JPH11222467A - Production of diarylamines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful as a raw material for rubber chemical, medicine, dye, etc. by using an arylamine as a raw material and a solid acid catalyst such as Y type zeolite or the like under pressure in a liquid phase. SOLUTION: Arylamines, preferably arylamines of formula I and formula II (R1 to R10 are each H, a 1-12C alkyl, a 1-12C alkoxy, phenyl or the like) (e.g. aniline, toluidine, cumidine or the like) are reacted by using Y type zeolite and/or USY type zeolite as a solid acid catalyst under pressure in a liquid phase preferably by adding water at 330-360 deg.C under 10-40 kg/cm<2> G, fractionating the unreacted arylamines from the reaction product and separating a high- boiling by-product as a residue to give the objective compound (preferably a compound of formula III). The acid point of the zeolite catalyst is preferably H type or NH4 type. The shape of the zeolite catalyst is preferably granule or a molded shape of tablet form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing diarylamines such as diphenylamine, which are raw materials for rubber drugs, medicines, dyes and the like. More specifically, starting from an arylamine such as aniline in the presence of a solid acid catalyst,
The present invention relates to a method for producing diarylamines such as diphenylamine under a pressurized liquid phase.

[0002]

2. Description of the Related Art Conventionally, as a method for producing diphenylamine using aniline as a starting material, hydrochloric acid, P ₂ O ₅ ,
Pressurized liquid phase method using PCl ₃ , AlCl ₃ , BF ₃ or NH ₄ BF ₄ as a catalyst (for example, JP-A-51-1386)
No. 28, JP-A-53-40697), and a fixed-bed gas phase method using alumina or the like, for example, acid-treated γ-alumina (for example, JP-A-61-103857, JP-B-3 No. 16943), and a method for producing diphenylamine by using a synthetic solid acid catalyst as a catalyst and reacting it under a fixed-bed pressurized liquid phase (for example, Japanese Patent Publication No.
2-15585, JP-A-54-135728) and the like.

[0003]

However, the pressurized liquid phase method has the drawback that the catalyst is corrosive, so that a highly corrosion-resistant container is required, and that the separation and recovery of the catalyst are difficult. . In addition, the fixed bed gas phase method has disadvantages in that the reactor becomes large and equipment cost increases, and that tar-based by-products generated during the reaction adhere to the catalyst surface and the activity of the catalyst decreases. On the other hand, in the fixed bed pressurized liquid phase method, even when a synthetic solid acid catalyst conventionally disclosed in the above-mentioned patents, for example, a silica-alumina-based catalyst which is considered to have high reaction activity, is used, its conversion rate is low. Is not sufficient, so that it is necessary to collect and recycle a large amount of the raw material aniline, that is, it has a drawback such as low productivity.

[0004]

Under such circumstances, the present inventors have made intensive studies on the pressurized liquid phase method using a solid acid catalyst, and as a result, have found that Y-type zeolite and / or When a USY-type zeolite is used, it has been found that the reaction activity is greatly improved, and the conversion of arylamine to diarylamine is significantly improved, and the present invention has been completed.

That is, the present invention relates to a process for producing a diarylamine from an arylamine as a raw material in the presence of a solid acid catalyst under a pressurized liquid phase, wherein a Y-type zeolite and / or a USY-type zeolite are used as a solid acid catalyst. To provide a method for producing diarylamines, characterized by using

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method of the present invention will be specifically described below. In carrying out the method of the present invention, it is essential to use Y-type zeolite or USY-type zeolite as a solid acid catalyst. Various types of zeolites are known in addition to Y-type zeolites. For example, β-type, L-type, MFI-type, SAPO-type, mordenite-type and the like are known as typical ones. In the method of the present invention, Y-type zeolite or USY-type zeolite may be mainly used as a catalyst. It does not exclude the combination with these.

[0007] Zeolite has acid sites as solid acid catalysts, and these acid sites are preferably H type or NH ₄ type. Of course, as long as the applied zeolite is in a range having a function as a solid acid catalyst, it may contain Na type, K type and the like. In addition, as long as the conversion is not significantly reduced as a solid acid catalyst, the zeolite constituent A
Of course, it is possible to use zeolite in which a part of l or Si is substituted by other various metals. These Y-type zeolite catalyst and / or USY-type zeolite catalyst may be those obtained by a generally known production method, and the production method is not particularly limited. The shape of the zeolite catalyst at the time of use is not particularly limited, and it can be used in various shapes such as powder, granules, tablets, etc. .

In the present invention, the arylamines to be used are not particularly limited, but the following general formulas [1] and [2] wherein R _{1 to} R ₁₀ are the same or different. May be hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons,
Phenyl, hydroxy, amino, nitro or 1 to 1 carbon atoms
Selected from the group consisting of alkyls having 1 to 12 carbon atoms substituted with 12 alkoxy, hydroxy or phenyl), and the raw material arylamine is reacted in the presence of a solid acid catalyst comprising the above-mentioned Y-type zeolite. By reacting, a diarylamine represented by the following general formula [3] (the symbols and conditions in the formula are the same as in the above general formulas [1] and [2]) can be obtained.

