JPS59148741A - Production of aromatic amine - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high efficiency, by reacting an aromatic halide with ammonia in the presence of water using a catalyst composed mainly of copper oxide, etc., extracting and separating the objective product from the reaction mixture, and precipitating the copper compound with an alkali metal hydroxide, etc. CONSTITUTION:An aromatic amine is prepared by ( I ) reacting an aromatic halide with ammonia in the presence of water using a catalyst composed mainly of a copper oxide and/or a copper halide, (II) separating the aromatic amine from the reaction mixture obtained by the step I by extraction, and (III) adding an alkali metal hydroxide and/or alkaline earth metal hydroxide to the residual aqueous solution left after the extraction process, and separating the precipitated copper compound from the solution. The catalyst can be recovered in high recovery and reused as a catalyst. The waste liquid treatment after the recovery of the catalyst can be carried out easily, and there is no degradation and loss of the objective compound during the recovery of the catalyst.

Description

[Detailed description of the invention] The present invention relates to a method for producing aromatic amines.

Conventionally, as a method for producing aromatic amines, a method is known in which an aromatic halide and ammonia are reacted in the presence of water using a copper compound as a catalyst. However, a particular problem in this method is the separation and purification of the reaction product and the copper compound catalyst after the reaction, and many proposals have been made in this regard.

For example, in the literature (edited by Kirk Othmer, "Engineering/Cyclobedea Opchemical Technology," Vol. 2, p. 361), excess ammonia is first removed from the reaction product liquid, and then sulfide is added to the catalyst. A method has been proposed in which a copper compound is precipitated as copper sulfide and then aromatic amines are extracted, and in West German Patent No. 654395, sulfide is added together with sodium hydroxide to the reaction product liquid to remove the catalyst. A method has been proposed in which a copper compound is precipitated as copper sulfide, this is filtered off, and then an aromatic amine is crystallized and separated. These methods recover the copper component of the catalyst as sulfide. However, in these methods, the recovered copper sulfide has a low activity as a catalyst and cannot be reused. However, it is difficult to implement it industrially due to problems in its disposal.

Furthermore, a method that overcomes the drawbacks of the above-mentioned methods and allows the recovered copper compound to be reused as a catalyst is disclosed, for example, in Japanese Patent Publication No. 55-33707 and Japanese Patent Publication No. 55-33.
This method has been proposed in Japanese Patent No. 708 and Japanese Patent No. 55-33709. In these methods, first, an alkali metal hydroxide is added to the reaction product liquid to precipitate the copper component of the catalyst as a copper oxide, and then the target substance is separated by distillation or extraction. The copper oxide recovered by this method is effective as a catalyst and can be reused. However, these methods have the disadvantage that the precipitated copper oxide is in the form of a colloid, making it difficult to separate, and furthermore, a considerable amount of copper ions that do not form a precipitate remain in the reaction product solution. Therefore, there are problems in that an additional treatment step for removing the kabura ions is required in the disposal of the residual liquid after separating the precipitation of copper oxides and the target substance.

Furthermore, in JP-A-51-59824, rather than separating the copper component of the catalyst by precipitating it, a part of ammonium chloride, which is a by-product present in the reaction product liquid, is crystallized and separated. A method has been proposed for reusing the remaining liquid containing the catalyst.

However, this method has the disadvantage that the reused residual liquid contains a large amount of ammonium chloride, which reduces the reaction rate of the desired reaction and reduces the selectivity. In addition, the separated ammonium chloride contains a small amount of copper component11, and since it is a regression process to completely remove this copper component even by operations such as recrystallization, the ammonium chloride obtained is Ammonium chloride cannot be used for purposes such as fertilizers, and the problem is that it is not easy to dispose of ammonium chloride.

In this way, although the method for producing aromatic amines from aromatic halides and ammonia is easy to obtain raw materials and can obtain the target substance in a few steps, it does not work as described above. Various problems remain, and it has not yet been industrialized.

