JPS60149549A - Preparation of aminodiphenyl ether - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for dyes, agricultural chemicals and medicines and a crosslinking agent for plastics, by easy separating operation, by reducing a nitrodiphenyl ether with hydrogen while forming a heterogeneous mixture in the presence of a solvent soluble slightly in a raw material compound. CONSTITUTION:A nitrodiphenyl ether is brought into contact with hydrogen in the presence of a hydrogen reducing catalyst, preferably Pd catalyst, in a heterogeneous system consisting of a solvent, soluble slightly in the above-mentioned compound, and capable of forming a heterogeneous mixture in the reaction system and further a heterogeneous reaction product mixture even after the complation of the reaction, e.g. water, aliphatic hydrocarbon such as hexane, or alicyclic hydrocarbon such as decalin, and the resultant heterogeneous reaction product mixture is separated into phases. The contained catalyst is removed to give the aimed compound. The above-mentioned solvent is preferably used in an amount of 100-400pts.wt. based on 100pts.wt. nitrodiphenyl ether.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing aminodiphenyl ethers.

The aminodiphenyl ethers obtained by the present invention are useful as dyes, medicines, agricultural chemicals, raw materials for synthetic resins, bifunctional crosslinking agents for plastics and elastomer containers, and network spreading agents.

Conventionally, as a method for producing aminodiphenyl ethers, a method in which nitrodiphenyl ethers are reduced with hydrogen in a liquid phase has been widely adopted.

In order to make this hydrogen reduction reaction proceed smoothly, a method is generally adopted in which a solvent that is soluble in the raw material nitrodiphenyl ether is used and the entire reaction is carried out under homogeneous liquid phase conditions. No. 55-40573 proposes a method using dimethylformamide as a solvent having high solubility for nitrodiphenyl ethers and aminodiphenyl ethers. However, since dimethylformamide is freely miscible with the water produced by the hydrogen reduction reaction, it has the disadvantage that water must be separated and removed by distillation in order to use this solvent repeatedly.

As an improved method of this method, Japanese Patent Application Laid-Open No. 54-8822
8 and JP-A No. 54-106439 Niha, acetic acid-2-ethoxy ether and the like are highly soluble in nitrone phenyl ethers and aminodiphenyl ethers, and are immiscible with the water produced in the hydrogen reduction reaction. glycol monoether monoesters,
Alternatively, methods using cyclic ethers such as dioxane and tetrahydronsine, or fatty acid esters such as ethyl acetate have been proposed. This method has the advantage that the solvent can be recycled and reused by removing the produced water from the solvent through a simple operation called oil-water separation.However, when separating aminodiphenyl ethers, which are hydrogen reduction reaction products, There is a drawback that, in addition to the catalyst, the solvent must be removed from the reduction reaction mixture obtained after the completion of the reaction by a complicated operation of distillation.

The present inventors recognized that the previously proposed homogeneous liquid-phase hydrogen reduction reaction method for nitrodiphenyl ethers has the above-mentioned drawbacks, and they As a result of intensive studies on methods for separating diphenyl ethers, we found that the above objective could be achieved by forming a heterogeneous system in the reaction system in the presence of a solvent that is poorly soluble in the raw material nitrodiphenyl ethers. We have discovered what can be achieved and arrived at the present invention.

That is, to summarize the present invention, the present invention comprises: (2) reducing the o group to an amine group and converting the corresponding aminodiphenyl ether by contacting the nitrodiphenyl ether with hydrogen in the presence of a hydrogen-reducing catalyst; In the method for producing nitrodiphenyl ethers, a solvent that is poorly soluble in the nitrodiphenyl ether is present under hydrogen reduction reaction conditions, and the hydrogen reduction is performed while forming a heterogeneous mixture consisting of the nitrodiphenyl ether and the solvent. The gist of the invention is a method for producing aminodiphenyl ethers, which is characterized by conducting a reaction to obtain a heterogeneous reaction product mixture, and separating diaminodiphenyl ethers by phase-separating the reaction product mixture. . This will be explained in detail below.

