JPS62114942A - Production of 2-aminoaryl-2-hydroxyaryl alkane - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as an intermediate for synthetic rubber, etc., in high yield and purity, by reacting a monoalkenylaniline with a phenol in the presence of a solid acid catalyst. CONSTITUTION:An aniline expressed by formula I (R1, R2, R3, R4 and R5 are H, 1-6C alkyl or aryl; R6 is H or methyl), e.g. p-vinylaniline, is reacted with a phenol expressed by formula II (R7 and R8 are H, 1-6C alkyl or aryl), e.g. phenol or o-cresol, in the presence of a solid acid catalyst, e.g. bentonite, montmorillonite or synthetic zeolite, at 130-200 deg.C, particularly 150-180 deg.C to afford the aimed alkane expressed by formula III, e.g. 2-(m-aminophenyl)-2-(p- hydroxyphenyl)propane, etc. EFFECT:Since the compounds expressed by formulas I and II are used as starting materials, recovery ratio, purity, etc., are good.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes, and more particularly, to a method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes in high yield from monoalkenylanilines and phenols. The present invention also relates to a method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes with high purity.

Technical background of the invention and its problems 2-(aminoaryl)-2-(hydroxyaryl)alkanes are useful in synthetic rubbers, polyurethanes, epoxy resins, color developers for thermal paper, antioxidants, dyes, agricultural chemicals, etc. It is a compound useful as an intermediate.

Regarding the method for synthesizing these 2-(aminoaryl)-2-(hydroxyaryl)alkanes, for example, in Japanese Patent Publication No. 41-17,645@, vinylphenols such as isopropenylphenol and aniline are used as raw materials. A method is disclosed in which aromatic amines such as amines are reacted in the presence of an acidic catalyst such as hydrochloric acid, sulfuric acid, sulfonated polystyrene, or activated clay.

Furthermore, JP-A No. 55-64.552 discloses that when impropenylphenols and aromatic amines are reacted in the presence of an acidic catalyst in the coexistence of a phenolic solvent, 2-(
It is taught that the yield of aminoaryl)-2-(hydroxyaryl)propanes is improved.

In the method for producing 2-(aminoaryl')-2-(hydroxyaryl)alkanes from vinylphenols and aromatic amines described in the above publication, hydrochloric acid, sulfuric acid, phosphoric acid, toluene, etc. are used as catalysts. Protic acids such as sulfonic acid, Lewis acids such as aluminum chloride, tin chloride, and boron trifluoride, and cationic ion exchange resins are used. However, when the above compounds are used as catalysts, the conversion rate of vinylphenols is low, and the desired product 2-(aminoaryl)
There was a problem that the yield and selectivity of -2-(hydroxyaryl)alkanes were low.

In addition, vinyl phenols such as isopropenylphenol are used as starting materials, and since these vinyl phenols are compounds that easily condense, vinyl phenols may dimerize or tertiary in the reaction system.
It is easy to quantify and produce high boiling point products. Since the generated high-boiling products are mixed in the reaction mixture, the target product 2-(
When separating aminoaryl)-2-(hydroxyaryl)alkanes, it is not always easy to separate and purify the target product and the high-boiling point product, resulting in a low recovery rate and high purity of the target product. The problem was that it was difficult to obtain the desired product. Generally speaking, when a protonic acid such as hydrochloric acid is used as a catalyst, there is a problem in that it is not easy to separate and remove the catalyst from the reaction mixture.

The present inventors conducted intensive research to solve the problems associated with the conventional technology as described above, and found that the above problems could be solved by using monoalkenylanilines and phenols, which are different from the conventional method, as starting materials. The present invention has been completed by discovering that these problems can be solved at once.

The present invention aims to solve the problems associated with the prior art as described above, and is directed to 2-(aminoaryl)-
2-(hydroxyaryl)alkanes can be produced in high yield, and the target compound 2-(aminoaryl)-2-(hydroxyaryl)alkane can be produced with high recovery rate and high yield from the reaction mixture obtained after the reaction. The object of the present invention is to provide a method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes that can be recovered in high purity.

