JPH0517417A - Production of aromatic amine compound - Google Patents

Abstract

PURPOSE:To obtain an aromatic amino compound useful as pharmaceuticals, agricultural chemicals, dyes, pigments or their intermediates from an aromatic nitro compound in high selectivity and efficiency and high catalytic activity while suppressing side reactions such as water gas shift reaction. CONSTITUTION:An aromatic amine compound is produced from an aromatic nitro compound (excluding nitroanthraquinones) by using carbon monoxide and water in the presence of a homogeneous catalyst composed of a ruthenium compound and a solvent. The solvent used in the above reaction is a lower alcohol, glyme or a lower alkyl ketone, especially selected from methanol, ethanol, diethylene glycol and dimethyl ether and the reaction is carried out in the presence of triethylamine. There is little progress of side reactions such as water gas shift reaction in spite of high catalyst activity and the nitro group is exclusively reduced in high selectivity to get the objective compound in high efficiency.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the use of carbon monoxide and water in the presence of a homogeneous catalyst consisting of a ruthenium compound and a solvent to convert aromatic nitro compounds (excluding nitroanthraquinones) to aromatic amines. A method of making a compound. Aromatic amine compounds such as aniline are industrially important compounds as medicines, agricultural chemicals, dyes, pigments and intermediates thereof.

[0002]

2. Description of the Related Art As a method for producing an aromatic amine compound from an aromatic nitro compound in a carbon monoxide / water system using a ruthenium catalyst, for example, Journal of American Chemical Society (J. Am. Che
m. Soc. 1978, 100 , 3969) discloses an example in which the reduction reaction of nitrobenzene was carried out in the presence of a ruthenium catalyst in a mixed solvent of tetrahydrofuran-trimethylamine aqueous solution.

[0003]

In the above-mentioned tetrahydrofuran-trimethylamine aqueous solution catalyst system, a large amount of hydrogen more than the produced aniline is produced as a by-product in the reaction system. There was a problem that carbon oxide was also consumed. About this, American Chemical Society Symposium Series (ACS Symp. Ser., 152 , 32)
5 (1981)), the reason is that the so-called water gas shift reaction activity, which produces hydrogen and carbon dioxide from water and carbon monoxide, is specifically high in a ruthenium catalyst system to which trimethylamine is added. To do.

Further, in this conventional technique, it is difficult to say that the activity of the catalyst is sufficient, and the catalyst concentration is increased,
It was necessary to react at high temperature and high pressure for a long time.

[0005]

In view of such circumstances, the present inventors have used carbon monoxide and water in the presence of a homogeneous catalyst composed of a ruthenium compound and a solvent in a liquid phase to produce an aromatic nitro compound. As a result of diligent research on a method for producing an aromatic amine compound from a compound (excluding nitroanthraquinones), a specific solvent selected from lower alcohols, glyme and lower alkyl ketones was used as a solvent, and a specific amine was further prepared. By coexisting, it was found that only the nitro group is selectively reduced, and even though its catalytic activity is high, a side reaction such as a water gas shift reaction does not proceed. Has been completed.

That is, the present invention uses carbon monoxide (hereinafter referred to as CO) and water in the presence of a homogeneous catalyst composed of a ruthenium compound and a solvent to remove an aromatic nitro compound (excluding nitroanthraquinones). In the method for producing an aromatic amine compound from (4), a solvent selected from lower alcohols, glyme and lower alkyl ketones is used as a solvent, and triethylamine is allowed to coexist with the solvent. It is a thing.

The present invention will be described in detail below. In the reaction of the present invention, CO and water are used as hydrogen sources.

The aromatic nitro compound used in the present invention is a compound having at least one nitro group in the aromatic ring. Examples of the aromatic ring include hydrocarbon aromatic rings such as benzene, naphthalene and anthracene, and heteroaromatic rings such as pyridine and quinoline. Further, a substituent such as an alkyl group, a halogen group, an amino group, a hydroxyl group, a carbonyl group, an alkoxy group, a cyano group or a sulfone group may be bonded to these aromatic nitro compounds in addition to the nitro group.

Examples of commonly used aromatic nitro compounds include nitrobenzene, o-nitrotoluene, m-
Nitrotoluene, p-nitrotoluene, 2-nitro-p
-Xylene, o-chloronitrobenzene, m-chloronitrobenzene, p-chloronitrobenzene, p-cyanonitrobenzene, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-dinitrobenzene, m
-Dinitrobenzene, p-dinitrobenzene, 2,4-
Dinitrotoluene, o-nitrophenol, m-nitrophenol, p-nitrophenol, o-nitroanisole, m-nitroanisole, p-nitroanisole,
α-nitronaphthalene, β-nitronaphthalene, 2'-
Nitroacetophenone, 3'-nitroacetophenone,
3-nitrobenzophenone, 4-nitrobenzophenone, 4-nitroimidazole, o-nitrobenzonitrile, m-nitrobenzonitrile, p-nitrobenzonitrile, o-nitrobenzenesulfonic acid, m-nitrobenzenesulfonic acid, p-nitrobenzenesulfonic acid , O-
Nitrobenzenesulfonic acid amide, m-nitrobenzenesulfonic acid amide, p-nitrobenzenesulfonic acid amide, o- (β-hydroxyethylsulfonyl) nitrobenzene, m- (β-hydroxyethylsulfonyl) nitrobenzene, p- (β-hydroxyethylsulfonyl)
Examples include nitrobenzene.

