower alkyl group such as methyl group and ethyl group. Among them, meta-aminophenol Is preferably used.

In the method of the present invention, another object is to produce 3,4'-diaminodiphenyl ether useful as a raw material for aromatic polyamide fiber. In that case, para-chloronitrobenzene and meta- are used as starting materials. A combination with aminophenols is preferably selected.

The above-mentioned halonitrobenzene and aminophenol are preferably used alone, and on the other hand, when a mixture is used, the amino.
It becomes difficult to isolate the target substance with high purity from the diphenyl ethers. For example, in the condensation reaction of para-chloronitrobenzene and meta-aminophenol, if 2-5% of ortho-chloronitrobenzene is mixed in para-chloronitrobenzene, ortho-chloronitrobenzene reacts preferentially and is the target product. The purity of 3-amino-4-nitrodiphenyl ether is significantly reduced. And ortho-chloronitrobenzene and meta-
3-amino-a condensation product with aminophenol
When a wholly aromatic polyamide is produced by using 3,4'-diaminodiphenyl ether mixed with a few% of 2,3'-diaminodiphenyl ether obtained by reducing 2'-nitrodiphenyl ether, and fiberizing this, fiber performance is improved. It will be extremely low. Therefore, for the production of the polymer raw material for high-performance fibers, it is preferable to use high purity halonitrobenzene and aminophenol as a single product, and the purity is preferably at least 98 (wt)% or more. On the other hand, when it is used as a pesticide or other dispersant, it is not limited thereto, and 90 (weight)% or more, preferably 9
It may be 5% by weight or more.

The proportion of both components used in the condensation reaction of halonitrobenzene and aminophenol is 0.9 to halonitrobenzene relative to aminophenol.
It is preferably 1.1 times by mole, and more preferably 0.95 to 1.05 times by mole.

In the method of the present invention, the above-mentioned starting materials (halonitrobenzene and aminophenol) are used, and an inert gas is added in a reaction solvent in a specific reaction medium (medium) in the presence of a specific dehalogenating condensing agent. The condensation reaction is carried out while blowing into.

Here, an aprotic organic polar medium (medium) is used as the reaction medium (medium). As the aprotic organic polar medium (medium), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NM)
P), dimethyl sulfoxide (DMSO), sulfolane and the like. You may use these in mixture of 2 or more types as needed. A preferable aprotic organic polar medium (medium) is N, N-dimethylformamide (D
MF), N, N-dimethylacetamide (DMAc),
N-methyl-2-pyrrolidone (NMP), each of which is preferably used alone. The amount of these reaction media used is 0.5 to 20 times, preferably 1 to 10 times the total amount of halonitrobenzene and aminophenol.

On the other hand, specific examples of the alkali metal carbonate used as the dehalogenating condensing agent include potassium carbonate, potassium hydrogen carbonate, potassium sodium carbonate, sodium carbonate and sodium hydrogen carbonate. Further, carbonates obtained by mixing these carbonates with 1 to 30% by weight of an alkali metal hydroxide (for example, sodium hydroxide, potassium hydroxide, etc.) and carrying out firing treatment may be used. These dehalogenating agents are preferably used alone, but may be used in combination of two or more kinds. The purity of these carbonates may be 70 (wt)% or more, but preferably 85 (wt)% or more.

These dehalogenated condensing agents are preferably used after baking, dehydration and drying at 130 to 500 ° C.

The amount of the above-mentioned condensing agent used in the present invention is usually not less than the stoichiometric total amount of alkali metal carbonate or alkali metal hydroxide atom to 1 mol of aminophenol and preferably not more than 1.5 mol. Has a chemical equivalent of 1 to 3 times. If the amount exceeds 3 times, side reactions such as hydroxyl groups and nitro groups of phenol may occur, and the purity and yield of the target product tend to decrease.

In the present invention, examples of the inert gas blown into the reaction mixture during the condensation reaction include nitrogen, helium and argon, and among them, nitrogen gas is preferably used economically.

The purity of the inert gas is preferably as high as possible, and is preferably 99.99% or more, for example. In particular, it is necessary to avoid mixing of water and oxygen.

The aprotic, polar medium used in the present invention has a strong affinity for water, and when water is contained in the inert gas, it dissolves in the polar medium and the condensation reaction proceeds. The result will be frustrating. Therefore, the smaller the amount of water in the inert gas, the better. Normally, it is 0.01% or less. Also, if oxygen is mixed in the inert gas, the raw material aminophenol and the product can be obtained. The resulting amino groups are oxidized, resulting in coloring of the entire raw material. Therefore, the smaller the oxygen content, the better, and normally 0.01% or less is preferably used.

The method of blowing the inert gas into the reaction system mixture of the method of the present invention to remove the dissolved oxygen and the water by-produced by the condensation reaction and the carbon dioxide is referred to as introducing the inert gas into the reaction mixture. In the production of the target product with a simple operation, its effect is great from the viewpoint of improving the purity and yield. The inert gas may be blown in (introduced) continuously or intermittently during the condensation reaction, or before the condensation reaction, an inert gas may be introduced to remove moisture and water in the reaction medium. Alternatively, the condensation reaction may be started while removing dissolved oxygen in advance, and an inert gas may be continuously or intermittently introduced during the reaction.

The amount of the inert gas introduced into the reaction mixture is 0.1 to 50 liter / hr / M with respect to 1 mol of the total amount of the starting aminophenol and halonitrobenzene (M).
(1 mol) preferably 0.3 to 30 liters / hr / M
(1 mol). If the blowing amount is too small, the effect is small, and if it is too large, the loss of the inert gas becomes large, so an appropriate amount is selected within the above range.