Summary of the Invention The method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes according to the present invention is characterized by reacting monoalkenylanilines and phenols in the presence of a solid acid catalyst. .

In the present invention, when producing 2-(aminoaryl>-2-(hydroxyaryl)alkanes, monoalkenylanilines and phenols are used as starting materials, so the desired product 2-(aminoaryl) aryl)-2-(hydroxyaryl)alkanes can be obtained in high yield and high selectivity, and the target product can be recovered from the reaction mixture with high recovery rate and high purity.

The method for producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes according to the present invention will be specifically described below.

Monoalkenyl anilines The monoalkenyl anilines used as starting materials in the present invention are represented by the following general formula [1].

(In the formula, R1, R2, R3, R4, R5, may be the same or different and each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group, and R6 is hydrogen or methyl In the general formula [1], R2, R3, and R6 are hydrogen, and R1 is a lower alkyl group, particularly a methyl group, which is preferably used. Further, the compound is located at the meta or rose position relative to the alkyl group, and when a synthetic zeolite is used as the catalyst, a compound located at the meta position is preferably used.

Specifically, such monoalkenylanilines include p-vinylaniline, m-vinylaniline, and p-vinylaniline.
Isopropenylaniline, m-isopropenylaniline, p-isobutenylaniline, m-isobutenylaniline, 6-methyl-3-isopropenylaniline, m-isopropenyl-N-methylaniline, phosphorus, m-isopropenylaniline N,N-dimethylaniline and the like are used.

Phenols and anilines used as starting materials in the present invention are:
It is represented by the following general formula [I[].

(In the formula, R7 and R8 represent hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group.) Specific examples of such phenols include phenol, O-cresol, 1-cresol, and 0-ethyl. Phenol, O-isopropylphenol, 2゜6-xylenol, 2,6-diethylphenol, 2-methyl-
6-ethylphenol, 2.6-diituprobylphenol, 0-1-butylphenol, 2.6-di-t-butylphenol, 0-cumylphenol, 2,6-shifumylphenol, O-phenylphenol, etc. used. Among these, phenol, 0-cresol, 2.6-
Xylenol, 0-ethylphenol, 0-isopropylphenol, 2,6-diitupropylphenol, 0
-1-butylphenol and 2,6-di-t-butylphenol are preferred.

Catalyst In the present invention, a solid acid catalyst is used when reacting monoalkenylanilines and phenols as described above.

The solid acids used in the present invention include various synthetic silicas,
Alumina, activated clay, acid clay or bentonite,
Layered clay minerals such as montmorillonite, synthetic mica (fluorophlogopite tetrasilicon mica, taeniolite, hectorite), synthetic zeolite, silica-titania, silica-zirconia, niobium oxide, calcium phosphate, etc. are used. Furthermore, the above-mentioned layered clay minerals, synthetic zeolites, etc., in which a portion is exchanged with hydrogen ions, alkaline earth metal ions, rare earth metal ions, transition metal ions, etc., may also be used.

Among these, montmorillonite or montmorillonite in which part or all of the living ions are exchanged with hydrogen ions, aluminum ions, zirconium ions, titanium ions, etc. is preferred.

Among these, montmorillonite in which 10 to 10% of interlayer ions are exchanged with hydrogen ions or aluminum ions is particularly preferred. Montmorillonite is part of the main minerals that make up clay such as bentonite, and is mainly composed of silica aluminum, with some of the aluminum being iron and
A type of solid acid substituted with magnesium, manganese, etc. Such montmorillonite has a three-layer structure, has a gibbsite layer in the octahedral layer, and the main component is generally represented by the following structural formula.

Ry, (Al, 4 MqV, l 51401O(○
H12' ml, 0 where R is an interlayer cation and K
, Na+ or c a 2 +a, and m can take any value.

Commercially available montmorillonite catalysts include Nisben and Bengel sold by Toyojun Yoko Co., Ltd., and any of them can be used in the present invention.

Synthetic zeolites are necessarily hydrated aluminosilicate salts of alkali metals or alkaline earth metals with the general formula M, [(
A compound represented by AUO2)
Zeolite-Y and zeolite-1 mordenite are preferably used.

