JPH0649672B2 - Method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkane - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes, and more particularly, to high yields from monoalkenylphenols and anilines. And a method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes with high selectivity.

Technical background of the invention and its problems 2- (aminoaryl) -2- (hydroxyaryl) alkanes are used in synthetic rubber, polyurethane, epoxy resin, thermal paper developer, antioxidant, dye, pesticide, etc. It is a compound useful as an intermediate.

This 2- (aminoaryl) -2- (hydroxyaryl)
Regarding a method for synthesizing alkanes, for example, Japanese Patent Publication No. 41-17,645 discloses that vinylphenols such as isopropenylphenol and aromatic amines such as aniline are used as raw materials, and these are hydrochloric acid, sulfuric acid, A method of reacting in the presence of an acidic catalyst such as sulfonated polystyrene and activated clay is disclosed. In addition, JP-A-55-6
In 4,552, when isopropenylphenols and aromatic amines are allowed to react in the presence of an acidic catalyst in the presence of a phenol solvent, the yield of 2- (aminoaryl) -2- (hydroxyaryl) propanes is calculated. It is taught that the rate is improved.

Thus, in the method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes from vinylphenols and aromatic amines described in the above publication,
As the catalyst, a protonic acid such as hydrochloric acid, sulfuric acid, phosphoric acid or toluenesulfonic acid, a Lewis acid such as aluminum chloride, tin chloride or boron trifluoride, or a cationic ion exchange resin is used. However, when the above compound is used as a catalyst, the conversion rate of vinylphenols is low and the desired product, 2- (aminoaryl) -2, is obtained.
There is a problem that the yield and selectivity of-(hydroxyaryl) alkanes are low.

Further, vinylphenols such as isopropenylphenol are used as a starting material, and since these vinylphenols are compounds that easily condense, the vinylphenols dimerize or 3
A high boiling point product is likely to be generated due to quantification. Since the produced high boiling point product is mixed in the reaction mixture, when separating the target product 2- (aminoaryl) -2- (hydroxyaryl) alkane from the reaction mixture obtained after the reaction, Separation and purification of the target product and the high boiling point product are not always easy, and thus there is a problem that the recovery rate of the target product is low and it is difficult to obtain the target product with high purity. Further, when a protic acid such as hydrochloric acid is used as the catalyst, there is a problem that it is not easy to separate and remove the catalyst from the reaction mixture.

The inventors of the present invention have conducted extensive studies to solve the problems associated with the above-mentioned conventional techniques, and found that 2- (aminoaryl) -2- (hydroxyaryl) alkanes are obtained from monoalkenylphenols and anilines. When a synthetic zeolite is used as a catalyst in the production of bisphenol, the conversion of monoalkenylphenols is dramatically improved, and the target compound, 2- (aminoaryl) -2- (hydroxyaryl)
2- (Aminoaryl)-, which is the target compound, can be obtained with high yield and high selectivity of alkanes, and using monoalkenylphenols in which the alkenyl group is in the meta position with respect to the hydroxyl group as a raw material. High yield and selectivity of 2- (hydroxyaryl) alkanes,
Furthermore, 2- (aminoaryl) -2- from the reaction mixture
The present invention has been completed by finding that the recovery rate of (hydroxyaryl) alkanes can be increased.

OBJECT OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above at once, and comprises 2- (aminoaryl) -2- from monoalkenylphenols and anilines.
(Hydroxyaryl) alkanes can be obtained in high yield and high selectivity, and the desired compound, 2- (aminoaryl) -2-, is obtained from the reaction mixture obtained after the reaction.
2- (aminoaryl) -2-, which enables recovery of (hydroxyaryl) alkanes with high recovery and high purity
An object is to provide a method for producing (hydroxyaryl) alkanes.

SUMMARY OF THE INVENTION The method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes according to the present invention is characterized by reacting monoalkenylphenols and anilines in the presence of a synthetic zeolite catalyst. .

In the present invention, since a synthetic zeolite catalyst is used in the reaction of monoalkenylphenols and anilines, the desired product, 2- (aminoaryl) -2-
(Hydroxyaryl) alkanes can be obtained in a high yield and a high selectivity, and the target product can be recovered from the reaction mixture with a high recovery rate and a high purity.

DETAILED DESCRIPTION OF THE INVENTION The method for producing a 2- (aminoaryl) -2- (hydroxyaryl) alkane according to the present invention will be specifically described below.

Monoalkenylphenols Monoalkenylphenols used as a starting material in the present invention are represented by the following general formula [I].

