JPS59130841A - Preparation of phenylenediamine compound - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high purity, with simple separation process, by the catalytic hydrogenation of a nitroaniline compound in suspended state in a hydrocarbon which is non-solvent of the nitroaniline compound, its hydrogenated product and water, using a Raney-Ni catalyst. CONSTITUTION:A nitroaniline compound is suspended in a hydrocarbon which is essentially a non-solvent of the nitroaniline compound, a phenylenediamine compound which is the hydrogenated product of the nitroaniline compound, and water, (e.g. n-pentane, cyclohexane, benzene, etc.) or in a mixture of said hydrocarbon and water, if necessary in the presence of 0.001-1% of a surface active agent. The suspended nitroaniline compound is hydrogenated in the presence of a Raney-Ni catalyst preferably at 80-120 deg.C under 1-20kg/cm<2> to obtain phenylenediamine. The by-products produced by the hydrogenation reaction are dissolved in the hydrocarbon, and the objective compound can be separated in high purity by the simple liquid separation of the reaction liquid. It is not necessary to use expensive noble metal catalyst for the reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing phenylene diamines. More specifically, nitroanilines are suspended in nitroanilines, their hydrogenated products, phenylenediamines, and hydrocarbons that do not dissolve water, or in a mixture of these and water, if necessary in the presence of a surfactant. This invention relates to a method for producing phenylene diamines, which is characterized by catalytic hydrogenation using cloudy Raney nickel as a catalyst.

Phenylenediamines are important intermediates for dyes, pigments, pesticides, resins, etc. Methods for producing phenylenediamines by reducing nitroanilines include: ■ Reduction method using iron powder and acid ■ Reduction method using sodium sulfide ■ Method using catalytic hydrogenation. Among these methods, the method (2) uses a large amount of iron powder and is expensive to process the iron oxide after reduction, so it cannot be said to be an industrially advantageous method. In addition, method (2) has problems such as bad odor, lack of diamine purity, and contamination of waste water by sulfur compounds. Furthermore, the following drawbacks are also observed in the method (2) of catalytic hydrogenation of nitro compounds. That is, in order to remove the large reaction heat (approximately 132 Kcal per nitro group), a method is generally employed in which the nitro compound is diluted with an inert diluent and hydrogenated in a solution state. (METHODEN DER0RGA, NISCH
ENCl-IEMIE Vol. XI/1, 1957゜New Experimental Chemistry Course Vol.
Maruzen)] In this case, there is a method that uses a mixture of the hydrogenation product, that is, the amine compound, and the water produced by the reaction as a diluent, but since the amine compound is circulated and exposed to the hydrogenation reaction conditions repeatedly, side reaction products are generated. increases and tends to generate tar. Particularly when the amine is a phenylene diamine, the amount of side reaction products increases significantly, which is impractical. Also, although alcohols are often used as diluents, the produced amines dissolve well in alcohol-water systems, so after the reaction is complete, the alcohols must be almost completely removed from the reaction solution by distillation or other methods. It costs a lot of money. Another disadvantage of using alcohols as diluents is that the amines of the hydrogenation product react with the alcohols to by-produce undesirable N-alkyl compounds. As a method to improve these drawbacks, JP-A-51-26,82
In 6, a catalyst of a substance exhibiting a PTT value of 8 to 1 ρ in an aqueous solution is used as a diluent, using an aromatic hydrocarbon having a dielectric constant of about 2 to 3, which dissolves a nitro compound and a product amine compound but does not mix with water. A method for producing O-phenylenediamine from O-nitroaniline by catalytic hydrogenation has been proposed. In this case, one drawback has been improved by using alcohol as a diluent, but
Operations such as distillation are required to separate it from the aromatic hydrocarbon O-phenylenediamine.

Another improved method is disclosed in JP-A-51-86,404, in which the nitro compound is dissolved using catalytic hydrogen in the presence of a diluent that does not substantially dissolve the product amino compound and water. A method for producing amine compounds by chemical reaction has been proposed. There is an advantage that it is not necessary to separate the diluent from the reaction product by distillation after the reaction (liquid separation is performed).
The diluent (hydrocarbons) suitable for this purpose necessarily has a low dissolving power for nitro compounds, so a large amount is required to dissolve the nitro compound, resulting in a significant decrease in the volumetric yield of amine in the reaction vessel. There is. According to this patent, the preferred ratio of nitro compound to diluent is 1:
50 to 1:100.

