JP2014005217A - Method for producing aromatic amine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an aromatic amine compound by efficiently reacting an aromatic nitro compound under relatively mild conditions.SOLUTION: An aromatic amine compound is produced under mild conditions by bringing an aromatic nitro compound into contact with hydrogen micro bubbles having a fine bubble diameter of 50 μm or less to reduce mass transfer limitations in a reaction and thereby increasing a rate of the reaction.

Description

  The present invention relates to a method for producing an aromatic amine compound by hydrogen reduction of an aromatic nitro compound.

Aromatic amine compounds are useful as raw materials for pharmaceuticals, agricultural chemicals, dyes, polymer materials and the like. As a method for producing an aromatic amine by reducing an aromatic nitro compound, a catalytic hydrogenation method using a metal catalyst such as platinum, palladium or Raney nickel is known (Non-patent Document 1).
Hydrogen reduction reactions of aromatic nitro compounds are widely practiced on an industrial scale. In carrying out these reactions, vigorous stirring is required to bring the gas phase-liquid phase interface into contact under a hydrogen atmosphere. Moreover, when performing these reactions, in order to raise reaction rate, it is necessary to make it react under high temperature and a high pressure. The ideal reaction condition is to increase the interface without mechanical stirring under normal temperature and normal pressure conditions, but in this case, the reaction rate is remarkably reduced, which is disadvantageous in productivity. is there.

In most cases, the hydrogen reduction reaction is a heterogeneous method. In designing a hydrogen reduction facility, it must be decided whether to operate the reaction method in a liquid phase method or a gas phase method. The former provides feasibility in small equipment, but often has to be used at high operating pressures because rate determinants usually result in low solubility of hydrogen in the organic liquid phase. This means that the cost of construction and operation is an economically important factor in the overall process.
As a method for increasing the reaction rate in the hydrogen reduction of aromatic nitro group compounds, it is effective to reduce the restriction of mass transfer by reducing the contact bubbles in order to increase the contact frequency between gas and liquid. Although it is a means, although the utilization to a chemical reaction is suggested by the method (for example, patent document 1) using a fine bubble, it does not show about the concrete contribution to the reaction rate rise.

  Patent Document 2 discloses a method for producing cyclohexane by introducing a system including a high shear mechanical device in the hydrogenation reaction of benzene and introducing hydrogen gas bubbles having an average bubble diameter of less than 100 nm. The hydrogen reduction of aromatic nitro groups is not shown, and the reaction is carried out under conditions of high reaction temperature and pressure.

JP 2004-121962 A Japanese translation of PCT publication 2010-53882

Practical Catalytic Hydrogenation, 168, John Wiley & Sons Inc. Published, 1971

  An object of the present invention is to efficiently produce an aromatic amine compound by reducing an aromatic nitro compound under relatively mild conditions.

  That is, the present invention is a method for producing an aromatic amine compound, wherein an aromatic nitro compound is brought into contact with hydrogen microbubbles having an average diameter of 50 μm or less.

  According to the present invention, the aromatic nitro compound is brought into contact with fine hydrogen microbubbles having a bubble diameter of 50 μm or less, thereby reducing the limitation of mass transfer in the reaction and increasing the reaction rate. Aromatic amine compounds can be produced.

The apparatus diagram of the manufacturing method of the aromatic amine compound which concerns on one form used for implementation of this invention The apparatus figure of the manufacturing method of the aromatic amine compound which concerns on another form used for implementation of this invention

(Aromatic nitro compounds)
An aromatic nitro compound is a compound obtained by substituting a nitro group (—NO ₂ ) for an aromatic compound.
Examples of the aromatic compound in the aromatic nitro compound include benzene, condensed aromatic compounds, and heteroaromatic compounds. Examples of the condensed aromatic compound include naphthalene, anthracene, and phenanthrene. Heteroaromatics include pyridine, quinoline, benzothiophene, diphenyl ether and the like.
The number of carbon atoms of the aromatic compound is preferably 6-20, more preferably 6-15.
Aromatic nitro compounds can have one or more substituents in addition to the reduced nitro group. Examples of these substituents include alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, aryl groups having 6 to 20 carbon atoms, arylalkyl groups having 6 to 20 carbon atoms, amino groups, Examples thereof include a hydroxyl group, a cyano group, an aldehyde group, a carboxyl group, a halogen atom, a haloalkyl group having 1 to 10 carbon atoms, and a hydroxyalkyl group having 1 to 10 carbon atoms.

