JPS58157749A - Production of high-purity 3,4'-diaminodiphenyl ether - Google Patents

Abstract

PURPOSE:High-purity 3,4'-dinitrodiphenyl ether, which is obtained from inexpensive and readily available raw materials, is hydrogenated to effect the reduction of nitro groups and dechlorination to give the titled compound used as an intermediate of industrial chemicals in high purity at low costs. CONSTITUTION:A nucleus-chlorinated 4-nitrodiphenyl ether of the formula (X is Cl, H) is nitrated to give a corresponding nucleus-chlorinated 3,4-dinitrodiphenyl ether (abbreviated to 3,4'-DNDPECl) or 5,4'-dinitrodiphenyl ether. Then, the product is subjected to hydrogenation to effect the conversion of nitro groups into amino ones and dechlorination on the ring-substituting chlorines, thus giving 3,4'-diaminodiphenyl ether. Since the intermediate, 3,4'-DEDPECl, is obtained under mild conditions with no contamination of by-products in high purity and high yield, it is no need of purification with advantage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 3,4'-diaminodiphenyl ether (hereinafter abbreviated as 3,4'-DADPE). More specifically, 4-nitrodiphenyl ether substituted with chlorine is nitrated, and 3
, 4'-dinitro diphenyl ether or 5,4'-
Dinitrodiphenyl ether (hereinafter referred to as 3.4'
The present invention relates to a method for producing 3,4'-DADPE by hydrogenation reaction of (abbreviated as -DNDPE-Cz), 2) 7-minization by reduction of R group, and dechlorination.

3,4'-DADPE is attracting attention as an industrial intermediate or as a raw material for aromatic polyamide fibers having excellent heat resistance and chemical resistance. However, when used as a polymeric monomer, it needs to be highly pure and inexpensive.

As a general method for producing diphenyl ethers, a method using the Ullmann reaction is known. That is, this is a method in which a phenoxyto anion is used as a nucleophilic reagent and reacts with an aromatic halogen compound in the presence of a catalyst such as copper or an inorganic copper salt. In the case of 3.4'-DADPE, m-nitrophenol or m-7 minophenol is condensed with p-nido p-halogenobenzene or p-7 minohalogenobenzene, and the substituent contains a nido l-group. The desired product can be obtained by further reduction. Although this method is relatively simple and has a good yield, it causes a decrease in purity due to the contamination of isomers of phenols and nido-p...logenobenzenes, and currently m-nitrophenol or m-7 Minophenol is a rather expensive raw material and K to produce cheap 3,4'-DADPE is an industrially unsuitable method. Also, from the perspective of cheap raw materials and weight gain,
p-2) p-phenol or p-7 minophenol, m-2) 1lff halogenobenzene or m-
There is also a known method for producing the desired product by condensing Amitsuba p-genobenzene and, if the substituent has a nitro group, further subjecting it to KIR. However, this process has a low condensation yield of about 50% and, like the above-mentioned method, has problems in terms of purity due to the contamination of isomers, and therefore cannot be used as an industrial method.

The present inventors have developed a highly pure and inexpensive 3.4'-DADP.
We conducted extensive research on the production method of E, added chlorine to diphenyl ether in advance, or obtained a diphenyl ether derivative having a mononitro group and a polychlorine group, and converted these into p-3.4'-DNDPE-ct. After making , the above purpose can be achieved by reducing the nitro group and dechlorinating it by hydrogenation reaction! l, 4'-DAD
We have discovered a method of manufacturing PE. According to the method of the present invention,
By adding chlorine to an appropriate position of diphenyl ether, it is possible to prevent nitro groups from being substituted at positions other than 3,4' during nidization.
．． A nitro group can be introduced only at the 4' position,
3,4'-DNDPE-C1 obtained in this way
A high-purity target product can be obtained by converting the high-purity product into 3,4'-DADPE through a hydrogenation reaction and a dechlorination reaction.