The present invention was made against the above background, and its purpose is to efficiently produce aromatic amines in which the catalyst can be reused and there are no problems with waste disposal. The purpose is to provide a method.

That is, the present invention provides a method for producing an aromatic amine from an aromatic halide and ammonia, including the following step α).
, (2) and (3).

Step (1): A step of reacting an aromatic halide and ammonia in the presence of water using a catalyst mainly composed of copper oxide and/or copper halide.

Step ('4: Step of extracting and separating the aromatic amine in the reaction product liquid obtained in step (1).

Step (3): A step of adding an alkali metal hydroxide and/or an alkaline earth metal hydroxide to the aqueous solution remaining after the extraction operation obtained in step (2) to precipitate and separate a copper compound.

Next, the present invention will be explained in detail.

In the present invention, first, an aromatic halide and ammonia are reacted in the presence of water using a catalyst mainly composed of copper oxide and/or copper halide.

Next, after cooling the obtained reaction product liquid, aromatic amines and other aromatic compounds, which are the target substances, are separated by solvent extraction, and aromatic amines and amines are further separated from this extract by operations such as distillation. do. On the other hand, an alkali, that is, an alkali metal hydroxide and/or an alkaline earth metal hydroxide, is added to the residual aqueous solution after the solvent extraction operation to precipitate a copper compound mainly consisting of copper oxide, and the precipitated copper Separate the compound and reuse it as a catalyst. Thereafter, the aromatic amine is produced by repeating the above steps. Examples of aromatic halides in the present invention include chlorobenzene, dichlorobenzene, trichlorobenzene, chloroaniline, dichloroaniline, chlornitrobenzene, and dichloronitrobenzene. Preferred aromatic halides include chlorobenzene, Mention may be made of dichlorobenzene, chloroaniline, and trichlorobenzene.

These aromatic halides can be used in combination.

The amount of ammonia used is preferably 2 to 25 mol, particularly preferably 4 to 20 mol, per several grams of halogen that requires ammonolysis of the aromatic halide.

The amount of water used is preferably 30 to 70%, particularly preferably 45 to 70%, based on the weight sum of both ammonia and water.
It is 65 Jukei Chi.

The amount of copper oxide and/or copper halide used is preferably 0 as copper atoms per mol of aromatic halide.
．． 0.01 to 0.40 gram-atom, particularly preferably 0.0
2 to 0.20 grams-atom. As copper oxide,
Examples include cuprous oxide and cupric oxide. Examples of the copper halide include cupric halides, cupric halides, and compounds prepared by dihalogenating cuprous oxide or cupric oxide with hydrogen halide.

The reaction temperature of the aromatic halide and ammonia in the present invention is preferably 170 to 250°C, particularly preferably 2
The reaction time is usually 4 to 40 hours. When carrying out the reaction continuously, it is preferable to connect two or more reactors in series so that the residence time of the reaction solution in the reactor becomes the desired reaction time.

After the reaction is completed, the reaction product solution obtained is preferably 0 to 8
Cooling to 0°C, particularly preferably 20-60°C, then
For example, aromatic amines, chloraniline, aniline, etc., which are the target substances, can be used with alcohols having 3 to 6 carbon atoms in the main chain such as propatool, butanol, pentanol, and hexanol, and solvents whose main components are aniline or aniline d conductors. Extract remaining raw materials or intermediates such as dichlorobenzene.

Note that other organic solvents such as propyl ether, butyl ether, etc. can be added to the solvent used for extraction in order to reduce the solubility of water and by-product ammonium chloride in the solvent. In addition, prior to the extraction operation, ammonia in the reaction product liquid can be removed as a gas by returning the reaction system to normal pressure if necessary, and the pressure during the extraction operation can be reduced. There is no need to remove the ammonia inside.

From the obtained extract, the target substance, aromatic amine, is separated by operations such as distillation. Note that dichlorobenzene, chlorobenzene, chloroaniline, aniline, ammonia, etc. extracted at the same time are also isolated as necessary.