  As an alkyl group having 1 to 10 carbon atoms as a substituent, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group Etc. Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, and t-butoxy group. . A phenyl group etc. are mentioned as a C6-C20 aryl group. Examples of the arylalkyl group having 6 to 20 carbon atoms include a benzyl group and a phenethyl group.

  Examples of the halogen atom include F, Cl, Br, I and the like. Examples of the haloalkyl group having 1 to 10 carbon atoms include a trifluoromethyl group and 1-chloroethyl. Examples of the hydroxyalkyl group having 1 to 10 carbon atoms include a hydroxymethyl group and a 1-hydroxyethyl group. The position of these substituents may be any position on the aromatic ring, and is not limited to the number of substituted aromatic nitro groups to be reduced.

  As the aromatic nitro compound, a compound represented by the following formula (1) is preferable.

  In the formula, m is an integer of 1 to 5. n is an integer of 0-5. In the formula, Ar is an aromatic ring represented by the following formula.

  R is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, an amino group, a hydroxyl group, and a cyano group. Aldehyde group, carboxyl group, halogen atom, haloalkyl group having 1 to 10 carbon atoms, hydroxyalkyl group having 1 to 10 carbon atoms, and the like.

  As an alkyl group having 1 to 10 carbon atoms as a substituent, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group Etc. Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, and t-butoxy group. . A phenyl group etc. are mentioned as a C6-C20 aryl group. Examples of the arylalkyl group having 6 to 20 carbon atoms include a benzyl group and a phenethyl group.

  Examples of the halogen atom include F, Cl, Br, I and the like. Examples of the haloalkyl group having 1 to 10 carbon atoms include a trifluoromethyl group and 1-chloroethyl. Examples of the hydroxyalkyl group having 1 to 10 carbon atoms include a hydroxymethyl group and a 1-hydroxyethyl group.

  As the aromatic nitro compound, a compound represented by the following formula (1-1) or the following formula (1-2) is preferable.

(In formula (1-1), R and n are the same as in formula (1).)

(In formula (1-2), R and n are the same as in formula (1).)
As the aromatic nitro compound represented by the above formula (1), nitrobenzene, nitroanisole, nitroaniline, nitrobenzoic acid, nitrotoluene, nitroethylbenzene, nitrophenol, nitrobenzonitrile, nitrobenzaldehyde, nitrobenzyl alcohol, nitrochloroaniline , Dichloronitroaniline, trichloronitroaniline, nitrochlorophenol, dichloronitrophenol, trichloronitrophenol, nitrothiophenol, nitrotoluidine, dinitrobenzene, dinitroanisole, dinitrotoluene, dinitrophenol, dinitrothiophenol, dinitrobenzaldehyde, dinitrobenzoic acid , Nitronaphthalene, nitronaphthol, nitroaminonaphthalene, nitronaphthylcarboxylic acid, Trochloronaphthalene, dinitronaphthalene, dinitronaphthol, dinitroaminonaphthalene, dinitronaphthylcarboxylic acid, dinitrochloronaphthalene, dinitrodichloronaphthalene, aminonitrodiphenyl ether, nitrochlorodiphenyl ether, hydroxynitrodiphenyl ether, nitrocarboxydiphenyl ether, dinitrodiphenyl ether, nitroanthracene, nitro Mention may be made of hydroxyanthracene, nitroanthracene carboxylic acid, dinitroanthracene, dinitrohydroxyanthracene or dinitroanthracene carboxylic acid.

(Aromatic amine compound)
An aromatic amine compound is a compound in which an aromatic group is substituted with an amine group (—NH ₂ ). The aromatic compound in the aromatic amine compound is the same as the aromatic compound in the aforementioned aromatic nitro compound. Examples of the aromatic amine include aromatic amino compounds in which one or two or more nitro groups in the above-listed compounds such as aniline, toluidine, trimethylaniline, and anisidine are converted into amino groups.