The catalyst used in the present invention is a ruthenium compound, preferably a complex having a carbonyl ligand, a compound forming a ruthenium carbonyl complex in the reaction system, and a compound forming a complex with phosphine or phosphite. .. For example, carbonyl compounds, acetylacetonate salts, carboxylates, oxides, hydroxides, halides, nitrates, phosphates and other salts and coordination compounds are examples of compounds that form carbonyl complexes under the reaction conditions. Can be mentioned.

Specifically, as this catalyst, Ru ₃ (CO) ₁₂ , H
₄ Ru ₄ (CO) ₁₂ , [RuCl ₂ (COD)] _n , [RuCl ₂ (CO) ₃ ] ₂ , Ru (CO) ₅ , R
uO ₂ , RuCl ₃ , RuBr ₃ , RuI ₃ , Ru (acac) ₃ , Ru (NO) (NO ₃ ) ₃ , Ru (N
O) Cl ₃ , H ₃ Ru (SO ₃ ) ₂ OH, etc., and PPh ₃ and P (OPh) ₃
And the like.

Among these, Ru ₃ (CO) ₁₂ , [RuCl ₂ (COD)] _n , [Ru
Cl ₂ (CO) ₃ ] ₂ , RuO ₂ , Ru (acac) ₃ , RuCl ₂ (CO) ₂ (PPh ₃ ) _{2 and the} like are preferable.

The amount of the catalyst used in the present invention varies depending on the reaction conditions and the like, but is usually about 10 ^-1 to 10 ^-5 mol per mol of the substrate.

The homogeneous catalyst used in the present invention means a catalyst in which the ruthenium compound as a catalyst is partially or wholly dissolved in a solvent.

Examples of the solvent used in the present invention include lower alcohol solvents such as methanol, ethanol, isopropyl alcohol, normal propyl alcohol, normal butyl alcohol, isobutyl alcohol, normal pentyl alcohol and isoamyl alcohol, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether. , Tetraethylene glycol dimethyl ether, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monoethyl ether acetate, and other grime-based solvents, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Examples of lower alkyl ketone solvents include . Among these, methanol, ethanol, isopropyl alcohol, normal butyl alcohol, isoamyl alcohol, and diethylene glycol dimethyl ether are preferable. More preferred are methanol, ethanol and diethylene glycol dimethyl ether.

The triethylamine used in the present invention is usually used in an amount of 0.01 to 500 times by mole, preferably 0.01 to 300 times by mole, based on the amount of the catalytic metal atom.

The reaction temperature of the present invention is usually 0 to 250 ° C., more preferably 100 to 200 ° C., and the activity is improved by increasing the reaction temperature. Further, the reaction time of the present invention is not particularly limited. C used in the present invention
The pressure of O is not particularly limited, but may be usually 1 to 100 atm or higher.

[0018]

As described in detail above, according to the present invention,
It is possible to efficiently produce a corresponding aromatic amine compound by highly selectively reducing only a nitro group and having a remarkable catalytic activity, while hardly causing a side reaction such as a water gas shift reaction to proceed.

[0019]

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.

Example 1 A magnetic stir type autoclave made of stainless steel with an internal volume of 50 cc was charged with Ru ₃ (CO) ₁₂ (0.005 mmol) and methanol (5 m
l), water (2 ml), triethylamine (1.5 mmol),
And nitrobenzene (about 10 mmol) were added, and CO pressure was 2
The mixture was stirred at 0 kg / cm ² and 150 ° C. and reacted for 2 hours. The reaction product was quantitatively analyzed by gas chromatography, and its identification was performed by comparing retention times of gas chromatograms and using GC-MS. The same analytical method was used in the following examples and comparative examples. Further, the following total turnover number (TN) was used as an index showing the activity of the catalyst. Total turnover number (TN) = amount of aniline produced (mm
ol) / catalyst amount (mmol) When analyzed after the reaction, the reaction product was only aniline, and no other by-products were present.
The TN was 1986. In addition, less than 0.3% (0.11 mmol) of hydrogen was produced in the gas phase after the reaction.

Example 2 The reaction was carried out under the same conditions as in Example 1 except that the methanol used in Example 1 was isoamyl alcohol. As a result of analysis after the reaction was completed, the reaction product was only aniline,
There were no other by-products. The TN was 1872. In addition, less than 0.3% (0.11 mmol) of hydrogen was produced in the gas phase after the reaction.