As mentioned above, each method has its own drawbacks. ' The present inventors have investigated a method for producing phenylene diamines by catalytic hydrogenation of nitroanilines, which does not have the above drawbacks, and have developed a method for producing phenylene diamines that is industrially advantageous and has extremely high product purity. This discovery led to the present invention.

That is, nitroanilines, their hydrogenated products, phenylenediamines, and hydrocarbons that do not dissolve water, or a mixture of these and water, are used as diluents, and nitro compounds are added to the interface as necessary. This is a method in which 7-enylenediamine is obtained by suspending it in the presence of an activator and performing catalytic hydrogenation using Raney nickel as a catalyst. The method of the present invention is superior to conventional liquid phase methods because phenylene diamines are soluble in water but almost insoluble in hydrocarbon diluents, which allows easy phase separation after the reaction. This means that it can be separated from hydrocarbons without the need for distillation or other operations.

In this case, the used hydrocarbons can be recycled to the reaction system without requiring further treatment. Another advantage of the present invention is that nitroanilines are catalytically hydrogenated in a state suspended in a diluent, so the amount of diluent is smaller than in a method in which nitroanilines are hydrogenated in a state dissolved in a diluent. It is possible to improve the quality of charging nitroanilines to.

According to conventional knowledge, catalytic hydrogenation of nitro compounds in suspension using a diluent that makes the reaction solution two-phase is not possible.
The results of the present invention are surprising since it was thought that the reaction rate would be insufficient or the reaction would be interrupted. Another advantage of the present invention is that - a small amount of hydrogenated benzene nuclei or deaminated byproducts produced by the hydrogenation reaction easily dissolves in the hydrocarbon added as a diluent, and the resulting phenylenediamines Because of its extremely high purity.

be. Another advantage of the present invention is that inexpensive Raney nickel can be used as a catalyst, eliminating the need for a noble metal catalyst such as platinum or platinum.

Next, the method of the present invention will be explained in detail.

Examples of the hydrocarbon used as a diluent include saturated aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons optionally substituted with an alkyl group or a cycloalkyl group. Although the length of the carbon chain or the number of carbon atoms in the hydrocarbon does not really matter, since the nitroaniline is reacted in a suspended state, it is preferable to use a hydrocarbon that is liquid at room temperature to the hydrogenation reaction temperature. Next, specific examples of diluents will be given. n-pentane, isopentane, n-hexane, isohexane, n-1\butane as aliphatic hydrocarbons,
isooctane, n-octane, isooctane, 11-
Nonane, innonane, rhodecalin, isodecalin, 1
1-dodecane, isododecane, alicyclic hydrocarbons such as cyclo-\xane, methylcyclo-\xane, dimethylcyclohexane, ethylcyclo-\xane, decalin, alkyl-substituted decalin, aromatic hydrocarbons such as benzene, toluene , ethylbenzene, xylene, isopropylbenzene, tetralin, alkyl-substituted tetralin, and the like. Nitroanilines used as raw materials in the present invention include 0-1m-1p-nitroaniline, alkyl-substituted nitroaniline, halogen-substituted nitroaniline,
Examples include alkoxy-substituted nitroaniline.

Next, the method for preparing nitroanilines will be described.

Since nitroanilines are generally crystalline substances, they can be used either dry or as a wet cake; however, when stirring nitroanilines in hydrocarbons to form a slurry, static electricity buildup can be prevented. Therefore, it is more convenient to coexist water with a vcl of 0 to 30%.

In addition, it is convenient to add a surfactant to keep the nitroanilines in a stable suspension state and to improve the contact between the nitroanilines and the Raney nickel catalyst. Surfactants, anionic surfactants such as naphthalene sulfonic acid formalin condensate, sodium alkylbenzenesulfonate, Marcel soap, etc. are 0 for nitroanilines.
．． 001-1%. The concentration of the slurry of nitroanilines is not particularly limited as long as the resulting suspension has fluidity, but 20 to 60% is suitable.