(Hydrogen microbubble)
The present invention is characterized in that hydrogen microbubbles having an average diameter of 50 μm or less are used in contact with an aromatic nitro compound as a raw material. When the average diameter of the hydrogen microbubbles is larger than 50 μm, the hydrogen microbubbles expand due to the pressure drop in the hydrogen microbubbles as the hydrogen microbubbles rise in the liquid. As a result, the specific surface area (surface area per unit weight) of the hydrogen microbubbles increases, so that the reduction reaction promoting effect is lowered.
The average diameter of the hydrogen microbubbles is preferably 5 nm to 50 μm, more preferably 10 nm to 500 nm, still more preferably 50 to 400 nm, and most preferably 100 to 300 nm. The diameter of the hydrogen microbubble can be measured by NanoSight LM-10 (manufactured by United Kingdom NanoSight) that observes light scattering of micro-brown motion of the microbubble. Further, in order to increase the specific surface area of the hydrogen microbubbles, the number of hydrogen microbubbles per unit volume in the liquid to be brought into contact with the aromatic nitro compound (hereinafter referred to as “total bubble number”) is also important. The total number of bubbles per mL of liquid is preferably 10 ⁵ or more, preferably 10 ⁶ to 10 ⁹ , more preferably 10 ⁷ to 10 ¹⁰ . The average diameter and the total number of bubbles of these hydrogen microbubbles can be adjusted and set according to the model number and generation conditions of a hydrogen microbubble generator to be described later, depending on the viscosity of the solvent used, the relative dielectric constant, and the like.
In the region of the bubble diameter and the total number of bubbles, the rate of increase in the solvent is small and it can remain in the reaction system for a long period of time, so that the restriction of mass transfer in the hydrogen reduction reaction can be reduced. Even if the bubble size is small, the reaction rate is not adversely affected, but the degree of saturation of hydrogen into the solvent (including the supersaturated state) is limited, so that it is economically inefficient even if it is too small. Become. Further, the total number of bubbles can be generated according to the setting conditions of the generator, and the more the microbubbles can exist stably in the reaction with the nitro compound, the better.

  Hydrogen microbubbles can be manufactured using a microbubble manufacturing apparatus that uses pressure dissolution-shearing force as a generation principle. As a specific example of such a microbubble manufacturing apparatus, there is an apparatus described in JP-A-2006-159187. When this apparatus is used, hydrogen is sucked in from the outside by using the negative pressure when the diaphragm pump is started, and a gas-liquid mixture of hydrogen and the reaction solvent is made. In this gas-liquid mixture, hydrogen may be in a state of being dissolved in a solvent in a saturated state (including a supersaturated state), which is considered to be almost similar to a state in which a gas is dissolved in a solvent under a pressurized state. Therefore, this process is called pressure dissolution. This gas-liquid mixture is sent to a static mixer and further stirred and mixed with the static mixer to make a fine gas-liquid mixture. The stationary mixer is composed of an upstream screw part and a downstream cutter part, and the screw part is composed of a cylindrical main body, a partition bar arranged in an axial center part of the main body, and a main body and a partition bar. The cutter part is comprised from the cylindrical main body and the some protrusion distribute | arranged to the internal peripheral surface of the main body. The gas-liquid mixture becomes a swirling flow when passing through the screw portion, and this swirling flow can collide with the protrusion of the cutter portion and continuously generate hydrogen microbubbles of 50 μm or less by a shearing force. When a microbubble generator having such a pressure dissolution-shearing force as a generation principle is used, there is an effect that microbubbles of 50 μm or less can be obtained at a high concentration and monodisperse.

(catalyst)
As the hydrogen reduction catalyst, a noble metal catalyst such as platinum or palladium is preferably used. These may be supported on a carrier such as carbon or alumina.
Preferably, it is preferable to use a palladium carbon (Pd / C) catalyst or a palladium alumina (Pd / Al ₂ O ₃ ) catalyst with 1 to 20% by weight of carbon as a support, and a more preferable amount to be supported is 5 to 15%. %. Moreover, it is preferable to use it so that it may become 0.1-10 mol% in conversion of a palladium atom with respect to the aromatic nitro compound to reduce | restor, More preferably, it is 0.2-5 mol%.
(Reaction conditions and equipment)
The reaction temperature is preferably not higher than the boiling point of the solvent used, but is preferably −10 to 80 ° C., more preferably 5 to 60 ° C., and still more preferably 10 to 50 ° C. The reaction pressure is 50 to 500 kPa, preferably 100 to 200 kPa, more preferably normal pressure (101.3 kPa). Thus, in the present invention, an aromatic amine compound can be obtained from an aromatic nitro compound under mild conditions such as −10 to 100 ° C. and normal pressure to 200 kPa by using hydrogen microbubbles having an average diameter of 50 μm or less. .