Chloraniline and aniline can be used as purified products. Chlorbenzene may be used as a product, but
It can be converted to dianiline by reacting again. Chloraniline may also be reused as a raw material together with dichlorobenzene and ammonia.

On the other hand, the residual aqueous solution after the solvent extraction operation is usually heated to remove the solvent and unextracted aromatic compounds, for example by azeotropic distillation.
After removing by a method such as steam distillation, alkali metal hydroxide and/or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, etc., preferably an alkali, are removed while stirring thoroughly. A metal hydroxide is added to make the solution alkaline, preferably at pHlo or higher, particularly preferably at pH12 or higher, so that the copper component in the remaining aqueous solution is precipitated as a copper compound mainly consisting of copper oxide. In this process, the temperature is generally set at 6.5 cm in order to speed up the precipitation of the copper compound and further increase the particle size of the precipitated copper compound to facilitate its separation.
The operation is carried out at 0° C. or higher, preferably at the boiling point of the residual aqueous solution, and steam may be blown in if necessary. Furthermore, in the copper compound precipitation step, the precipitation of the copper component is further promoted by blowing a non-condensable gas such as air or nitrogen into the residual aqueous solution at a temperature of 50° C. or higher, preferably at the boiling point of the residual aqueous solution. , the unprecipitated copper component present in the residual aqueous solution can be further reduced.

The precipitated copper compound is separated and recovered by decantation or filtration. The recovered copper compound is a mixture of cupric oxide and toned hydroxide. The recovered copper compound has substantially the same catalytic activity as cupric oxide, and can be reused as it is as a catalyst mainly composed of copper oxide in the method of the present invention. When this recovered copper compound is reused as a catalyst, it is preferable to treat it with hydrogen halide in order to further increase the catalytic activity and use it as a halogenated copper oxide compound in the method of the present invention. Hydrogen halides include hydrogen chloride, hydrogen bromide, etc. The amount of hydrogen halides used is preferably 0.1 to 3 mol per gram of copper per atom in the copper compound, particularly preferably 0.1 to 3 mol. 0.5~2
It is a mole. The method for treating a copper compound with hydrogen halide is not particularly limited, but for example, a copper compound and hydrogen halide are mixed in water, and preferably 40 to 100
A method of heating at °C and stirring can be mentioned.

On the other hand, since the amount of copper ions contained in the waste liquid after separating the precipitated copper compounds is extremely small, normal wastewater treatment,
For example, it can be easily treated by activated sludge treatment or activated carbon treatment.

As described above, according to the present invention, aromatic compounds such as aromatic amines are first separated from the reaction product liquid, and then a copper compound catalyst mainly composed of cupric oxide is separated and recovered. It is possible to achieve the following effects.

(1) In the copper compound catalyst separation/recovery process, the particle size and apparent specific gravity of the precipitated copper compound are large, so the separation operation can be carried out smoothly and in a short time, making it efficient. '(2) In the copper compound catalyst separation/recovery process, the recovery rate of the copper compound is high, and the recovered copper compound can be effectively reused as a catalyst.

(3) Since the amount of copper remaining in the waste liquid is small, subsequent treatment of the waste liquid is easy.

(4) In order to separate the target aromatic amines and other aromatic compounds before proceeding to the copper compound catalyst recovery process, these useful substances are subjected to alkali treatment etc. in the subsequent catalyst recovery process. It is advantageous because it does not undergo any alteration or loss through various operations.

Hereinafter, the present invention will be explained by examples.

Example 1 O-y" chlorobenzene 1502.
40% by weight ammonia water 3751, cupric oxide7. Of
was charged, heated to 220°C, and reacted for 12 hours.