In the method of the present invention, as for the synthetic route of 3.4'-DNDPE-Ct, for example, as an industrially advantageous method, 2,4-dichlorophenol and 6,4-dichloronitrobenzene are condensed and then p-condensed. Then, the 5-position is selectively substituted with the 2) p group, and 2,4,2'-tricle-5,4'-dinito p-diphenyl ether is obtained in high yield and with high purity. 2,4-dichlorophenol can be easily obtained by chlorinating p-chlorophenol, and 6,4-dichloronitrobenzene can be obtained by p-4)
It can also be easily obtained by chlorination of pp-benzene. As condensation raw materials, 2.4,6-trifluorphenol is used instead of 2,4-dichlorophenol, 3,4-dichlorophenol is used instead of 3,4-dichlorophenol, and 3.4,6-)lichlornitro is used instead of benzene. In any combination using benzene, the corresponding 3, in which the 3 position is selectively substituted with the 2) p group by condensation, 2) += conversion,
4'-DNDPE-CL can be obtained. In this case, 2,4.6-)dichlorophenol can be easily obtained with high purity by chlorination of phenol, and 3.4.
6-) Liquid p-flunitrobenzene is a chlorinated product of the above-mentioned 3,4'-dichlornide p-benzene and can be carried out under the same reaction conditions. That is, the condensation reaction is performed by adding caustic alkali to N-
The reaction may be carried out at 140 to 150°C using a polar solvent such as methylpyrrolidone or dimethyl sulfoxide, but the reaction can be carried out at 200°C or lower even without a solvent. Although the following 2) support for p conversion can be carried out without a solvent, it is preferable to use a solvent in consideration of removal after the reaction, separation of waste acid, etc. As the solvent, carbon tetrachloride, 1,2-dichloro(6) ethane, etc. are used in an amount equal to 1 to 5 times the amount of the raw material.

2) As a plating agent, a commonly used mixed acid of nitric acid and sulfuric acid is used. Nitric acid is used in an amount of 1 to 15 mol based on the raw material, and sulfuric acid is used in an amount of 2 to 10 mol, preferably 4 to 8 mol based on the raw material. The temperature is 10 to 100°C, preferably 20 to 60°C. As such, particularly harsh conditions are not required,
High yield and high purity 3.4 with no contamination by coolants or by-products
'-DNDPE-Cz is obtained, and no purification of the product is required.

In the method of the present invention, in the step of producing 3,4'-DADPE by the hydrogenation reaction of 3,4'-DNDpE-Cz, raw materials are mixed into a solvent in a pressurized reaction vessel, and in addition to the metal catalyst, desalination Caustic alkali for 1-hydrogenation was added, hydrogen was injected under pressure, and the mixture was stirred vigorously to cause a reaction. In the case of solvent-free reaction, it is necessary to carry out the reaction at a high temperature higher than the melting point of the raw materials, and it is preferable to use a solvent in consideration of safety and complexity of depositing after the reaction. As the solvent, water or an aliphatic alcohol such as methyl alcohol, ethyl alcohol, propyl alcohol, or butyl fluorol, which has relatively good solubility with the raw material or product and is easy to recover, is used. The amount used should be at least the same amount or about 10 times the amount of the raw material.

Further, it is preferable to use a catalyst during the hydrogenation reaction, and examples of the catalyst include those commonly used in hydrogenation reactions, such as Raney nickel, platinum/carbon, palladium/carbon, and the like. These catalysts are added to the raw material from 1 to
Use 10%. 3,4'-DNDPE-C1 to 3,4
Since the conversion reaction to -DADPE requires chlorination as well, it is preferable to complete the dechlorination reaction by adding caustic alkali after or during the hydrogenation reaction. . By selecting the above-mentioned catalysts that are commonly used in hydrogenation reactions, it is possible to carry out some degree of dechlorination reaction during the hydrogenation reaction, but it is necessary to carry out the dechlorination reaction at a high temperature in order to complete the dechlorination reaction. It can be carried out at low temperature by adding caustic alkali.

The caustic alkali may be either an aqueous solution or a solid, but considering the amount of water in the reaction system, it is better to use 40% or more, which is equivalent to the amount of chlorine added to the raw materials. The reaction temperature is 2) p
The reduction of the groups is carried out at 10-40°C, but in the case of dechlorination higher temperatures of 40-120°C, preferably 50°C, are carried out.
~100°C is required. Too high a temperature is undesirable because it promotes the formation of tar and byproducts.

In this way, the hydrogenation reaction and dechlorination reaction are carried out, and when the hydrogen pressure in the reaction vessel stops decreasing, the reaction is stopped, the reaction mass is taken out, and the reaction mass is separated into the catalyst and reaction liquid by filtration. Distillation is performed to remove the solvent and water, followed by distillation under reduced pressure to obtain 3.4'-DADPE.

Next, the present invention will be explained in more detail with reference to Examples.

Note that % means weight %.

Example 1 After adding solid potassium hydroxide (4.5 JB, 0.08 mol), 3,4-dichlorni)pbenzene 15F (0
, 08 mol) and dimethyl sulfoxide (100 -) were added, and the mixture was reacted at 140°C for 3 hours. After the reaction is completed, the mixture is poured into water and extracted with benzene. Distill off benzene 2.4.
24 g (0,075 mol) of dinylether (2'-)riku p-ru 4'-ditop Schiff (9) was obtained.

