JP3177351B2 - Method for producing tris (diarylamino) benzenes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound of the formula (3)

[0002]

Embedded image (Wherein R and R ′ represent hydrogen or a lower alkyl group). The present invention relates to an improved method for producing tris (diarylamino) benzenes represented by the formula:

[0003] Tris (diarylamino) benzenes obtained by the method of the present invention are extremely useful compounds as resin additives, electrophotosensitive materials, electroluminescent materials and the like.

[0004]

2. Description of the Related Art A method for producing tris (diarylamino) benzenes includes the following.
In the presence of copper metal powder or a copper halide catalyst and a suitable basic substance (potassium carbonate, potassium hydroxide, etc.), trihalobenzene and diphenylamines are added in a hydrocarbon solvent.
Ullmann reaction is known, such as a method of reacting at 0 to 200 ° C. and a method of reacting tris (arylamino) benzenes and aryl halides under the same conditions.

For example, tribromobenzene and 3 moles of diphenylamine are dissolved in a diphenyl ether solvent in the presence of a catalytic amount of cuprous iodide and potassium carbonate as a base in diphenyl ether solvent.
Reaction at 9 ° C for 24 hours, tris (diphenylamino)
A method for obtaining benzene with a yield of 10.3% (K. Yoshi)
zawa, el al, J.M. Am. Chem. So
c. , 114, 5994 (1992). ) And a large excess of tris (phenylamino) benzene with a large excess of iodide benzene or toluene iodide in a decalin solvent at 160 ° C. for 6 hours in the presence of excess metal copper powder and potassium hydroxide to give tris (diphenylamino). ) Benzene, tris (N-4-methylphenyl-N-phenylamino) benzene, tris (N-3-methylphenyl-N-phenylamino) benzene and tris (N-2-methylphenyl-N-phenylamino) benzene 63%, 4
6%, 35% and 22% yield (W.Ish
Ikawa, et al, Mol. Cryst. Li
q. Cryst. , 211, 431 (1992). ) Is disclosed.

However, in the conventional methods based on the Ullmann reaction, the selectivity and the yield are low, the step of removing the product is complicated, and it is necessary to use an excessive amount of an aryl halide and a basic substance. In addition, it was difficult to say that the production method was industrially satisfactory due to the fact that the catalyst could not be recovered.

[0007]

Means for Achieving the Object The present inventors have intensively studied an industrially advantageous method for improving these points, and as a result, have found that tris (arylamino) amine is present in the presence of a hydrogen transfer catalyst.
By heating and reacting benzenes and cyclohexanone, an enamine intermediate is produced by a condensation reaction between tris (arylamino) benzenes and cyclohexanone,
Subsequently, this dehydrogenation reaction occurs, and tris (diarylamino) benzenes can be produced. Furthermore, if phenols corresponding to the raw material cyclohexanone are present in the reaction system, they are consumed in the condensation reaction simultaneously with the dehydrogenation reaction. It is found that the amount of phenols corresponding to the cyclohexanone is easily reduced to form cyclohexanone, condensed with tris (arylamino) benzenes and dehydrogenated to produce the desired tris (diarylamino) benzenes. The invention has been reached.

That is, the method of the present invention comprises the steps of:
A process for producing tris (diarylamino) benzenes, which comprises heating and reacting tris (arylamino) benzenes with cyclohexanones.
At that time, a phenol corresponding to the cyclohexanone used in the reaction is present in the reaction system, so that the cyclohexanone is used in a catalytic amount or charged excessively without coexisting the cyclohexanone in the reaction system from the beginning. Phenols are partially converted to the corresponding cyclohexanone under pressure of hydrogen in tris (arylamino) benzenes, and then the phenols and tris (arylamino) benzenes are heated and reacted. This is a method for producing tris (diarylamino) benzenes.

The process of the present invention not only gives satisfactory results in terms of selectivity and yield of the target compound, but also, after filtering the reaction mixture to separate the catalyst, recrystallization directly from the filtrate, Alternatively, since the target compound can be taken out by recrystallization after concentrating the filtrate, there is an advantage that the taking out step is simple and the catalyst can be recovered.

The tris (arylamino) benzenes used as raw materials in the method of the present invention include tris (phenylamino) benzene, tris (2-methylphenylamino) benzene, tris (3-methylphenylamino) benzene, Tris (arylamino) benzenes having an alkyl substituent on the nucleus, such as tris (4-methylphenylamino) benzene.