After the reaction, the autoclave was cooled to 30° C., and the pulp was opened little by little while stirring to release excess ammonia gas. After lowering the pressure to normal pressure, the reaction product solution in the autoclave was transferred to another container and stored. The reaction rate was 95%, the selectivity was 79% for 0-phenylenediamine, and 1 for o-chloroaniline.
4.5%, aniso 73.7%. This reaction is 10
The mixture was circulated, and the resulting reaction product liquids were mixed. Next, using a vertically vibrating countercurrent liquid-liquid extractor having an inner diameter of 15 m and an effective height of 2.0 m, the reaction product liquid IKf was extracted with n-butanol IKf. The extraction rate of 0-phenylenediamine was 98%. Next, the residual aqueous solution after the extraction operation was transferred to a flask and distilled. The distillate was separated into two layers, the aqueous layer was refluxed into the flask, and only the organic layer was removed. Since the distillate did not separate into layers and only became an aqueous layer, I poured 100 - of water into the flask and added another 10
0- water was distilled out.

Next, 640 ml of a 925% by weight aqueous sodium hydroxide solution was added dropwise to the upper part of the flask while refluxing the content inside the flask. At this time, ammonia gas was generated. The content became a black suspension. After refluxing for 15 minutes, the mixture was allowed to cool, and a black copper compound consisting mainly of cupric oxide was precipitated. A small amount of the clear supernatant liquid was taken out and the dissolved copper content was measured, and the concentration was 50 ppm. Also, this liquid was p
It was H12.1. While the flask was heated again to reflux, air was bubbled through the contents for 1 hour. The flask was allowed to cool, and the contents were filtered to recover a copper compound mainly composed of cupric oxide. The recovery rate was approximately 100 cm based on the calculated metallic copper content. Filtration was easy.

When a portion of the p solution was removed and the dissolved copper content was measured, the concentration was 6 ppm.

In addition, the recovered copper compound was washed again with distilled water and dried. 7. The copper compound obtained by drying this. Of and many, O-dichlorobenzene 150 F, 40% by weight aqueous ammonia 37
5t and heated at 220℃ in the autoclave for 13 minutes.
When the reaction was carried out for a period of time, the reaction result was a conversion rate of 95.2.
%, selectivity is 0-phenylenediamine 79%, 0-10
They were approximately the same as the original ones, with 14 ts of luaniline and 4 ts of aniline.

Example 2 150 f of 0-dichlorobenzene and 2 ml of water were placed in a stainless steel autoclave with an internal volume of 1 t equipped with an electromagnetic rotary stirrer.
25 F, ammonia 150f, cupric chloride hydrate 1
The reactor was filled with 51F, heated to 220°C, and reacted for 8 hours. After the reaction, the autoclave was cooled to 30°C and the pulp was opened little by little while stirring to release excess ammonia gas. After lowering the pressure to normal pressure, the reaction product solution in the autoclave was transferred to another container and stored. The reaction rate was 97.5%, and the selectivity was 79.1% for O-phenylenediamine, 14.1% for O-chloroaniline, and 3.7% for aniline. This reaction was repeated 10 times, and the resulting reaction product liquids were mixed. Next, using a vertically vibrating countercurrent liquid-liquid extraction device with an inner diameter of 15 mm and an effective height of 2.0 m, the reaction product liquid lK9 was
Extract Natsuta using 1 t of butanol. The extraction rate of 0-phenylenediamine was 98%. Next, the aqueous solution remaining after the extraction operation was transferred to a flask and distilled. The distillate was separated into two layers, and the aqueous layer was refluxed into the flask to remove only the organic layer. After the distillate does not separate into layers and becomes only an aqueous layer, add 100ml of water dropwise into the flask, and add 100ml of water to the flask.
After distilling off the water in the flask, 925 by weight of an aqueous solution of sodium hydroxide, 700 by weight, was added dropwise to the upper part of the flask while refluxing the liquid inside the flask. At this time, ammonia gas was generated. The content became a black suspension. Further reflux for 15
When the mixture was left to cool for a few minutes, a black copper compound mainly composed of cupric oxide precipitated. A small amount of the transparent supernatant liquid was taken out and the dissolved copper content was measured, and the concentration was 50 ppm. Moreover, this liquid had a pH of 12.0. The flask was heated again to reflux while air was bubbled through the contents for 1 hour. The flask was allowed to cool, and the liquid content was filtered to recover a copper compound mainly composed of cupric oxide. The recovery rate was almost 100% based on the calculated metallic copper content. Filtration was easy. When I measured the dissolved copper content of part of the F solution, it was found to be 6pp.
The concentration was m.