The reaction was carried out using an apparatus as shown in FIG. 1 or FIG. That is, the aromatic nitro compound solution 8 placed in the vial 9 passes through the filter 7 and is introduced into the motor 2 along the direction of the arrow 6. On the other hand, the flow rate of the hydrogen gas is adjusted by the gas flow rate control valve 5, the flow rate is measured by the flow meter 3, and then introduced into the aromatic nitro compound solution 8, and gas-liquid mixing is performed in the aromatic nitro compound solution 8. The body is manufactured. Specifically, the gas-liquid mixture containing the aromatic nitro compound and hydrogen passes through the pump and the static mixer 1 connected to the motor 2 and further passes through the internal part of the discharge pressure adjusting screw 4. A fine gas-liquid mixture (a solution of an aromatic nitro compound containing hydrogen microbubbles) is made by stirring and mixing in a static mixer. Thereafter, in the apparatus shown in FIG. 1, the catalyst is introduced into the catalyst fixing rod along the direction of the arrow 6. The inside of the catalyst fixing cage is kept at a constant temperature, and the hydrogen reduction reaction proceeds. After the hydrogen reduction reaction proceeds, it is returned again into the vial 9 as a mixed solution 8 of the aromatic nitro compound and aromatic amino compound. On the other hand, in the apparatus shown in FIG. 2, the catalyst is suspended in the mixed solution 8 of the aromatic nitro compound and the aromatic amino compound, and the hydrogen reduction reaction proceeds in the vial. Needless to say, it is preferable that the vial bottle in which the hydrogen reduction reaction proceeds is maintained at a constant temperature as necessary.
(Measurement of hydrogen bubble average diameter and total number of bubbles)
The measurement conditions are shown below.
Solvent volume (mL): 200
Sampling volume (mL): 1.5
Stage sampling amount (mL): 0.5
Camera Level: 16
Detection Threshold: 5
Bubbling time (min): 20
Water temperature (° C.): Room temperature (20 to 26 ° C.)
Measurement procedure:
Microbubbles are generated in a solvent (200 mL) for 20 minutes with a microbubble generator, and after 20 minutes, a sample solution (0.5 mL) is injected into a stage attached to NanoSight LM-10 (manufactured by NanoSight, England) Diameter and total bubble count were measured.

Hereinafter, the content of the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
In the following examples and comparative examples, experiments were conducted as follows unless otherwise specified. Methanol (80 mL) degassed for 10 minutes and an aromatic nitro compound (20 mmol, 1 eq) were added to a 100 mL vial to make a uniform solution. A catalyst-fixed tube with a filter is filled with palladium carbon (Pd / C 10% [Pd supported amount 10% by weight], 106 mg, Pd 0.1 mmol, 0.5 mol%), or equivalent amount of Pd / Al ₂ O _3. Then, microbubbles were generated at a hydrogen flow rate of 0.5 mL / min and an outlet pressure of 0 to 0.6 MPa to carry out a reduction reaction.

[Example 1]
Hydrogen microbubbles have a hydrogen flow rate of 5 mL / min, a gas-liquid mixed fluid amount of 120 mL / min, and a pressure of 0.0 MPa-0.6 MPa using a microbubble manufacturing apparatus having the configuration described in Japanese Patent Application Laid-Open No. 2006-159187. As described above, hydrogen microbubbles were generated by using the pressure dissolution-shearing force adjusted by the air inlet. The above reaction was performed with an apparatus as shown in FIG. 1, and the average diameter and the total number of bubbles of hydrogen microbubbles were measured with NanoLight LM-10 (manufactured by NanoSight, England).
The conversion was calculated by analyzing the composition by gas chromatography (GC2010 manufactured by SHIMADZU). The substrate nitro compound is a commercially available nitrobenzene (SAJ, purity 99.0%), the reaction solvent is reagent methanol (Kanto Chemical Co., purity 99%), dimethylformamide [DMF] (SAJ, 99% purity) was used. A more detailed experimental procedure is given below.