[0009]

The above-mentioned general formulas [1] and [2] as raw materials
Specific examples of the arylamine represented by aniline,
Examples include toluidine, ethylaniline, cumidine, butylaniline, anisidine, xylidine, fluoroaniline, bromoaniline, iodoaniline, fluorodimethylaniline and the like, with aniline, toluidine, cumidine and xylidine being particularly preferred. In the reaction, general formulas [1] and [2] may of course be the same, for example, only aniline.

In carrying out the present reaction method, the raw material arylamine can be reacted as it is or by adding water. Regarding the addition of water during the reaction, silica-
Japanese Patent Application Laid-Open No. 54-135728 discloses that a composite oxide catalyst such as alumina has an effect of improving the conversion rate. However, apart from the degree of the effect, Y-type zeolite and / or Alternatively, in the present system using a USY-type zeolite, the starting arylamines may be reacted in the presence of water. In this case, the same formulation as in JP-A-54-135728 can be applied to the method and amount of water to be added.

This reaction is carried out in a temperature range of 300 to 400 ° C.
It is desirably carried out under a temperature condition of 330 to 360 ° C. When the temperature is lower than 300 ° C., the reaction proceeds slowly, which is not suitable for practical use. On the other hand, if the temperature is 400 ° C. or higher, a large amount of by-products is generated, and when a low-boiling raw material such as aniline is used as the raw material, a high pressure is required to maintain the liquid, which is not preferable.

The pressure in the practice of the present invention may be any pressure that can release the generated ammonia and maintain the liquid phase of the reaction phase at the above reaction temperature. This pressure increases in proportion to the reaction temperature and decreases as the mole fraction of arylamines in the reaction phase decreases as the reaction proceeds. In addition, this pressure may generally correspond to the saturated vapor pressure of the arylamine at the reaction temperature. For example, in the case of aniline, it is usually 10 to 40 kg at the above-mentioned reaction temperature.
/ Cm ² G.

In the method of the present invention, after the reaction, unreacted arylamines are fractionated from the reaction product, and then the desired diarylamines can be easily obtained by separating high-boiling by-products as residues. it can. When water is added during the reaction, most of the water is recovered at the same time as the arylamines during the fractionation of the unreacted arylamines, so that the fractionated arylamines are appropriately adjusted in water content. Can be reused.

The process of the present invention can be carried out by either a batch process or a continuous process. However, industrially, a continuous process in which the raw materials, arylamines, and water are continuously supplied and the reactants are continuously withdrawn while controlling the pressure. Is advantageous in terms of work efficiency.

[0016]

According to the present invention described in detail above, in producing a diarylamine from an arylamine as a raw material under a pressurized liquid phase, a Y-type zeolite and / or a USY-type zeolite are used as a solid acid catalyst. By using it, it is possible to greatly improve its productivity, and its industrial value is extremely large.

[0017]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 A 500 ml stainless steel autoclave was charged with 50 g of the catalyst powder shown in Table 1 (commercially available zeolite), 200 g of aniline and 2 g of water, and the air in the autoclave was replaced with nitrogen. The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, the obtained reaction product was cooled, taken out of the autoclave, the catalyst was filtered, and the concentration of diphenylamine (abbreviated as DPA) in the reaction solution was analyzed using a gas chromatograph. Table 1 shows the results.
The commercially available zeolite catalysts used are the following products. HY zeolite (Si / Al = 5.6): manufactured by JGC Universal Co., Ltd. (trade name: LZ-15) HY zeolite (Si / Al = 2.8): manufactured by N-Chemcat (trade name: HY) H-USY zeolite (Si / Al = 5.2): manufactured by JGC Universal (trade name: LZY-74) H-USY zeolite (Si / Al = 5.9): manufactured by JGC Universal (trade name: LZY) -84) H-USY zeolite (Si / Al = 6.0): N
H-USY zeolite (Si / Al = 10.0) manufactured by E-Chemcat (trade name: USY): manufactured by N-Echemcat (trade name: USY)

[0019]

[Table 1]

Comparative Example 1 The procedure of Example 1 was repeated, except that the catalysts shown in Table 2 were used as the catalyst. Table 2 shows the results. The silica alumina catalyst and zeolite used are the following products. Silica alumina (Si / Al = 6.5): manufactured by Nikki Chemical Co., Ltd. (trade name: N633L) Silica alumina (Si / Al = 2.6): manufactured by Nikki Chemical Co., Ltd. (trade name: N632NH) H-β type zeolite ( (Si / Al = 25.0): JGC Universal Corporation (trade name BETA)

[0021]

[Table 2]

Claims (2)

[Claims] 1. A process for producing a diarylamine from an arylamine as a raw material under a pressurized liquid phase in the presence of a solid acid catalyst, wherein Y-type zeolite and / or
Alternatively, a method for producing diarylamines, comprising using a USY zeolite. 2. A diarylamine represented by the following general formula [3] is produced by reacting an arylamine represented by the following general formula [1] with an arylamine represented by the following general formula [2]. The method according to claim 1, wherein [Wherein, R _{1 to} R ₁₀ may be the same or different, and each represents hydrogen, alkyl having 1 to 12 carbons, alkoxy, phenyl, hydroxy, amino, nitro or carbon having 1 to 12 carbons. Alkoxy of formulas 1 to 12,
C1-C1 substituted by hydroxy or phenyl
Selected from the group consisting of 2 alkyls)