These tris (arylamino) benzenes are dehydrated and condensed by heating phloroglysine and the corresponding aniline in the presence of an iodine catalyst (NP Buu-).
Hoi, J. et al. Chem. Soc. , 4346 (195
2). ) Can be obtained in good yield.

Examples of the cyclohexanone include cyclohexanone, methylcyclohexanone, ethylcyclohexanone, isopropylcyclohexanone, butylcyclohexanone and the like. There is no particular problem as long as the amount of the tris (arylamino) benzenes is at least 3 mol times.

As the hydrogen transfer catalyst used in the method of the present invention, any known hydrogen transfer catalyst may be used. Specifically, Raney nickel, reduced nickel or nickel supported catalyst, Raney cobalt, reduced cobalt or cobalt supported catalyst, Raney copper , Reduced copper or copper carrier catalyst, noble metal catalyst of Group VIII of the periodic table or a catalyst in which the noble metal is supported on carbon, alumina, barium carbonate, etc., rhenium catalyst such as rhenium-carbon, copper-chromium oxide Catalysts and the like can be mentioned. Among these catalysts, palladium is preferable, and a palladium catalyst supported on a carrier such as palladium-carbon, palladium-alumina and palladium-magnesium oxide is particularly preferable. The amount of the metal used is usually 0.001 to 0.05 g atom, preferably 0.005 to 0.030 g atom as a metal atom with respect to tris (arylamino) benzenes.

In the method of the present invention, the dehydration condensation reaction between tris (arylamino) benzenes and cyclohexanones is a rate-determining step. Therefore, it is advantageous to carry out the reaction while removing water. A suitable method is to separate water from the reaction mixture by azeotropic distillation using a solvent such as toluene or xylene. In order to further increase the rate of the dehydration condensation reaction, the logarithm of the reciprocal of the acid dissociation constant (hereinafter abbreviated as pKa) is 3.5 to 6.
It is preferred to add an organic acid in the range of 0, preferably 4.0 to 5.0. For acids with a lower pKa,
The selectivity decreases, and for larger acids the reaction rate is slow. Examples of the organic acid used in the method of the present invention include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, cyclohexanecarboxylic acid, octanoic acid, crotonic acid, vinyl acetic acid, benzoic acid, anisic acid, and silicic acid. Cinnamic acid,
Examples thereof include phenylacetic acid and 2-naphthoic acid. The amount of the organic acid to be used is in the range of 50 to 2000% by weight, preferably 70 to 800% by weight, based on the catalytic metal. If the amount is less than this, the reaction rate is slow, and if it is too large, the selectivity decreases.

In the method of the present invention, it is preferable to use any of various reducing materials as the hydrogen acceptor. For example, olefins such as 1-octene, allylbenzene, crotonic acid, phenol, methylphenol, ethylphenol, isopropylphenol, butylphenol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, 2,6-di- tert-butyl-4-
Examples include phenols such as alkylphenols such as methylphenol, and alkoxyphenols such as 3-methoxyphenol and 4-methoxyphenol. Nitro compounds are not preferable because they are reduced to amine compounds and react with cyclohexanone in the reaction system. Among these, it is particularly preferable to use phenols as hydrogen acceptors, because they produce cyclohexanone as a raw material.

In the method of the present invention, a phenol corresponding to the cyclohexanone used as the raw material is used, and the cyclohexanone may be present in the reaction system in a catalytic amount. In this case, the hydrogen produced by the dehydrogenation of the intermediate produced by the reaction of the tris (arylamino) benzenes with the cyclohexanone is all used in the same reaction system for the reduction of phenols, that is, the production of cyclohexanone. Therefore, it is extremely efficient. Further, in the production of certain types of nuclear-substituted tris (diarylamino) benzenes, even when it is difficult to obtain the appropriate cyclohexanone, if a phenol is used, an excess amount of phenol is used instead of cyclohexanone. Hydrogen in advance and convert a part of phenols to cyclohexanone, and then react.
There are many advantages, such as a wide range of applications. In addition, since phenols are hydrogen acceptors and a source of the resulting cyclohexanone, the phenol containing cyclohexanone which is separated when the target product tris (diarylamino) benzenes is removed is The mixture can be recycled to the reaction system as it is.