Methanol (80 mL, 1953 mmol, 0.25 M) degassed for 10 minutes and nitrobenzene (2.1 mL, 20 mmol, 1 eq) were added to a 100 mL vial and stirred with a magnetic stirrer to give a homogeneous solution. Palladium carbon (Pd / C 10% [Pd loading 10% by weight]) (106 mg, 0.1 mmol, 0.5 mol%) was charged into a catalyst-fixed cage with a filter and maintained at 30 ° C. On the other hand, using the above-mentioned microbubble generator (MA3FS type manufactured by Asp Co., Ltd., pumping capacity 120 to 150 mL), the gas flow rate control valve is adjusted and the average hydrogen flow rate is 5 mL / min (maximum 6 mL / min, minimum 4 mL / min The discharge pressure adjusting screw was adjusted so that the maximum outlet pressure was 0.6 MPa and the minimum outlet pressure was 0.0 MPa to generate hydrogen microbubbles, and a reduction reaction was performed. After reacting for 3 hours, filtration through silica (SiO ₂ , 2 g, ethyl acetate [AcOEt]) and confirmation by gas chromatography gave aniline. The conversion was 69%. Detailed production conditions and results are shown in Table 1.

[Example 2]
When the reaction was carried out under the same conditions except that the reaction time was 5 hours in Example 1, the conversion rate from nitrobenzene to aniline was 91%. Detailed production conditions and results are shown in Table 1.

[Example 3]
DMF (73 mL, 943 mmol) degassed for 10 minutes and 3-amino-4'-nitrodiphenyl ether (ANPE) (7.4 mL of 38 wt% DMF solution, 20 mmol, 1 eq) were added to a 100 mL vial, and the mixture was stirred with a magnetic stirrer. A homogeneous solution was obtained. Thereafter, hydrogen microbubbles were generated by the same operation as in Example 1 to perform a reduction reaction. After reacting for 4 hours, filtration through silica (SiO ₂ , 2 g, AcOEt) and confirmation by gas chromatography gave 3,4′-diaminodiphenyl ether. The conversion was 65%. Detailed production conditions and results are shown in Table 1.

[Example 4]
When the reaction was carried out under the same conditions except that the reaction time was 6 hours in Example 3, the conversion rate from ANPE to 3,4'-diaminodiphenyl ether was 91%. Detailed production conditions and results are shown in Table 1.

[Example 5]
In the apparatus shown in FIG. 2, DMF (36 mL, 477 mmol) degassed for 10 minutes in a 100 mL vial and 3-amino-4′-nitrodiphenyl ether (ANPE) (3.7 mL of 38 wt% DMF solution, 10 mmol, 1 eq). The mixture was stirred with a magnetic stirrer to obtain a homogeneous solution, and palladium on alumina (Pd 0.5%) (8.5 g, 0.4 mmol, 4 mol%) was added to a 100 mL vial and kept at 30 ° C. On the other hand, using the micro-bubble generator (Asp Co., Ltd. MA5S type, pump capacity 300 mL), adjust the gas flow rate adjustment valve and adjust the discharge pressure adjustment screw so that the hydrogen flow rate becomes 5 mL / min on average. Hydrogen microbubbles were generated such that the maximum outlet pressure was 0.1 MPa or more, and a reduction reaction was performed. In addition, the average diameter of hydrogen microbubbles and the total number of bubbles were measured with NanoSight LM-10 (manufactured by NanoSight, England).
After reacting for 4 hours, filtration through silica (SiO ₂ , 2 g, ethyl acetate [AcOEt]) and confirmation by gas chromatography gave 3,4′-diaminodiphenyl ether. The conversion rate was 100%. Detailed production conditions and results are shown in Table 1.

[Example 6]
In Example 5, the reaction was carried out under the same conditions as in Example 5 except that MA3FS type was used as the microbubble generator and the reaction time was 7 hours. As a result, the conversion rate from ANPE to 3,4'-diaminodiphenyl ether was 100%. Detailed production conditions and results are shown in Table 1.