Also preferably used are synthetic zeolites in which M and ions of these zeolites are exchanged with hydrogen ions, alkaline earth metal ions, and rare earth transition metal ions. It is preferred that the synthetic zeolite be calcined in air at a temperature of 300 to 600'C before use.

These solid precatalysts are in the form of powder or particles, and the particle size is preferably about 100 to 10 mesh.

When a solid acid catalyst is used to react monoalkenylanilines with phenols, the target compound, 2-(aminoaryl)-2-(hydroxyaryl)alkanes, can be obtained in high yield and high selectivity. Moreover, the recovery rate of the target compound is also high.

On the other hand, by a conventionally known method, 2-(aminoaryl)-2-
When producing (I-nitroxyaryl)alkanes, it is difficult to produce the target compound in high yield and high selectivity even if conventionally known solid acids such as activated clay are used as catalysts. However, the recovery rate of the target compound is also low.

The reason why the recovery rate of the target compound is high in the present invention is that monoalkenylanilines and phenols are used as starting materials in the present invention, so high boiling point compounds are not produced much, and therefore the target compound is recovered from the reaction mixture. This is thought to be due to the ease of separation.

Reaction conditions The reaction between monoalkenylanilines and phenols is as follows:
It is preferable to use a large excess of phenols, and it is usually preferable to use the latter in a ratio of 3 moles or more, more preferably 5 to 20 moles, per 1 mole of the former. The reaction temperature varies slightly depending on the type of catalyst, but is usually 130
It is preferable to select the temperature within the range of 150 to 180°C, particularly 150 to 180°C. A suitable diluent may be used during the reaction. As such diluents, various hydrocarbons such as decane, dodecane, cumene, cymene, mesitylene, diisopropylbenzene, nitrobenzene, chlorobenzene, dichlorobenzene, etc. can be used.

The reaction can be carried out batchwise or continuously. In the batch reaction, the amount of solid acid catalyst used is usually about 3 to 20 parts by weight, especially about 5 parts by weight, per 100 parts by weight of the reaction raw materials.
It is preferable that the number of sides is approximately 15 to 15 times. Further, in a continuous reaction, it is preferable to carry out the reaction so that the residence time is about 0.2 to 1 hour.

In order to separate and purify the target compound, 2-(aminoaryl)-2-(hydroxyaryl)alkanes, from the reaction mixture obtained after the completion of the reaction, ordinary separation and purification means are used. , you can do as follows. The catalyst is removed from the reaction mixture by filtration, etc., and the resulting filtrate is cooled to precipitate crude crystals of the target compound. By recrystallizing the crude crystals from a suitable solvent, purified crystals of the target compound can be obtained.

In the present invention, the solid acid catalyst after use can be reused by washing it with acetone, methanol, ethanol, etc. under heating.

As described above, the 2-(aminoaryl)-2-(hydroxyaryl) alkanes represented by the general formula [I11] (wherein R1-R7 are the same as above) according to the present invention are obtained. Specifically, the alkanes include 2-(m-aminophenyl)-
2-(P- and droxyphenyl)propane, 2-(P-
aminophenyl)-2-(m-hydroxyphenyl)propane, 2-(P-aminophenyl)-2-(kanohydroxyphenyl)propane, 2-(m-7minophenyl)
-2-(3',5-dimethyl-4'-hydroxy)propane, 2-(P-7minophenyl)-2-(3',5'
-dimethyl-4-hydroxy)propane, 2-(amiminophenyl)-2-(3°,5-diethyl-4-hydroxy)propane, 2-[p-(N,N-dimethylamino)phenyl] -2 -(P-hydroxyphenyl)propane, 2-(m-aminophenyl)-2-(3-methyl-4°-hydroxy)propane, 2-(m-7minophenyl)-2-(3"-isopropyl-4 -hydroxy)
Propane, 2-(m-7minophenyl)-2-(3″,
5'-diisopropyl-4-hydroxy)propane, 2
-(P-aminophenyl)-2-(3-methyl-4゛-
hydroxyphenyl)propane, 2-(m-aminephenyl)-2-(3'-t-butyl-4°-hydroxy)
Propane etc. are shown.