In these cases, as the phenol used as a raw material, a phenol corresponding to the above-mentioned cyclohexanone is used, and the amount of the phenol used is tris (arylamino) benzene when the cyclohexanone coexists from the beginning. There is no particular problem as long as it is 3 equivalents or more, but it is usually advantageous to use it as a solvent,
It is preferable to use 4 to 20 times by mole, preferably 5 to 15 times by mole of tris (arylamino) benzenes.

The amount of cyclohexanone used is not particularly limited as long as it is at least about 0.1 mole times the catalytic amount with respect to the tris (arylamino) benzenes, but is preferably 0.5 to 3 times.
Molar times are better. If the amount is less than the above, the reaction rate is decreased, and if the amount is more than this, the yield of the target tris (diarylamino) benzenes is undesirably reduced.

When cyclohexanone is not used from the beginning of the reaction, an amount corresponding to the production of the above-mentioned appropriate amount of cyclohexanone relative to phenol, that is, about 0.2 mol times or more, preferably 1.0 to 6 mol Heating reaction may be performed after enclosing 0.0 mole times hydrogen in the reactor.

The catalyst used in these cases needs to be a catalyst having both functions of a dehydrogenation reaction and a reduction reaction, and usually a suitable hydrogenation reduction catalyst is also suitable for the dehydrogenation reaction. Therefore, what is necessary is just to use the same thing as the above-mentioned hydrogen transfer catalyst, and its use amount is also the same. The reaction temperature in the present invention is selected in the range of 150 to 300C, preferably 170 to 230C.

The produced tris (diarylamino) benzenes can be obtained by treating the mixture after the reaction according to a conventional method such as crystallization. For example, the reaction-terminated liquid is filtered to separate the catalyst. This recovered catalyst can be reused. Next, the filtrate is concentrated to recover phenols containing cyclohexanone. The fraction can be reused as a mixture. Tris (arylamino) benzenes in the kettle are purified by crystallization or the like.

[0022]

The present invention will be described below in detail with reference to examples. Example 1 In a 300 ml round bottom flask equipped with a reflux condenser equipped with a separator, a thermometer, and a stirrer, 5.28 g of 5% Pd / C manufactured by NE Chemcat, and 0.3 parts of propionic acid
5 g, 35.15 g of tris (phenylamino) benzene
(0.1 mol), 29.44 g of cyclohexanone (0.
3 mol) and 84.70 g (0.9 mol) of phenol, and heated to 180 ° C. while stirring the reactor.
The stirring was continued for 20 hours while maintaining the temperature at 180 to 190 ° C. The water produced during this period was charged with toluene and azeotroped, condensed in a reflux condenser, and then separated from the separator. Then, the reaction solution was diluted with toluene,
While maintaining the temperature at 140 ° C, 5% Pd / C
Was filtered off. When the filtrate was analyzed using high performance liquid chromatography, the conversion of tris (phenylamino) benzene was 100%, and the yield of tris (diphenylamino) benzene was 65.4%.

Example 2 The amount of cyclohexanone was changed from 29.44 g to 19.91 g.
The reaction and treatment were carried out in the same manner as in Example 1, except that the reaction was carried out for 46.5 hours. As a result, the conversion of tris (phenylamino) benzene was 100%, and the yield of tris (diphenylamino) benzene was 72.0%.

Example 3 The amount of 5% Pd / C was 5.94 g, and the acid was 0.40 g of benzoic acid.
g, tris (phenylamino) benzene
The reaction and treatment were carried out in the same manner as in Example 1 except that the reaction was carried out for 15.5 hours instead of using methylphenylamino) benzene.
As a result, the conversion of tris (4-methylphenylamino) benzene was 100%, and the yield of tris (N-4-methylphenyl-N-phenylamino) benzene was 71.5%.
Met.

Example 4 The amount of 5% Pd / C was 5.94 g, and the amount of propionic acid was 0.4.
0 g, the amount of cyclohexanone was 19.91 g, and tris (phenylamino) benzene was changed to tris (3-methylphenylamino) benzene for 25 hours.
Reaction and treatment were carried out in the same manner as in Example 1. As a result, Tris (3
The conversion of (-methylphenylamino) benzene is 100
%, And the yield of tris (N-3-methylphenyl-N-phenylamino) benzene was 80.2%.

Example 5 A reaction and treatment were carried out in the same manner as in Example 4 except that the reaction was carried out for 56 hours without using an organic acid as a promoter. As a result, the conversion of tris (3-methylphenylamino) benzene was 10
0%, the yield of tris (N-3-methylphenyl-N-phenylamino) benzene was 57%, and bis (N-3), an intermediate of tris (N-3-methylphenyl-N-phenylamino) benzene, was used. -Methylphenyl-N-phenylamino) -N'-3-methylphenylaminobenzene is 2
1% remained.