[Comparative Example 1]
After adding methanol (80 mL), nitrobenzene (2.1 mL, 20 mmol, 1 eq), palladium carbon (Pd 10%) (106 mg, 0.1 mmol, 0.5 mol%) deaerated for 10 minutes to a 100 mL vial, and stirring at 1000 rpm Connected to a hydrogen balloon. After stirring for 3 hours at 1000 rpm, filtration through silica (SiO ₂ , 2 g, AcOEt) and confirmation by gas chromatography gave aniline. The conversion was 16%. Detailed production conditions and results are shown in Table 2. The reaction performed by connecting to the hydrogen balloon used in this comparative example is a balloon inflated with hydrogen gas up to several times the volume of the vial so that the mouth of the vial is sealed, and the hydrogen gas is This represents that the reaction is performed in a hydrogen gas atmosphere in a state where no substitution is performed. Therefore, hydrogen microbubbles are not generated.

[Comparative Example 2]
When the reaction was conducted under the same conditions except that the reaction time was 5 hours in Comparative Example 1, the conversion rate from nitrobenzene to aniline was 28%. Detailed production conditions and results are shown in Table 2.

[Comparative Example 3]
After adding methanol (80 mL), nitrobenzene (2.1 mL, 20 mmol, 1 eq), palladium carbon (Pd 10%) (106 mg, 0.1 mmol, 0.5 mol%) deaerated for 10 minutes to a 100 mL vial, and stirring at 1000 rpm Then, hydrogen gas was bubbled through a glass filter. After stirring for 3 hours at 1000 rpm, filtration through silica (SiO ₂ , 2 g, AcOEt) and confirmation by gas chromatography gave aniline. The conversion rate was 21%. Detailed production conditions and results are shown in Table 2.

[Comparative Example 4]
When the reaction was conducted under the same conditions except that the reaction time was 5 hours in Comparative Example 3, the conversion rate from nitrobenzene to aniline was 31%. Detailed production conditions and results are shown in Table 2.

[Comparative Example 5]
DMF (73 mL) and ANPE (38 wt% DMF solution 7.4 mL, 7.4 mL, 20 mmol, 1 eq), palladium carbon (Pd 10%) (106 mg, 0.1 mmol, 0.5 mol%) degassed in a 100 mL vial for 10 minutes ) Was added and stirred at 1000 rpm, and hydrogen gas was bubbled through a glass filter. After stirring at 1000 rpm, filtration through silica (SiO ₂ , 2 g, AcOEt) and confirmation by gas chromatography gave 3,4′-diaminodiphenyl ether. The conversion was 43%. Detailed production conditions and results are shown in Table 2.

[Comparative Example 6]
When the reaction was carried out under the same conditions except that the reaction time was 6 hours in Example 5, the conversion rate from ANPE to 3,4'-diaminodiphenyl ether was 58%. Detailed production conditions and results are shown in Table 2.

  As shown in Tables 1 and 2, according to the present invention, by using hydrogen microbubbles having an average diameter of 50 μm or less, aromatic nitro compounds are fragranced under mild conditions such as normal pressure and near room temperature. Group amine compounds can be produced in high yield.

1 Pump and static mixer (including microbubble generator including 2 to 5 (FIG. 1 is MA3FS type, FIG. 2 is MA5S type))
2 Motor (stored inside)
3 Flow meter 4 Discharge pressure adjusting screw 5 Gas flow rate adjusting valve 6 Flow direction of reaction solution 7 Filter 8 Aromatic nitro compound solution (before reaction start) or mixed solution of aromatic nitro compound and aromatic amine compound (reaction start) rear)
9 Vial 10 Catalyst

Claims (3)

A method for producing an aromatic amine compound, comprising contacting an aromatic nitro compound with hydrogen microbubbles having an average diameter of 50 μm or less. The manufacturing method according to claim 1, wherein the hydrogen microbubbles are generated using a pressure dissolution-shearing force. The method according to claim 1 or 2, wherein the aromatic nitro compound is a compound represented by the following formula (1).
(In the formula, m is an integer of 1 to 5. n is an integer of 0 to 5. Ar is an aromatic ring represented by the following formula.
R is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, an amino group, a hydroxyl group, and a cyano group. Aldehyde group, carboxyl group, halogen atom, haloalkyl group having 1 to 10 carbon atoms, and hydroxyalkyl group having 1 to 10 carbon atoms. )