The nitrodiphenyl ethers used in the process of the invention are diphenyl ethers containing at least one nitro group or substituted products thereof, such as 6-amino-
4'-nido-l codine enyl ether/l/, 3--amino-6'-nitrodiphenyl ether, 4-7 mi/-
4'-Nitrodiphenyl ether, 4-amino-6'-
Nitrodiphenyl ether, 2-amino-4'-nitrodiphenyl ether, 2-ami/-3'-nitrodiphenyl ether, 2-7mi/-2'-=)rodiphenyl ether, 2-nitrodiphenyl ether, 6-nitrodiphenyl ether, 4-nitrodiphenyl ether,
3. '4'-dinitro diphenyl ether, 2,4'-
Cinitrodiphenyl ether 4.4'-Cinitrodiphenyl ether 4-chloro-41-nitrodiphenyl ether, nonoro-41-nitrodiphenyl ether 4--ri o7+z-3'-nitrodiphenyl ether, 4-fromo2 '-Nitrodiphenyl ether, 4
-)f-4'-nitrodiphenyl ether, 21o-5-methyl-4'-nitrodiphenyl ether,
3-(N,N-7methylamine)-4'-nitrodiphenyl ether, 3-(N,N-dimethylamino)-31
-nitrodiphenyl ether, 4-(N.

N-dimethylamino)-4'-nitrodiphenyl ether, 4-(JN-dimethylamino)-6'-nitrodiphenyl ether, 3-(N,N-diethylamino)-4
'-Nitrodiphenyl ether, 6-(N,N-diethylamino), +-nitrodiphenyl ether, 4-(
Examples include N,N-diethylamino)-4'-nitrodiphenyl ether and 4-(N,N-diethylamino)-3'-nitrodiphenyl ether.

The hydrogen reduction catalyst used in the method of the present invention is, for example, a metal of Group I of the periodic table, such as C-nickel, Raney cobalt, platinum oxide, platinum, palladium, or rhodicum, or a compound of the metal. This can be achieved by preparing a catalyst that uses hydrogen as an active component in the hydrogen reduction reaction. These active ingredients are supported by various carriers, such as alumina, quartzite, activated carbon, inorganic or organic fibers, metal oxides such as lucium carbonate, silica, aluminium oxide, barium sulfate, and titanium oxide. ! The moss may be used as a support on a metal salt or an organic polymer resin, or the active ingredient 7 moss may be used alone. Among these catalysts, palladium carriers with high activity at low temperatures, especially those supported on carriers such as activated carbon or alumina, are used.
It is preferable to use a palladium catalyst. The state of palladium before being used in the catalytic total hydrogen reduction reaction may be palladium black (metal), oxide, or halocunide;
For the hydrogen reduction catalyst 6, it is particularly preferable to use the firefly-shaped badges 9, which are black and dispersed on the carrier. The amount of palladium supported on the palladium catalyst supported on the carrier described above is calculated as (
Parasiwa parasiwa 11I amount/carrier weight), which is usually in the range of 0.5 to 5 weight.

In the method of the present invention, the sparingly soluble solvent used in the hydrogen reduction reaction flows into the nitrodiphenyl ethers under the hydrogen reduction catalyst, forming a heterogeneous mixture in the reaction system. In addition, it is a solvent that forms a heterogeneous reaction product mixture even after the completion of the reaction, and more preferably a solvent that is sparingly soluble for both the nitrodiphenyl ethers and the aminodiphenyl ether, and that is suitable for the reaction system. It is a solvent that forms a heterogeneous mixture in the process and also forms a heterogeneous reaction product mixture even after the reaction is completed. Specific examples of the poorly soluble solvent include water, alicyclic hydrocarbons such as hexane and heptane, and alicyclic hydrocarbons such as cyclohexipune and decalin. These poorly soluble solvents may be used alone or in combination with a@-1, but among these poorly soluble solvents, it is preferable to use water. The amount of the poorly soluble solvent to be used is 7 to 9 parts per 1001 parts by weight of the nitrodiphenyl ether, usually 50 to 1000 parts by weight, preferably 100 to 400 parts by weight.

In the method of the present invention, the hydrogen reduction reaction is carried out by contacting a heterogeneous mixture consisting of the raw material nitrodiphenyl ethers and the poorly soluble solvent with hydrogen in the presence of an HC hydrogen reduction catalyst. Ru. Here, the heterogeneous mixture means that the 2) o diphenyl ethers are the ki,
While dispersed in a wet solvent, a liquid-liquid heterogeneous mixture may be formed, or a one-liquid heterogeneous mixture may be formed, but liquid-liquid Preferably, a heterogeneous mixture is formed. During the reaction, these heterogeneous mixtures are preferably in a finely dispersed state while being stirred.