In addition, the recovered copper compound was washed again with distilled water and dried.

The dried copper compound was placed in a 7.0ftl Erlenmeyer flask, and 5% by weight aqueous hydrochloric acid solution 64.3F (1 gram of copper in the copper compound - equivalent to 1 mole of hydrogen chloride per atom) was added and stirred for 10 minutes. Thereafter, the temperature was raised to 50° C. and stirred for 30 minutes to obtain a gray suspension.

This suspension was transferred to the above autoclave, and further added 150 F of 0-dichlorobenzene, 225 t of water, and 1 t of ammonia.
The reactor was filled with 50F and reacted at 220°C for 8 hours. The reaction results were that the conversion rate was 95%, and the selectivity was 78% for 0-phenylenediamine, 15% for 0-I rollaniline, and 4% for aniline, which were almost the same as the original ones.

Comparative Example 1 A 25% by weight aqueous sodium hydroxide solution was added dropwise to the reaction product liquids 1 to 1 obtained in Example 1 to adjust the pH of the reaction product liquid to 12.5 to precipitate a copper compound. . The precipitate was colloidal. The reaction product solution containing this precipitate was subjected to azeotropic distillation to recover 0-dichlorobenzene, O-chloroaniline, chlorobenzene, and aniline. In the azeotropic distillation, water was added so that the concentration of 0-phenylenediamine in the reaction product liquid was always 5 to 20% by weight.

O-phenylenediamine in the residual liquid after the azeotropic distillation was extracted using n-butanol IKf using a vertically vibrating countercurrent liquid-liquid extractor having an inner diameter of 15 cm and an effective height of 2.0 m. The above precipitated copper compound was present in colloidal form in the residual aqueous solution after the extraction operation. The copper compound in this residual aqueous solution was separated by suction filtration and 95% of metal copper was recovered, but the suction filtration took a long time. Further, when the dissolved copper content in the F solution was measured, it was found to be aooppm.

Procedural amendment. a.

Kazuo Wakasugi, Commissioner of the Japan Patent Office, September 29, 1980 1 Display of the case 1981 Rei Gan No. 22052 "2. Title of the invention Process for producing aromatic amines 3, Relationship with the amendment person's case Patent applicant furigana 2-11-24 Tsukiji, Chuo-ku, Tokyo Address Name (417) Japan Synthetic Rubber Co., Ltd. 4,
Agent 5, date of amendment order 6, number of inventions that will increase due to the amendment is corrected to ``60℃J.

(2) In the third line of page 14, "n-butanol IKg" is corrected to "n-butanol 2KrJ."

(3) In the first line of page 16, ``30℃J'' is corrected to ``60℃.''

(4) In the same page 16, line 10, ``n-butanol Ill is corrected to ``n-butanol 2KvJ.''

(5) On page 18, lines 18 to 19, [n-butanol 1-] has been corrected to "n-butanol 2 Kq J."

Claims (1)

[Scope of Claims] 1) A method for producing an aromatic amine from an aromatic halide and ammonia, which comprises the following steps (1), (2), and (3). !
Healing process (1): A process of reacting aromatic halide and ammonia in the presence of water using a catalyst mainly composed of copper oxide and/or copper halide. Step (2): A step of extracting and separating the aromatic amine in the reaction product liquid obtained in step (1). Step (3): A step of adding an alkali metal hydroxide and/or an alkaline earth metal hydroxide to the aqueous solution remaining after the extraction operation obtained in step (2) to precipitate and separate a copper compound.