(Wherein _{R 1, R 2, R 3} , R 4 may be different may be the same, are hydrogen or an alkyl group having 1 to 6 carbon atoms, m is an integer of 0-4. As the alkyl group, a lower alkyl group, particularly a methyl group or an ethyl group is preferable, and the --CR ₂ ═CR ₃ --R ₄ group is used in the meta or para position with respect to the --OH group.
Those in the meta position are particularly preferable.

In the above monoalkenylphenols, those in which the alkenyl group is in the meta position with respect to the hydroxyl group are preferable because the phenols in which the alkenyl group is in the meta position are more preferable than those in which the alkenyl group is in the para position. This is because it is difficult to dimerize or trimerize, and thus it is difficult to form a high boiling point product in the reaction product, which facilitates separation and purification of the target product.

Specific examples of such monoalkenylphenols include m-vinylphenol, p-vinylphenol and m-vinylphenol.
Isopropenylphenol, p-isopropenylphenol, m-isobutenylphenol, p-isobutenylphenol, 2-methyl-5-isopropenylphenol, 2-ethyl-5-isopropenylphenol and the like are used.

Anilines The anilines used as a starting material in the present invention are
It is represented by the following general formula [II].

(In the formula, R ₄ , R ₅ , R ₆ and R ₇ are hydrogen or an alkyl group having 1 to 3 carbon atoms.) Specific examples of such anilines include aniline, N-methylaniline, N , N-dimethylaniline, N-ethylaniline, 2-methylaniline, 2,6-xylidine (2,6-
Dimethylaniline), 3-isopropylaniline and the like are used.

Synthetic Zeolite In the present invention, a synthetic zeolite catalyst is used when the above monoalkenylphenols and anilines are reacted.

The synthetic zeolite is a hydrous aluminosilicate of an alkali metal or an alkaline earth metal and has a general formula ▲ M ^{n +} _{x / y}
▼ A compound represented by [(AlO ₂ ) X (SiO ₂ ) y] .mH ₂ O, of which, in the present invention, zeolite-
X, zeolite-Y, zeolite-L, mordenite are preferably used. In the present invention, synthetic zeolites obtained by exchanging ^{Mn +} ions of these zeolites with protons, alkaline earth metal ions, rare earth metal or transition metal ions are also used. Also, before use, in air 300
It is also possible to use synthetic zeolite calcined at a temperature of up to 600 ° C.

When a synthetic zeolite is used as a catalyst in the reaction of monoalkenylphenols with anilines, the target compound, 2- (aminoaryl) -2- (hydroxyaryl) alkanes, is obtained in high yield and high selectivity. To be On the other hand, when the catalyst is an activated clay or an ion exchange resin that is classified as an acidic catalyst similar to synthetic zeolite, or a protic acid such as hydrochloric acid or sulfuric acid, it is a target compound with high yield and high selectivity. It is not possible to obtain 2- (aminoaryl) -2- (hydroxyaryl) alkanes. Specifically, when the reaction of metaisopropenylphenol and aniline is carried out using a calcium-exchanged Y-type zeolite catalyst, the conversion rate of metaisopropenylphenol is 98.5%, which is the target compound 2- ( While the selectivity of 3'-hydroxyphenyl) -2- (4 "-aminophenyl) propane is 88.7%, when the above reaction is carried out using a strong acid type ion exchange resin as a catalyst, The conversion rate of isopropenylphenol is remarkably 38.0%, and the selectivity of the target compound is 3%.
Remarkably low at 2.0%. Similarly, when activated clay was used as the catalyst, the conversion of metaisopropenylphenol was low at 73.0% and the selectivity of the target compound was 6%.
It is as low as 9.5%.

When a synthetic zeolite is used as a catalyst, monoalkenylphenols in which the alkenyl group is in the meta position and the para position with respect to the hydroxyl group can be used as a starting material, and particularly, the alkenyl group is in the meta position with respect to the hydroxyl group. Those in are preferred. When monoalkenylphenols in which the alkenyl group is in the meta position relative to the hydroxyl group are used as starting materials, the target compound, 2- (aminoaryl) -2- (hydroxyaryl), is obtained in high yield and high selectivity.
Alkanes are obtained.

Furthermore, when the synthetic zeolite is used as a catalyst in the present invention, the target compound, 2- (aminoaryl) -2- (hydroxyaryl) alkane, can be recovered from the reaction mixture at a high recovery rate. For example, when using synthetic zeolite as a catalyst in the above reaction example,
The recovery rate of the target compound reaches 87%, whereas the recovery rate of the target compound is 32% when the strong acid type ion exchange resin is used as the catalyst, and when the activated clay is used as the catalyst. The recovery rate of the target compound is 57%. This is because when a synthetic zeolite is used as a catalyst, high boiling point compounds such as dimers and trimers of monoalkenylphenols are less likely to be produced, as compared with the case of using other acidic catalysts. This is probably because the target compound can be easily separated from the reaction mixing section.