Uninvented method Q (in which the hydrogen reduction reaction is preferably carried out by suspending the hydrogen reduction catalyst in a heterogeneous mixture consisting of the nitrodiphenyl ethers and the poorly soluble solvent and introducing hydrogen At that time, the amount of hydrogen reduction catalyst used is usually 0.01 to 1 g, preferably 0.01 to 1 g, per 11 of the mixed liquid, and expressed in terms of palladium, which is an active component of the melting medium excluding the carrier. Shikurl:0.0
It is best to use it in a range of 5 to 0.5 g. The hydrogen pressure when carrying out the hydrogen reduction reaction is usually 0.5 in absolute pressure.
150kf/aJ to 150kf/aJ, preferably 1 to IU absolute pressure
It is best to maintain it within the Okp/cdt range. In this case, in addition to the method of using hydrogen alone, an inert gas such as nitrogen, helium, or argon may be used together with hydrogen.

To carry out the hydrogen reduction reaction in the method of the present invention, any type of reactor to which batch, semi-batch, or continuous methods can be applied can be used as long as it is equipped with a hydrogen inlet and four stirring devices. May be used.

The catalyst suspended in the heterogeneous mixture consisting of the nitrodiphenyl ethers and the poorly soluble solvent and the unrestricted mixture is brought into contact with hydrogen by a commonly known stirring method. be able to. Specifically, H''J includes a stirring blade method in which the stirring blade is rotated or vibrated, a stirring method in which inert gas is ejected from the lower part of the reactor, etc. Methods such as stirring the liquid by moving it or flowing it can be adopted.

The method of the present invention vC seconds and the reaction temperature of the / The reaction time varies somewhat depending on the reaction pressure, amount of catalyst, reaction temperature, stirring method, etc., but is usually from 0.5 to 15 hours.

In the method of the present invention, as a result of the hydrogen reduction reaction, the nitro group of the nitrodiphenylnials is reduced to the haamine group. Aminophenyl ethers are formed, and a heterogeneous reaction product mixture is obtained. The heterogeneous reaction product mixture contains, in addition to the aminodiphenyl ethers, the di-W-soluble solvent, and the catalyst, the unreacted di]-rodiphenyl ethers. The heterogeneous reaction product mixture consists of a liquid phase mainly consisting of the poorly soluble solvent and a phase consisting of a mixture of the aminodiphenyl ethers and the unreacted nitrodiphenyl ethers (hereinafter, this phase is referred to as the reduction product mixture phase). ), and the catalyst described above.

The separation of the aminodiphenyl needles obtained by the method of the present invention is carried out in a state in which the heterogeneous reaction product mixture is a two-liquid phase mixture in which an insoluble catalyst is suspended, that is, the reduction product mixture is in a liquid phase. This can be carried out by a separation method of separating the phases of the reduction product oil (hereinafter sometimes referred to as reduction product oil). In this case, as a method for converting the heterogeneous reaction product mixture into the two liquid phase V, the following methods can be selected as appropriate.

(2) The heterogeneous reaction product mixture is maintained at a temperature at which the average reaction product mixture forms the two-liquid phase mixture, that is, the reduction product mixture phase forms a solid mass and does not precipitate.

■When water is used for the poorly soluble elution, an appropriate amount of a water-insoluble solvent such as toluene or xylene may be added to the heterogeneous reaction product mixture to form a solvent-independent reaction product mixture. . In this case, the mixture is maintained at a temperature at which the solvent-added heterogeneous reaction product mixture forms a two-liquid phase mixture. The phase separation operation in the method of the present invention includes, for example,
This can be carried out by the method of Tsunae, which utilizes differences in specific gravity due to oil/water separation. In this case, a filter is used during the phase separation operation to simultaneously separate and remove the catalyst mixed in the reduction product oil or the reduction product oil containing the solvent (hereinafter these may be referred to as reduction product oil, etc.). It's okay. In separating the reduction product oil, etc., the catalyst in the two-phase mixture may be removed by filtration or the like, and then the reduction product oil, etc. may be separated. Regarding the method for separating the reduction product oil that is poor in the 7' minodiphenyl ethers,
Apart from the above-described method of converting the heterogeneous reaction product mixture into a two-liquid phase mixture, the following method can also be used if necessary. In a state where the reduction product mixture phase in the heterogeneous reaction product mixture is precipitated as a solid lump containing the catalyst, after separating the precipitate, toluene and xylene are added to the precipitate. The solvent is removed by adding an appropriate amount of a solvent such as F to dissolve the reduction product mixed phase to obtain a mixed solution containing the catalyst, and then removing the catalyst f from the mixed solution by Δ filtration or the like. It is possible to obtain a reduced product oil.

The reduced oil etc. can be obtained by any of the above methods. The reduction product oil, etc. may be washed with the slightly soluble solvent as necessary. In the method of the present invention, the heterogeneous reaction shown in The temperature at which the product mixture is kept warm by the illuminance and the solvent-saturated heterogeneous reaction product mixture varies depending on the type of nitrodiphenyl ether used in the hydrogen reduction reaction of the present invention, but is usually 70°C. to 190°C. For example, as a nitrodiphenyl ether, amino-4! When nitrodiphenyl ether is used, the insulating temperature is preferably between 70 and 9°C.

