KR0138789B1 - Production of aminodiphenylamine - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a method for preparing aminodiphenylamine, wherein aminodiphenylamine using nitroaniline as a hydrogen acceptor when reacting phenylenediamine and cyclohexanone in a sulfur-free polar solvent in the presence of a hydrogen transfer catalyst. It relates to a manufacturing method of.

Description

Method for preparing aminodiphenylamine

The present invention relates to an improved process for preparing aminodiphenylamine.

The aminodiphenylamine obtained according to the method of the present invention is an industrial chemical which is very important as a raw material for rubber chemicals and dyes.

As a method for producing 4-aminodiphenylamine, a method of reducing N-nitrosodiphenylamine obtained by nitrosation reaction of p-phenylenediamine with a potential (PB Reports 77764, 27-32), formanilide or acetanilide, Methods of reducing nitro groups by condensation reaction of halogennitrobenzene (J. Org. Chem 42 (10), 1786-90) and the like are known. As a method for producing 2-aminodiphenylamine, a potential reaction of an azo compound is known (J. Org. Chem 295 (1), 91-7, 1985). Moreover, reduction of 3-nitrodiphenylamine, etc. are known as a manufacturing method of 3-aminodiphenylamine. However, these methods cannot be considered industrially advantageous methods because they require complex reaction steps and require a large amount of special reagents and / or solvents and / or precise purification steps.

Similarly to the present invention, a method for preparing aminodiphenylamine by reacting cyclohexanone and phenylenediamine in the presence of a hydrogen transfer catalyst and a hydrogen acceptor is also known. According to this method, aminodiphenylamine is obtained by using α-methylstyrene as a hydrogen acceptor and reacting cyclohexanone with phenylenediamine in the presence of a palladium catalyst (Japanese Patent Laid-Open No. 82-58648). In this method, however, α-methylstyrene cannot be effectively used for the reaction other than as a hydrogen acceptor, and all phenylenediamine as a raw material must be supplied into the reaction system in the form of phenylenediamine. This reaction must be carried out under high temperature pressurization. Therefore, this method is not considered to be satisfactory as an industrial manufacturing method.

The present inventors earnestly examined to develop an industrially more advantageous manufacturing method than the conventional method, and as a result, phenylenediamine (hereinafter, referred to as sulfur-free polar solvent) in the presence of a hydrogen transition catalyst in a sulfur-free polar solvent By using nitroaniline (hereinafter referred to as NA) as a hydrogen acceptor when reacting cyclohexanone with cyclohexanone, aminodiphenylamine (hereinafter referred to as ADPA) can be obtained in high yield under very mild conditions, and also in the reaction system. It has been found that the PD generated from NA can be used as a raw material, and the present invention has been reached.

It is an object of the present invention to provide a process for preparing aminodiphenylamine which reacts phenylenediamine and cyclohexanone in the presence of a hydrogen transfer catalyst in a sulfur-free polar solvent while using nitroaniline as the hydrogen acceptor.

According to the process of the invention ADPA is obtained in high yield under very mild conditions. The PD generated from NA can also be used as a raw material in the reaction system and at the same time can be reused with the sulfur partial catalyst of PD.

It is important to use sulfur-free polar solvents in the process of the invention. Examples of sulfur-free polar solvents that can be used include N, N-dimethylformamide, N, N-dimethylacetamide; Tetramethylurea; Methyl isobutyl ketone, tetrahydrofuran, dioxane and 1,3-dimethylimidazolidinone; Glymes such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, phenols such as methyl salicylate and phenol, alkylphenols such as methyl phenol and 2,4,6-trimethyl phenol and 3- Alkoxy phenols, such as a methoxy phenol and 4-methoxy phenol, are included. These solvents may be used alone or in combination. In addition, sulfur-containing polar solvents such as dimethyl sulfoxide and sulfolane have a toxic effect on the hydrogen transfer catalyst and are therefore not preferable.