Reaction conditions The reaction between monoalkenylphenols and anilines using the synthetic zeolite catalyst according to the present invention is 100 to 25
It is preferably carried out at a temperature of 0 ° C, preferably 150 to 200 ° C.

Moreover, it is preferable to use the aniline in an amount of 0.5 to 50 mol per mol of the monoalkenylphenol.
Synthetic zeolite catalysts are monoalkenylphenols 1
1 to 100 parts by weight, preferably 5 to 100 parts by weight
It is preferably used in an amount of 50 parts by weight. The particle size of the synthetic zeolite catalyst is preferably about 200 to 10 mesh.

A solvent may coexist in the reaction system, and examples of such a solvent include dichlorobenzene, bromotoluene, diisopropylbenzene, tetralin, nitrobenzene, and nitrotoluene.

The reaction according to the present invention can be carried out batchwise or continuously.

In order to separate and purify the target compound, 2- (aminoaryl) -2- (hydroxyaryl) alkane, from the reaction mixture obtained after completion of the reaction, usual separation and purification means are used. , As follows. First, the synthetic zeolite catalyst is removed from the reaction mixture by filtration and the resulting filtrate is cooled to precipitate crude crystals of the target compound. The crude crystals are recrystallized from an appropriate solvent to obtain purified crystals of the target compound.

As described above, the general formula [III] according to the present invention (In the formula, R _{1 to} R ₇ and m are the same as the above), 2- (aminoaryl) -2- (hydroxyaryl) alkanes can be obtained. Specific examples of the alkanes include 2- (3′-aminophenyl) -2- (4 ″ -hydroxyphenyl) propane and 2- (4′-aminophenyl)
-2- (3 "-hydroxyphenyl) propane, 2- (4'-aminophenyl) -2- (4" -hydroxyphenyl) propane, 2- (3'-aminophenyl) -2- (3 ", 5 ″ -Dimethyl-
4 ″ -hydroxy) propane, 2- (4′-aminophenyl) -2- (3 ″, 5 ″ -dimethyl-4-hydroxy) propane,
2- (4′-aminophenyl) -2- (3 ″, 5 ″ -diethyl-4 ″
-Hydroxy) propane, 2- [4 '-(N, N-dimethylamino) phenyl] -2- (4 "-hydroxyphenyl) propane, 2- (3'-aminophenyl) -2- (3" -methyl -4 "-
Hydroxy) propane, 2- (3'-aminophenyl) -2-
(3 ″ -isopropyl-4′-hydroxy) propane, 2-
(3′-aminophenyl) -2- (3 ″, 5 ″ -diisopropyl-
4 ″ -hydroxy) propane, 2- (4′-aminophenyl) -2- (3 ″ -methyl-4 ″ -hydroxyphenyl) propane, 2- (3′-aminophenyl) -2- (3 ″ -t -Butyl-4 ″
-Hydroxy) propane and the like are indicated.

EFFECTS OF THE INVENTION In the present invention, since a synthetic zeolite catalyst is used in the reaction of monoalkenylphenols with anilines, the target product, 2- (aminoaryl) -2- (hydroxyaryl) alkanes, can be obtained in high yield. And a high selectivity, and the target product can be recovered from the reaction mixture with high recovery and high purity.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Sodium-type 13Y zeolite powder (Linde LZ-Y52 manufactured by Union Carbide Co., Ltd.) was cation-exchanged by an ordinary method using an aqueous calcium nitrate solution,
A powdery Ca-exchanged Y-type zeolite (exchange rate 67%) was prepared. After the obtained Ca-exchanged Y-type zeolite catalyst was calcined in air at a temperature of 500 ° C., the obtained powder was 10.2 g.
Then, 200 g of aniline and 200 g of aniline were placed in a flask, and 33 g of m-isopropenylphenol was added dropwise thereto while maintaining the temperature at 180 ° C. with good stirring for about 2 hours, and then the reaction was continued at 180 ° C. for another hour.

When the obtained reaction mixture was analyzed by gas chromatography, the conversion of m-isopropenylphenol was 9
It was 8.5%, and the selectivity of the product was as shown in Table 1.