The catalyst recovered by the above-described separation operation may be washed with the dissolvable solvent as necessary, and after the above operation, washed with a solvent such as methanol as necessary, and then used again. In addition, the recovered liquid recovered by the phase separation operation, which mainly consists of a difficult-to-bath solvent, is left as it is.
A part of the recovered liquid can be exchanged with the fresh dissolvable solvent depending on the time, and can be reused as a solvent for the hydrogen reduction reaction of the present invention.

During the reduction and production, the desired aminodiphenyl ethers with high purity can be obtained by carrying out treatment by conventional methods such as distillation or crystallization as necessary.

The method of the present invention will be specifically explained below with reference to Examples.

Example 1 5-ami/-4'-nitrodiphenyl ether 50f1
250 y of water and 5 g of 5 chips pd/cO were charged into a 500 mJ r-1 crepe (made of SUS32) equipped with an induction stirrer. After pressurizing with hydrogen to 3LJkf/c111G,
The reduction reaction was carried out at a reaction temperature of 90°C. Since hydrogen was consumed (pressure decreased) as the reaction progressed, hydrogen was supplied from a hydrogen supply pipe connected to the autoclave, and the pressure was always maintained at 30 kf/ciiG. After 5 hours of reaction, the autoclave was cooled to 75° C. with a reed, opened, and the entire contents were transferred to a 500 m2 double-tube glass container. While the internal medicine in the glass container was maintained at 75° C. or higher, the oil phase (reduction product oil) was extracted from the cock at the bottom of the container to separate the product from the solvent. At this time, the catalyst contained in the oil phase was also removed using a suitable filter. The obtained crude 6,4'-diaminodiphenyl ether was purified by distillation under conditions of 2 mmHg and 200°C.

The obtained 5,4'-diaminodiphenyl ether was 42
．． 69, the yield based on 6-amino-4'-nitrodiphenyl ether was estimated at 8 mol.

Example 2 Crude 2,6'-diaminodiphenyl ether was obtained by the same method and operating conditions as in Example 1, except that the raw material was changed to 2-nitro-51-aminodiphenyl ether.

Next, this crude 2,6'-diaminodiphenyl ether was
Distilled under the conditions of mmHg, 21 JLl ℃2,
3'-diaminodiphenyl ether 41.5f was obtained.

The yield of this knitting based on the raw material was 95 moles.

Example 3 4-amino-4'-nitrodiphenyl ether 2511
1 suy of water and 5% I) d/C0,2y were charged into a 500 mJ autoclave (made of SUS32) equipped with an induction stirrer. After pressurizing with hydrogen to 40kf/c++tG for 7j, a reduction reaction was carried out at a reaction temperature of 190°C for 1 hour. Hydrogen, which was consumed as the reaction progressed, was replenished in a timely manner. Immediately after the reaction was completed, 250 ml of toluene was introduced under pressure. The autoclave was then cooled down to 5 aC, the autoclave was opened, the internal medicine was taken out, and the oil and aqueous phases were separated. After removing the catalyst, the oil phase was allowed to cool while stirring, and crystals were precipitated. The crystals a1s, 9-i of 4,4'-diaminodiphenyl ether obtained by filtering and dry recording the precipitated crystals are 4-amino-4
The yield based on '-nitrodiphenyl ether is 67
It was morchi.

Furthermore, 1.7 g of 4,4'-diaminodiphenyl ether was recovered from the TJ liquid.

Example 4.5 Diaminodiphenyl ether was obtained by the same method and operating conditions as in Example 6, except that the type of nitrodiphenyl ether used as a raw material was changed as shown in Table 1. The results in this case are shown in Table 1.

7/

Claims (1)

[Claims] In a method for producing a corresponding aminodiphenyl ether by reducing a nitro group to an amine group by contacting a nitrodiphenyl ether with hydrogen in the presence of a hydrogen reduction catalyst, the nitrodiphenyl ether is brought into contact with hydrogen under hydrogen reduction reaction conditions. In the presence of a S-soluble solvent for the nitrodiphenyl ethers and the solvent, the hydrogen reduction reaction is performed to form a heterogeneous mixture of the nitrodiphenyl ethers and the solvent to obtain a heterogeneous reaction product mixture, 1. A method for producing aminodiphenyl ethers, which comprises separating diamino diphenyl ethers by phase-separating the resulting mixture.