Known hydrogen transfer catalysts can also be used in the process of the invention. Specific examples include nickel / carrier catalysts supported on various carriers such as Raney nickel, reduced nickel or diatoms, alumina, pumice, silica gel, and acid clay; Cobalt catalysts such as Raney cobalt, reduced cobalt, cobalt and cobalt / carrier catalysts; Palladium catalysts such as palladium black, palladium oxide, colloidal palladium, palladium / carbon, palladium / barium sulfate and palladium / barium carbonate; Platinum catalysts such as platinum / carbon; Rhodium catalysts such as colloidal rhodium, rhodium / carbon and rhodium oxide; Platinum group catalysts such as ruthenium catalysts; Rhenium catalysts such as direnium hepoxide and rhenium / carbon; Copper chromate catalyst; Molybdenum oxide catalyst; Vanadium oxide catalyst; And tungsten oxide catalysts. It is preferable to use a palladium catalyst among these catalysts. Particularly preferred is the use of a palladium / carrier catalyst, in particular the use of palladium / carbon or palladium / alumina. The amount of these hydrogen transfer catalysts used is generally 0.001 to 1.0 gram atoms, preferably 0.002 to 0.2 gram atoms, as metal atoms per gram molecule of cyclohexanone.

According to the method of the present invention, a Schiff base is formed by condensation of PD and cyclohexanone, and then ADPA is produced by dehydrogenation. NA is used as the hydrogen acceptor generated at this time. In this way, NA is converted into PD in the reaction system, and ADPA is formed by reaction of PD with another raw material, cyclohexane.

At this time, 0.67 mole of NA per mole of the base can be converted to PD. Therefore, in order to fully utilize the hydrogen generated in the reaction system, it is sufficient that the molar ratio of NA / cyclohexanone reacts at 0.67. A large NA at this stage leads to a tendency of lowering the reaction rate, which is not beneficial. On the other hand, when the molar ratio of PD / cyclohexanone is too small, ADPA and cyclohexanone produced in the reaction system react more to produce N, N'-diphenylphenylenediamine (hereinafter referred to as N, N'-DPPA). There is a tendency. In order to avoid such drawbacks, it is preferable to react by adding 0.67 mol NA and at least 0.33 mol PD per mol of cyclohexanone from the beginning of the reaction. More preferably, the sum of NA and PD is made to react at least 1.4 mol, in particular at least 17 mol, per mol of cyclohexanone.

In the process of the present invention, all the raw materials can be collectively charged into the reaction vessel at the beginning of the reaction. However, it is important to react with cyclohexanone and NA dropwise simultaneously in a mixture of a hydrogen transfer catalyst, PD, and a sulfur-free polar solvent.

Of course, it is preferable to add these after dripping them. By doing in this way, the molar ratio of PD / cyclohexanone can always be maintained at a higher level in a reaction system, and the target object can be obtained with a high yield.

This reaction may also be carried out while separating water from the reaction mixture by azeotropic distillation with a solvent such as benzene, toluene or xylene to remove the water.

The reaction temperature may be selected in the range of 140 to 250 ° C, preferably in the range of 160 to 200 ° C.

ADPA thus produced is obtained by treating the reaction mixture after completion of the reaction by a conventional method such as distillation, crystals or extraction. For example, the reaction mixture is filtered upon completion of the reaction and the catalyst is separated. The recovered catalyst can be reused. The filtrate is concentrated to recover the solvent. ADPA remaining in the reaction vessel is optionally purified by distillation, crystals or the like, if necessary to be used as a raw material for the next reaction.

Hereinafter, the method of this invention is demonstrated concretely by an Example.

Example 1

3.03 g of 5% Pd / C (molar content: 50 wt%; manufactured by NE Camcatt), 64.0 g of N, N-dimethylacetamide, 7.21 in a 200 ml round bottom flask equipped with a separator, reflux condenser, thermometer, and stirrer. g (0.07 moles) of paraphenylenediamine (hereinafter referred to as PPD), 19.63 g (0.20 moles) of cyclohexanone (hereinafter referred to as CH) and 18.42 g (0.13 moles) of paranitroaniline (hereinafter PNA) ), And the stirring was continued for 5 hours while maintaining the internal temperature at 158-162 占 폚. During this period, benzene was charged and the resulting water was removed by azeotropic distillation. The azeotropic distilled water-benzene mixture was condensed in a reflux condenser and then separated by a separator. The reaction mixture was cooled to room temperature and 5% Pd / C was filtered off from the reaction mixture. The filtrate was analyzed by gas chromatography to obtain the following data.

CH conversion: 99.95 (mol% / CH)

Yield of p-ADPA: 49.87 (mol% / CH)

By-product of N, N'-p-DPPA: 36.50 (mol% / CH)

Recovery of undehydrogenated water: 3.26 (mol% / CH)

Example 2-4

The reaction was carried out in the same manner as in Example 1, except that the amount of PPD in Example 1 was replaced as shown in Table 1. The results are shown in Table 1.