Next, the reaction mixture was hot filtered at 110 ° C. to remove the synthetic zeolite catalyst, and the obtained filtrate was cooled to 10 ° C. to obtain light brown crude crystals. The crude crystals were dissolved in 150 m of methanol and recrystallized to obtain 2- (3'-hydroxyphenyl) -2- (4 "-aminophenyl) propane white powdery crystals. The purity of the crystals was 99. The melting point was 1.9% and the melting point was 168 ° C. Further, the solution-based recovery rate after the reaction was 87%.
Shown in.

Example 2 A rare earth metal ion-exchange type 13Y zeolite (Linde SK-500 manufactured by Union Carbide Co., Ltd.) was calcined at 500 ° C. for 2 hours, and then a reaction between metaisopropenylphenol and aniline was performed in the same manner as in Example 1. . The results are shown in Table 1.

Example 3 As a catalyst, a reaction between metaisopropenylphenol and aniline was carried out in the same manner as in Example 1 except that a proton exchange mordenite (Zeolone 100H manufactured by Norton Co., Ltd.) was calcined at 400 ° C. for 3 hours and then used. . The results are shown in Table 1.

Comparative Example 1 A reaction between metaisopropenylphenol and aniline was carried out in the same manner as in Example 1 using 10 g of a strong acid type ion exchange resin (Amberlyst-15) manufactured by Rohm and Haas Company, USA as a catalyst. When the reaction solution was analyzed after the reaction was completed, the conversion of metaisopropenylphenol was 3
It was 8.0%, and as a reaction product, 42% of a dimer of meta-isopropenylphenol was produced, and the target compound, 2- (3'-hydroxyphenyl) -2- (4 "-. Aminophenyl) propane was produced in only 32%.

It was difficult to obtain the desired product by crystallization from the concentrated liquid obtained after distilling unreacted aniline from the reaction mixture. In order to obtain pure 3-hydroxyphenyl-4-aminophenylpropane, it is necessary to distill aniline under reduced pressure and then repeat recrystallization with methanol, and the recovery rate (based on the solution after the reaction) is 32. %Met. The results are shown in Table 1.

Comparative Example 2 Activated clay powder 7.3 manufactured by Japan Activated Shirado Co., Ltd. (K-500)
After baking g at 400 ° C., the reaction between metaisopropenylphenol and aniline was carried out in the same manner as in Example 1 except that this was used as a catalyst. The results are shown in Table 1.

Next, the reaction mixture was filtered while hot at 110 ° C. to remove the catalyst and then cooled to 10 ° C. However, since the proportion of by-products was large, crude crystals could not be obtained as they were. Then, unreacted aniline was completely distilled off, 200 g of toluene was added, and the mixture was cooled to 0 ° C. to obtain light brown crude crystals for the first time.

By recrystallizing the obtained crystal with methanol, 2-
(3'-Hydroxyphenol) -2- (4 "-aminophenyl) propane was obtained.

The crystal has a purity of 98.8% and a melting point of 167 ° C.
The recovery rate of 2- (3′-hydroxyphenyl) -2- (4 ″ -aminophenyl) propane (based on the reaction solution) was 57%.

Example 4 5-isopropenyl instead of m-isopropenylphenol
Example 1 except that 2-methylphenol was used as the raw material
The reaction was carried out in the same manner as in.

The conversion rate of 5-isopropenyl-2-methylphenol is 9
At 9.0%, the product selectivity is 2- (3'-hydroxy-4 '
-Methylphenyl) -2- (4 "-aminophenyl) propane was 87.5% and 2- (3'-hydroxy-4'-methylphenyl) -2- (2" -aminophenyl) propane was 5.7. %,Five-
Isopropenyl-2-methylphenol dimers and trimers were 3.3%, and other high-boiling substances were 3.5%.

Example 5 A reaction was performed in the same manner as in Example 1 except that 2,6-xylidine was used instead of using aniline.

The conversion of m-isopropenylphenol was 85.1%, and the selectivity of the product was 2- (3'-hydroxyphenyl) -2- (4 "-amino-3", 5 "-dimethylphenyl). Propane 87.8%, m-isopropenylphenol 2,
The trimer was 5.6% and the other high boiling substances were 6.6%.

Claims (5)

[Claims] 1. A process for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes, which comprises reacting monoalkenylphenols with anilines in the presence of a synthetic zeolite catalyst. 2. The method according to claim 1, wherein the synthetic zeolite catalyst is mordenite, zeolite-X, zeolite-Y or zeolite-L. 3. The method according to claim 1, wherein monoalkenylphenols in which the alkenyl group is in the meta position with respect to the hydroxyl group are used. 4. The method according to claim 1, wherein the monoalkenylphenols are m-isopropenylphenols. 5. The method according to claim 1, wherein the aniline is aniline or 2,6-xylidine.