The temperature of the condensation reaction varies depending on conditions such as the type of halonitrobenzene as a raw material, the type and amount of polar medium, and the type of condensation dehalogenating agent used, etc., but is usually 80 to 150 ° C., preferably 100. It is selected in the range of 140 ° C.

As described above, in the method of the present invention in which an alkali metal carbonate is used as a condensing agent in a specific reaction medium and a specific amount of an inert gas is introduced into the reaction mixture, halonitrobenzene and aminophenol are added. The condensation reaction proceeds efficiently, and monoamino / mononitro / diphenyl ether can be selectively produced.

In order to obtain monoamino / mononitro / diphenyl ether from the reaction mixture produced by the condensation reaction according to the present invention, it can be easily separated and taken out by a separation technique such as distillation, extraction or crystallization.

The monoamino / mononitro / diphenyl ether in the reaction mixture may be used as it is in the reaction mixture or after the by-produced alkali metal halide is separated.
It can be reduced with hydrogen in the presence of a catalyst such as palladium or platinum to give diamino diphenyl ether.

Therefore, according to the method of the present invention, para-chloronitrobenzene and meta-aminophenol are subjected to a condensation reaction to produce 3-amino-4-nitrodiphenyl ether, which is reduced as described above and useful as a wholly aromatic polyamide raw material. It is also possible to efficiently produce 3,4'-diaminodiphenyl ether.

[0033]

According to the method of the present invention as described above, the desired amino diphenyl ether can be efficiently produced without the problems of the conventional method.

[0034]

EXAMPLES The present invention will be described in detail below with reference to examples, but these are for explaining the present invention and the present invention is not limited thereto.

In Examples and Comparative Examples, 3-amino-4'-nitrodiphenyl ether (hereinafter, 3,
The yield (selectivity) of 4'-ANPE) and the conversion rate of meta-aminophenol (MPA) are the values obtained by gas chromatographic analysis.

[0036]

Example 1 (A) Preparation of Dehalogenating Condensing Agent: 1 mol of commercially available special grade potassium carbonate (purity of pure product 99.0%) and 9 mol of special grade potassium carbonate were mixed and pulverized, and the mixture was crushed at 200 ° C. for 1 hour. 45 more
The temperature was raised to 0 ° C., and baking and drying were performed for 5 hours.

(B) Condensation reaction (synthesis of 3,4'-ANPE): A 1-liter four-necked flask equipped with a stirrer, a thermometer, and a gas suction tube was charged with dimethylformamide 60.
0 ml of the condensing agent prepared as above was added to 34.
Charge 5 g (0.265 mol), heat to 120 ° C,
High-purity nitrogen (99.99% or more) was continuously introduced with stirring at a rate of 6 liters for 30 minutes to drive out water and oxygen dissolved in the solvent, and then 55 g of meta-aminophenol and para-chlorophenol were added. Charge 80 g of nitrobenzene,
At a temperature of 130 ° C., stirring was continued for 3 hours while introducing high-purity nitrogen gas at a rate of 5 liters per hour.

After completion of the reaction, the reaction mixture was analyzed by gas chromatography to find that the conversion of m-aminophenol was 98.2% and the selectivity of 3,4'-aminonitrodiphenyl ether was 99.0%. It was

(C) Reduction reaction (synthesis of 3,4'-diaminodiphenyl ether): 3,3 produced as described above.
After the reaction mixture containing 4'-ANPE was cooled to room temperature, the by-produced chloride was removed, and the reaction mixture was mixed with 5% P
0.5 g of the d / C catalyst was charged into an autoclave, and hydrogen reduction was carried out at a hydrogen pressure of 3 kg / cm ² G and a reaction temperature of 110 ° C. for 3 hours.

After the reaction was completed, the reaction solution was cooled to room temperature, and the produced 3,4'-diaminodiphenyl ether contained in the solution was analyzed and quantified by gas chromatography.
4'-ANPE is almost 100% 3,4'-diamino.
It had been converted to diphenyl ether.

[0041]

Examples 2 to 4 In Examples 1 (A) and (B), the composition and amount of the condensing agent, the amount of nitrogen introduced during the reaction, the reaction temperature and the time were changed as shown in Table 1 below. Reacted under the same conditions and conditions as in Examples 1 (A) and (B) to synthesize 3,4′-ANPE. The results are shown in Table 1.
Shown in.

[0042]

[Table 1]

[0043]

Comparative Examples 1 to 3 3,4'-ANPE was synthesized in the same manner as in Examples 2 to 4 except that the nitrogen gas was not blown into the reaction system. The results are shown in Table 2.

[0044]

[Table 2]

Claims (5)

[Claims] 1. A method for producing an amino diphenyl ether by carrying out a condensation reaction of halonitrobenzene and aminophenol in a reaction medium in the presence of a dehalogenating condensing agent mainly composed of an alkali metal carbonate. ) A process for producing an amino diphenyl ether, characterized in that an aprotic polar base medium is used as a reaction medium, and (b) the condensation reaction is carried out while blowing an inert gas into the reaction mixture. 2. The inert gas is nitrogen, hydrogen, helium,
The manufacturing method according to claim 1, which is at least one selected from argon. 3. Para-chloronitrobenzene is used as the halonitrobenzene and meta- is used as the aminophenol.
The production method according to claim 1 or 2, wherein aminophenol is used. 4. The production method according to claim 1, wherein the dehalogenating condensing agent is a mixture of an alkali metal carbonate and an alkali metal hydroxide, which is subjected to a mixed supporting and baking treatment. 5. Para-halonitrobenzene and meta-aminophenol are subjected to a condensation reaction in the presence of an alkali metal carbonate in an aprotic organic polar medium to produce 3-amino-4'-nitro diphenyl ether. And then reducing this with hydrogen to give 3,4'-diamino diphenyl ether. 5. The production method according to claim 1, claim 2, claim 3 or claim 4.