Comparative Example 1

The reaction was carried out in the same manner as in Example 1 except that N, N'-dimethylacetamide was replaced with p-cymene in Example 1. The results are shown in Table 1.

TABLE 1

Example 5

3.03 g of 5% Pd / C (molar content: 50 wt%; manufactured by NE Camcat), 40.0 g of N, N'-dimethylacetate in a 200 ml round bottom flask equipped with a reflux condenser with a separator, a thermometer, a dropping device and a stirrer Amide, 7.21 g (0.07 mol) of PPD was charged. A mixed solution consisting of 19.63 g (0.20 mole) CH and 18.42 g (0.13 mole) PNA was prepared and loaded into the dropping apparatus. The temperature of the flask was increased to 160 ° C while stirring, and the solution was added dropwise to the dropping device over 6 hours while maintaining the internal temperature at 158 to 162 ° C. After completion of the dropping, the contents were stirred for 1 hour while maintaining the internal temperature of the flask within the above temperature range. During this period, benzene was charged and the resulting water was removed by azeotropic distillation. The azeotropic distilled water-benzene mixture was condensed in a reflux condenser and then separated by a separator. The reaction mixture was cooled to room temperature and 5% Pd / C was filtered off from the reaction mixture. The filtrate was analyzed by gas chromatography to obtain the following data.

CH conversion: 99.51 (mol% / CH)

Yield of p-ADPA: 54.00 (mol% / CH)

By-product of N, N'-p-DPPA: 36.65 (mol% / CH)

Recovery of undehydrogenated water: 9.72 (mol% / CH)

Example 6-7 and Comparative Example 2

The same procedure as in Example 1 except that the corresponding polar solvent (Examples 6 and 7) or nonpolar solvent (Comparative Example 2) shown in Table (2) was used instead of N, N'-dimethylacetamide in Example 5. The reaction was carried out by the method.

The results are shown in Table 2.

TABLE 2

Example 8-12

The reaction was carried out in the same manner as in Example 5 except that the amount of PPD in Example 5 was changed to set the (PPD + PNA) / CH ratio to the corresponding value shown in Table 3. The results are shown in Table 3.

TABLE 3

Example 13-15

In Example 5, PPD and PNA were replaced with metaphenylenediamine (hereinafter referred to as MPD) and metanitroaniline (hereinafter referred to as MNA), respectively, and the (MPD + MNA) / CH ratios are shown in (Table 4). The reaction was carried out in the same manner as in Example 5, except that it was set to a rising value. The results are shown in Table 4.

TABLE 4

Example 16

3.03 g 5% Pd / C (water content: 50 wt%, manufactured by NE Camcad), 40.0 g of triethylene glycol dimethyl ether and 24.04 in a 200 ml round bottom flask equipped with a reflux condenser, thermometer, dropping device and stirrer g (0.25 mol) of orthophenylenediamine was charged. A mixed solution containing 19.63 g (0.20 mol) of CH and 18.42 g (0.13 mol) of ortonitroaniline was prepared and charged into a dropping apparatus. The temperature of the flask was increased to 170 ° C. while stirring, and the solution was added dropwise with a dropping device over 15 hours while maintaining the internal temperature at 170 to 173 ° C. After completion of the dropping, the contents of the flask were stirred for 2 hours while maintaining the internal temperature within the above temperature range. During that time, the water produced by charging benzene was removed by azeotropic distillation. The azeotropic distilled water-benzene mixture was condensed with a reflux condenser and then separated with a separator. After cooling the reaction mixture to room temperature, 5% Pd / C was filtered off from the reaction mixture. The filtrate was analyzed by gas chromatography to obtain the following data.

CH conversion: 100 (mol% / CH)

Yield of o-ADPA: 63.8 (mol% / CH)

Recovery of undehydrogenated water: 35.8 (mol% / CH)

Claims (2)

A method for producing aminodiphenylamine comprising reacting phenylenediamine and cyclohexanone in the presence of a hydrogen transfer catalyst in a sulfur-free polar solvent using nitroaniline as a hydrogen acceptor. The method according to claim 1, wherein the reaction is carried out while dropping nitroaniline and cyclohexanone into a mixture of a hydrogen transfer catalyst, a phenylenediamine, and a sulfur-free polar solvent.