Dissolve this in 50F 1,2-dichloroethane and
% nitric acid 6. o I (0,094 mol) and 98% sulfuric acid 45F (0.45 mol) were mixed to form a mixed acid, which was added dropwise over 10 minutes and then reacted at 60°C for 1 hour. After the reaction is completed, the organic phase and the waste acid phase are separated, and then 1,2-dichloroethane is distilled off from the organic phase, and 2.4. , 2'-trickle 5,
4'-dinito p diphenyl ether 26&(0,072
mole) was obtained. No impurities were observed in gas chromatography of this product. Next, mix this with 100% methyl alcohol and commercially available 5% palladium carbon 08.
After charging g into the autoclave, hydrogen was pressurized to 30゛0.
The mixture was stirred vigorously. After 2 hours, when hydrogen absorption stopped, 10.41 (0.26 mol,
After adding 1.2 times the equivalent amount) and pressurizing hydrogen again, the temperature was raised to 90°C and vigorously stirred. When hydrogen absorption stopped after 5 hours, the reaction was stopped and the reaction mass was taken out. The reaction mass was immediately K-filtered to separate the catalyst and then distilled to remove the solvent and water, followed by vacuum distillation (10) (260°C/10 mxHI) to obtain 1419 (
0.07 mol) of white crystals were obtained. The analysis result of this product by gas chromatography shows that there is no impurity in 3,4'
- It was DADPE.

Example 2 2.4.6-)dichlorophenol 15.8F (008
mol), 3.4.5-) instead of 15 g of 3.4-dichloronitrobenzene 18.1.
9 (0.08 mol), condensation nitration was carried out in the same manner as in Example 1. 6'-Pentacro zL
-3,4'-dinitro diphenyl ether 31.
l11 (0,072 mol) was obtained. Next, a hydrogenation reaction was carried out in the same manner as in Example 1. However, caustic soda is IS# (
0.40 mol, 1.2 times equivalent) was used. As a result, highly pure 3.4'-DADPEl 4 N (0, [17 mol)] was obtained.

Example 3 2,4-dichlorophenol in Example 1 was replaced with 2,4-dichlorophenol.
．． 6-) Dichlorophenol 15.8.9 (0,08
4.519 (0.08 mol) of potassium hydroxide was added to 2.4-dichlorophenol (0.08 mol), and f3,4-dichlornito-pbenzene 30I (0.16 mol) was added at 170°C. Allowed time to react. After the reaction is complete, unreacted 3,4-dicp-benze is distilled off to give 2.4
．． 26.5 # (0,075 mol) of 6.2'-tetrachloro-4'-ditop diphenyl ether was obtained. This was nitrated in the same manner as in Example 1, and 2,4.6.2'-tetrachloro-5,4'-dinitrodiphenyl ether 28
．． 7.9' (0,072 mol) was obtained.

Next, a hydrogenation reaction was carried out in the same manner as in Example 1.

However, 12.9j' (0.32 mol, 12 times equivalent) of caustic soda was used. As a result, highly pure 3.4'-DADP
El 4 # (0.07 mol) was obtained.

Example 4 2, 4.2: 26.5 N (0,075 mol) of 6'-tetracool-4'-ditop diphenyl ether is dissolved in charcoal tetrachloride 50II followed by 98% nitric acid 7.2 F
(0,113 mol) and 98% sulfuric acid 6Z511 ([1,6
75 mol) to form a mixed acid and dropwise dropwise over 10 minutes.
The reaction was carried out at 0°C for 1 hour. This edge was processed in the same manner as in Example 1 and 2.4.2? 28.71 (0,072 mol) of 6'-natochlor-5,4'-dinitop diphenyl ether was obtained.

Next, instead of the 5% palladium/carbon in Example 1, 12.9 g (01
Highly purified 3.4'-DADPEl 4.9
(0.07 mol) was obtained.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd. (13)

Claims (1)

[Claims] 1. A corresponding compound obtained by nitration reaction of a nuclear chlorine-substituted 4-2)P diphenyl ether compound which shows the structural formula of general formula (4), and X is hydrogen or chlorine. 3,4'-dinitrodiphenyl ether compound having a nuclear salt substituent,
or a high-purity 3.4/-diamino which is obtained from a 5.4'-dinitrodiphenyl ether compound by a hydrogenation reaction that converts a nitro group into a corresponding 7mino group and a dechlorination reaction of nuclear-substituted chlorine. Method for producing diphenyl ether. 2. The method according to claim 1, wherein Raney nickel, platinum carbon, or palladium carbon is used as a catalyst for the hydrogenation reaction. 3. The method according to claim 1, wherein water or an aliphatic alcohol is used alone or as a mixture as a solvent for the hydrogenation reaction. 4. The method according to claim 1, in which caustic alkali is used in an amount equivalent to or more than chlorine in the dechlorination reaction. 5. The reaction temperature of hydrogenation reaction and dechlorination reaction was set to 10"
The method according to claim 1, which is carried out at a temperature of 0°C or higher and 120°C or lower.