Comparative Example 1 The same autoclave used in Example 1 was charged with Ru ₃ (C
O) ₁₂ (0.005 mmol), tetrahydrofuran (6.
5 ml), 25% trimethylamine aqueous solution (3.5 g) and nitrobenzene (10 mmol) were added, and CO pressure was 20 kg.
The reaction was performed at 150 ° C./cm ^{2 for} 2 hours. As a result of analysis after completion of the reaction, the reaction product was only aniline. The TN was 1682. In addition, 42% (34.8 mmol) of hydrogen was produced in the gas phase after the reaction.

Example 3 The reaction was carried out under the same conditions as in Example 1 except that 0.005 mmol of Ru ₃ (CO) ₁₂ was changed to 0.003 mmol and methanol was changed to ethanol. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. T
N was 2415. Further, in the gas phase after the reaction, 0.
Less than 3% hydrogen was produced.

Example 4 The reaction was carried out under the same conditions as in Example 3 except that the ethanol used in Example 3 was isoamyl alcohol. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. The TN was 2281. In addition, less than 0.3% of hydrogen was produced in the gas phase after the reaction.

Example 5 The reaction was carried out under the same conditions as in Example 3 except that 5 ml of ethanol in Example 3 was changed to 15 ml of methanol and 2 ml of water was changed to 5 ml of water. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. T
N was 2505. Further, in the gas phase after the reaction, 0.
Less than 3% hydrogen was produced.

Example 6 The reaction was carried out under the same conditions as in Example 3 except that 5 ml of ethanol in Example 3 was changed to 15 ml of ethanol and 2 ml of water was changed to 5 ml of water. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. T
N was 2505. Further, in the gas phase after the reaction, 0.
Less than 3% hydrogen was produced.

Example 7 The reaction was carried out under the same conditions as in Example 3 except that 5 ml of ethanol in Example 3 was replaced with 15 ml of isopropyl alcohol and 2 ml of water was replaced with 5 ml of water. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. The TN was 2135. In addition, less than 0.3% of hydrogen was produced in the gas phase after the reaction.

Example 8 5 ml of methanol in Example 1 was changed to 5 ml of diethylene glycol dimethyl ether, and a reaction temperature of 150 ° C. was 18
The reaction was performed under the same conditions as in Example 1 except that the temperature was 0 ° C. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. The TN was 2058, and the yield was 99% or more. In addition, less than 0.3% of hydrogen was produced in the gas phase after the reaction.

Example 9 In a magnetic stirring type autoclave made of stainless steel with an internal volume of 50 cc, Ru ₃ (CO) ₁₂ (0.002 mmol), diethylene glycol dimethyl ether (10 ml), water (4 ml), triethylamine (1.5 mmol), and nitrobenzene were added. (2
1 mmol) was added, and the mixture was stirred at 180 ° C. under a CO pressure of 60 kg / cm ² , and reacted for 5 hours. As a result of analysis after completion of the reaction, the reaction product was only aniline, and no other by-products were present. The TN was 10500, and the yield was 99% or more. In addition, less than 0.3% of hydrogen was produced in the gas phase after the reaction.

Examples 10 to 14 Ru ₃ (CO) ₁₂ (0.01 mmol), diethylene glycol dimethyl ether (15 ml), water (5 ml) and Table 1 were placed in a stainless steel magnetic stirring type autoclave having an internal volume of 50 cc.
Add the nitro compound (5mmol) shown in, and CO pressure 20kg / c
The mixture was stirred at m ² and 150 ° C. and reacted for 3 hours. The results are shown in Table 1.

[0031]

[Table 1]

Comparative Example 2 The reaction was carried out under the same conditions as in Example 10 except that the same amount of acetophenone was used instead of o-chloronitrobenzene and the reaction time was 3 hours for 2 hours. As a result of analysis after completion of the reaction, no reaction product was confirmed and only acetophenone was recovered.

Comparative Example 3 The reaction was carried out under the same conditions as in Example 10 except that the same amount of benzaldehyde was used instead of o-chloronitrobenzene and the reaction time of 3 hours was changed to 2 hours. As a result of analysis after completion of the reaction, most of benzaldehyde was recovered (benzyl alcohol 0.08% or less).

Comparative Example 4 Example 1 was repeated except that the same amount of styrene was used instead of o-chloronitrobenzene, and the reaction time of 3 hours was 2 hours.
The reaction was performed under the same conditions as 0. As a result of analysis after completion of the reaction, most of styrene was recovered (ethylbenzene 0.3% or less).

Comparative Example 5 Except that the same amount of phenylacetylene was used instead of o-chloronitrobenzene and the reaction time of 3 hours was 2 hours.
The reaction was carried out under the same conditions as in Example 10. As a result of analysis after completion of the reaction, most of phenylacetylene was recovered (styrene and ethylbenzene total 1.3% or less).

Claims (1)

Claims: 1. An aromatic nitro compound (excluding nitroanthraquinones) is converted from an aromatic amine by using carbon monoxide and water in the presence of a homogeneous catalyst composed of a ruthenium compound and a solvent. A method for producing an aromatic amine compound, which comprises using a solvent selected from a lower alcohol, glyme and a lower alkyl ketone as a solvent and coexisting with triethylamine.