Effects of the Invention In the present invention, when producing 2-(aminoaryl)-2-(hydroxyaryl)alkanes, monoalkenylanilines and phenols are used as starting materials. 1q of -(aminoaryl)-2-(hydroxyaryl)alkanes can be obtained in high yield and high selectivity, and the target product can be recovered from the reaction mixture with high recovery rate and high purity.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Bentonite manufactured by Toyojun Yokosha (product name Bengel) 10q
was suspended in 1ρ of water and stirred well for 24 hours, then 5%-A
150 d of β (NO3)3 aqueous solution was added and stirred for 20 minutes, followed by ion exchange with an aluminum type. The bentonite ion-exchanged into aluminum type is recovered by centrifugation, thoroughly washed with water, and roughly dried (40'C1).
50C15O for 10 hours) and then used for the reaction. The ion exchange rate of this aluminum ion-exchanged bentonite was 85 mol%.

7.5 g of the aluminum ion-exchanged bentonite thus obtained and 250 g of phenol were placed in a flask and kept at 160°C, and 55 g of isopropenylaniline was added to the flask.
was added dropwise over about 2 hours with good stirring, and then the reaction was continued for about 1 hour. As a result of gas chromatography analysis of the reaction solution, the conversion rate of p-isopropenylaniline was 94.0%, and the product selectivity (p
-isopropenylaniline standard) were as shown in Table 1.

Table 1 Product Selectivity (%) Dimer, trimer of p-isopropenylaniline 2.7 Other high boiling point substances 2.1 After distilling unreacted phenol from the reaction solution, approximately 4 times the amount was added to the concentrated solution. of toluene was added and cooled to 10°C to obtain crude crystals. When it was roughly recrystallized with toluene, white microcrystals with a purity of 99.9% were obtained. This melting point was reached at 192°C.

Example 2 Aluminum exchangeable bentonite 10 used in Example 1
Put g and phenol 300Q into a flask and heat to 170'C.
and metaisopropenylaniline 28CJ at 30C
A solution of I dissolved in toluene was added dropwise over about 1 hour while stirring well, and after the dropwise addition was completed, the reaction was continued for about 1 hour.

When analyzed by gas chromatography, the conversion rate of metaisopropenylaniline was 88%, and the composition of the product was 74.0% of 3-aminophenyl-4-droxyphenylpropane, 3-aminophenyl-2 -Hydroxyphenylpropane was 8.5%, isopropenylaniline di-trimer was 9.2%, and high boilers were 8.3%. After the reaction, unreacted phenol was distilled off and toluene 75% was added.
3-aminophenyl-4-hydroxyphenylpropane as a white powder with a purity of 99.8% by collecting crude crystals and recrystallizing them with methanol.
I got it from

Example 3 Ammonium exchange +% YW zeolite (Linde 5K-613 manufactured by Union Carbide Co.) was heated at 60°C in air.
A proton-exchanged 13Y zeolide was prepared by calcining the mixture for 3 hours.

13.2 g of this powdered catalyst and 250 g of phenol were placed in a flask and maintained at 170°C, and 60 g of isopropenylaniline was added dropwise to this with good stirring over about 2 hours, and the reaction was continued for about 1 hour. . As a result of analyzing the reaction solution by gas chromatography, the conversion rate of p-isopropenylaniline was 98.0%, and the selectivity of the product (based on p-isopropenylaniline) was as shown in Table 2.

Table 2 Product Selectivity (%) 2.3-mer of p-isopropenylaniline 2.2 Other high boiling point substances 1.3 After wetting out about 100 g of unreacted phenol from the reaction solution, 150 q of toluene was added, When cooled to 'C, light brown crude crystals were obtained. When it was recrystallized using methanol, white crystals with a purity of 99.9% were obtained. The melting point of this crystal was 192°C.

Claims (2)

[Claims] (1) 2- characterized in that monoalkenylanilines and phenols are reacted in the presence of a solid acid catalyst.
A method for producing (aminoaryl)-2-(hydroxyal)alkanes. (2) The method according to claim 1, wherein the solid acid catalyst is bentonite, montmorillonite, or synthetic zeolite.