As a catalyst, ordinary Raney nickel (for example, Yoken Fine Chemical NDT-90), which is prepared by developing a Raney alloy with caustic alkaline water, is used.

New Raney nickel or recovered Raney nickel may be used, but generally the recovered catalyst is replenished with a small amount of new catalyst and used repeatedly. When only new Raney nickel is used, it is preferable to stir it in an alcohol solvent such as alcohol, elathylene gellicol, or Shichiku Ruf for several hours to replace the water adhering to the catalyst surface. .

The amount of catalyst is generally 1 to 3 by weight based on the nitroaniline.
Use 0%. The reaction temperature is between 50 and 150°C, preferably between 80 and 120°C.

As the reaction pressure, any pressure of 1 kg/cr/l- or more can be selected, but 20 kp/m or less is sufficient.

Next, the general operation of the present invention is performed as follows, but is not limited thereto. Add a predetermined amount of aqueous pasty Raney nickel catalyst and optional surfactant to the autoclave.

A predetermined amount of nitroaniline suspended in a hydrocarbon or a mixture thereof with water is then added. After replacing the inside of the autoclave with nitrogen and then with hydrogen, the autoclave is pressurized with hydrogen to a predetermined pressure. Raise the temperature while stirring, for example l Q kg
Hydrogen is supplied under a /ad gauge hydrogen pressure while maintaining the temperature at 90° C. and stirring until hydrogen absorption disappears. There are other methods, such as: That is, a predetermined amount of Raney nickel catalyst, water, and surfactant are added to an autoclave. The inside of the autoclave is replaced with hydrogen, hydrogen pressure is applied, and the temperature is raised to, for example, 1Qky/cIit gauge and 90°C. While maintaining this pressure and temperature while stirring, the mixture is divided into portions and intermittently press-fitted. After the reaction is completed (after hydrogen absorption has stopped), the autoclave is cooled to an extent that the contents do not solidify, and stirring is stopped. After the catalyst is separated from the reaction solution (consisting of two phases) obtained in this way by sedimentation and p-filtration, an aqueous phase containing phenylenediamines and a hydrocarbon phase are separated. The separated catalyst and hydrocarbons are used for the next reaction. The phenylenediamine aqueous solution is cooled to precipitate and separate phenylenediamines, and if necessary, distilled to produce a product, or the water is distilled off from the phenylenediamine aqueous solution to produce a product.

Note that this is a continuous reaction in which nitroanilines left standing (in Raney nickel and diluent) are continuously charged into a reactor with reaction conditions maintained, while a two-phase liquid containing phenylenediamines and R-Ni is continuously taken out. Of course, it can also be adopted. Hereinafter, the present invention will be described in detail with reference to Examples.

Prepared by stirring in an autoclave 4.07 of Raney Ni Nokel, which was separated from methanol by decantation after stirring in methanol for 3 hours, 50 P of toluene/3 P of water/p-nitroaniline 721/0.21 of polyethylene glycol alkyl ether. Add the slurry. After replacing hydrogen, the temperature and pressure were increased to 90°C and reaction pressure I.
Qky. /cr/l While maintaining the gauge conditions and stirring, hydrogen is supplied at a rate that eliminates hydrogen absorption. It took 1 hour and 50 minutes to complete the reaction. After cooling to 80° C., the mixture is allowed to stand still to separate Raney nickel by precipitation. Remove the two-phase supernatant liquid and separate the toluene layer and the toluene layer in a heated separatory funnel.
The p-phenylenediamine aqueous solution layer was separated. p-
Yield of p-phenylenediamine obtained by distilling off water from an aqueous phenylenediamine solution4. ty (yield 96, 0
%), its GC analysis value (pure &)+! I was in charge of 99.90. Note that the p-phenylenediamine dissolved in the separated toluene phase was 1,5y-.

Example 2, Raney Nicke/l/4, Oy, xylem:y501i'/water30f/-/p-nitroaniline72P/polyethylene glycol alkyl used in autoclave K (Example 1) Add a slurry prepared by stirring 0.29-mL of ether. After hydrogen substitution, the temperature and pressure were increased, and hydrogen was supplied while stirring while maintaining the reaction temperature at 90°C and reaction pressure at 10'ky/crl gauge. It took 1 hour and 25 minutes to complete the reaction.