Example 6 The amount of 5% Pd / C was 5.94 g, and the acid was 1.98 g of benzoic acid.
g, the amount of cyclohexanone was 19.91 g, and the reaction and treatment were carried out in the same manner as in Example 1 except that the reaction was carried out for 45 hours while changing tris (phenylamino) benzene to tris (2-methylphenylamino) benzene. As a result, Tris (2
The conversion of (-methylphenylamino) benzene is 100
%, And the yield of tris (N-2-methylphenyl-N-phenylamino) benzene was 89.7%.

Comparative Example 1 In a 100 ml round bottom flask equipped with a reflux condenser equipped with a separator, a thermometer and a stirrer, 9.44 g (0.03 mol) of tribromobenzene, 16.3 g of diphenylamine.
75 g (0.1 mol), potassium carbonate 13.68 g
(0.1 mol), copper iodide 0.57 g and DMi 30 m
and the temperature was raised to 160 ° C. while stirring the inside of the reactor, and stirring was continued for 34 hours while gradually raising the temperature from 160 ° C. to 220 ° C. The water produced during this period was charged with toluene and azeotroped, condensed in a reflux condenser, and then separated from the separator. Next, the reaction solution was poured into methanol, and the formed precipitate was filtered and washed with methanol. After distilling off the methanol, the precipitate was dissolved in toluene,
After removing the insoluble portion by filtration, tris (diphenylamino) benzene was obtained at a yield of 6% by recrystallization.

[0029]

In the production of tris (diarylamino) benzenes, tris (arylamino) benzenes and cyclohexanone are used as a hydrogen transfer catalyst, a noble metal catalyst of Group VIII of the Periodic Table of the Elements, and in some cases, a pKa as a promoter.
By performing a heat reaction in the presence of an organic acid of 3.5 to 6.0, or by performing a heat reaction of a phenol corresponding to cyclohexanone under the same conditions in the presence of a catalytic amount of cyclohexanone. As a result, tris (diarylamino) benzene can be obtained more efficiently and more efficiently than in the conventional method.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-215653 (JP, A) JP-A-61-183250 (JP, A) "J. Am Chem. Soc.", 1992, Vol. 114, pages 5994-5998 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 211/54 B01J 23/44 C07C 209/24 C07B 61/00 300

Claims (8)

(57) [Claims] 1. In the presence of a hydrogen transfer catalyst, a compound represented by the following general formula (1): (Wherein, R represents hydrogen or a lower alkyl group) to a tris (arylamino) benzene represented by the following general formula (2): (In the formula, R ′ represents hydrogen or a lower alkyl group.)
Acid dissociation of cyclohexanone represented by
An organic acid having a logarithm of a reciprocal of a constant pKa of 3.5 to 6.0 is used.
The following general formula (3) characterized by using and reacting:
[Chemical Formula 3] [Chemical Formula 3] (Wherein, R and R ′ each represent hydrogen or a lower alkyl group.) A method for producing tris (diarylamino) benzenes represented by the formula: 2. The hydrogen transfer catalyst is a noble metal of Group VIII of the Periodic Table of the Elements.
The method according to claim 1, which is a catalyst. 3. The method according to claim 1, wherein a hydrogen acceptor is used.
Law. 4. A compound represented by the above general formula (2) as a hydrogen acceptor.
Phenols corresponding to cyclohexanone
The method of claim 1 for use. 5. A cyclohexane represented by the general formula (2)
In the presence of phenols corresponding to xanone,
The method according to claim 1, wherein the xanone is used in a catalytic amount. 6. A cyclohexane represented by the general formula (2)
Excess phenols corresponding to xanone are present,
Part of it is converted to cyclohexanone under hydrogen pressure
The method according to claim 1, wherein the reaction is carried out. 7. The tris obtained from a heated reaction mass
After separating (diarylamino) benzenes, cyclohexyl
Phenols including sanones are recycled to the reaction system for reuse
7. The method according to claim 5 or claim 6, wherein 8. A cyclohexane represented by the general formula (2)
Phenols corresponding to xanone are tris (aryl)
Amino) For use in excess of 4 to 20 mole times of benzene
The method according to claim 5 or claim 6, wherein