After cooling at 80°C, the mixture is allowed to stand still to separate Raney nickel by sedimentation. The supernatant liquid was taken out and separated into a xylene layer and a p-phenylenediamine aqueous solution layer. The yield of p-phenylenediamine obtained by distilling off water from the p-phenylenediamine aqueous solution was 54.7P (97.0% of theory), and its GC purity was 99.
．． The amount of p-phenylenediamine dissolved in the xylene phase was 87% and 1.4P.

Example 3.

After stirring for 3 hours in methanol in an autoclave, the methanol was separated by tecantation to give Taraney Nickel 4.0? , Schiff, lohexane 501/water 30g-/O
-Nitroaniline 7 2 f! -/Polyethylene glycol alkyl ether 0. 2? Add the slurry prepared by stirring. After hydrogen substitution, the temperature and pressure were increased, and while maintaining the reaction temperature at 90° C. and the reaction pressure at loky/d gauge, hydrogen was supplied while stirring until hydrogen absorption disappeared.

It took 2 hours and 15 minutes to complete the reaction. After cooling to 80° C., the mixture is allowed to stand still to separate Raney nickel by precipitation. The supernatant liquid was taken out and the cyclohexane layer and the 0-phenylenediamine aqueous solution layer were separated. O-phenylenediamine obtained by distilling water off from an aqueous solution of O-phenylenediamine is 53. Of! −(
The yield was 94.0%), and the GC purity was 9990%.

Example 4.

A slurry is prepared by stirring toluene 230 f/-/water to Oy-/p nitroaniline 33054/po IJ ethylene glycol alkyl ether 11 at room temperature.

Water 501 and Raney nickel 209- used in the catalytic hydrogenation for p-phenylenediamine synthesis were added to an autoclave, and after replacing with hydrogen, the temperature was raised with stirring and hydrogen pressure was applied to 90°C.
Let it be lOk1/cr/t gauge. While maintaining these conditions, the previously prepared slurry of p-nitroaniline was injected little by little. Pressing time of p-nitroaniline slurry,
The reaction time was 2 hours, and thereafter hydrogen was supplied while maintaining the above reaction conditions until hydrogen absorption ceased. Total hydrogen uptake time was 2 hours and 40 minutes. After cooling to 80° C., the mixture is allowed to stand still to separate Raney nickel by precipitation. The two-phase reaction product liquid was taken out and separated into a toluene layer and a p-phenylenediamine aqueous solution layer. Yield of p-phenylenediamine obtained by distilling off water from p-phenylenediamine aqueous solution: 249f# (yield: 9.6
．． 5%), GC purity l-! I was in charge of 99.93.

Patent Applicant Nippon Kayaku Co., Ltd. Procedural Amendment 1, Indication of Case 1982 Patent Application No. 4217 2, Title of Invention Process for Manufacturing Phenylenediamines 3, Person Making Amendment Relationship with Case Patent Applicant Tokyo Metropolitan Government Fujimi-chome 11-2, Chiyoda-ku (408)
Nippon Kayaku Co., Ltd. Representative Director and President Tsunekazu Sakano 4, Agent 6, Fujimi-11-chome-2, Chiyoda-ku, Tokyo, Number of inventions will not increase due to the amendment 7, Claims of the specification subject to the amendment and Column 8 for detailed description of the invention;
Contents of Amendment As shown in the attached sheet, Contents of Amendment 1: The scope of claims in the specification is amended as follows.

``2. Claims (1) Nitroanilines, their hydrogen products phenylenediamines, and the king of water. A process for producing phenylene diamines, characterized by suspending anilines in the presence of a surfactant if necessary and subjecting them to catalytic hydrogenation using Raneni Soquel as a catalyst.'' 2, 4 lines from the bottom of page 1 of the same. Insert the word ``substantially'' after the word ``the three parties.''

that's all

Claims (1)

[Claims] (1) Nitroanilines are added to a hydrocarbon that does not dissolve phenylenediamines, which are their hydrogenated products, and water, or to a mixture of these and water, if necessary, in the presence of a surfactant. A method for producing phenylene diamines, characterized by suspension and catalytic hydrogenation using Raney nickel as a catalyst.