JPH0688953B2 - 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 specifically, it does not have monoalkenylanilines and alkenyl groups. The present invention relates to a method for producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes from phenols in high yield and high purity.

Technical background of the invention and its problems 2- (aminoaryl) -2- (hydroxyaryl) alkanes are used in synthetic rubber, polyurethane, epoxy resin, developer for thermal paper, 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 reacted in the presence of a phenolic solvent in the presence of an acidic catalyst, the yield of 2- (aminoaryl) -2- (hydroxyaryl) propanes is calculated. It is taught that the rate 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 sulfone is used as a catalyst. Protic acids such as acids, aluminum chloride, tin chloride, Lewis acids such as boron trifluoride, and cationic ion exchange resins are used. However, when the above compounds are used as catalysts, the conversion of vinylphenols is low, and the yield and selectivity of the target product, 2- (aminoaryl) -2- (hydroxyaryl) alkanes, are low. There was a problem.

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 desired 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 present inventors have conducted extensive studies to solve the problems associated with the above-described conventional techniques, and as a starting material, monoalkenylanilines different from the conventional method and phenols having no alkenyl group were used. The present invention has been completed by finding that the above problems can be solved all at once by using it.

OBJECT OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and comprises 2- (aminoaryl) -2-
(Hydroxyaryl) alkanes can be produced in high yield, and the target compound, 2- (aminoaryl) -2- (hydroxyaryl) alkanes, can be obtained with high recovery rate and high purity from the reaction mixture obtained after the reaction. Recoverable 2- (aminoaryl) -2- (hydroxyaryl)
It is intended to provide a method for producing alkanes.

SUMMARY OF THE INVENTION A method for producing a 2- (aminoaryl) -2- (hydroxyaryl) alkane according to the present invention is a method of producing a monoalkenylaniline and a phenol having no alkenyl group in the presence of a solid acid catalyst. It is characterized by reacting.

In the present invention, when a 2- (aminoaryl) -2- (hydroxyaryl) alkane is produced, a monoalkenylaniline and a phenol having no alkenyl group are used as starting materials. 2- (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 and 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.

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

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different and each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms or an aryl group, ₆ is hydrogen or a methyl group) In the above general formula [I], R ₂ , R ₃ and R ₆ are hydrogen and R ₁
A compound in which is a lower alkyl group, especially a methyl group, is preferably used. Also an alkenyl group The compound is located in the meta position or the para position with respect to the group, and when a synthetic zeolite is used as the catalyst, a compound in the meta position is preferably used.

Specific examples of such monoalkenylanilines include p-vinylaniline, m-vinylaniline, p-isopropenylaniline, m-isopropenylaniline, p-isobutenylaniline and m-isobutenylaniline. , 6-methyl-3-isopropenylaniline, m-isopropenyl-N-methylaniline, m-isopropenyl-N, N-dimethylaniline and the like are used.

Phenols Phenols having no alkenyl group used as a starting material in the present invention are represented by the following general formula [II].

(In the formula, R ₇ and R ₈ represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an aryl group.) Specific examples of such phenols include phenol, 0-cresol, m-cresol, 0 -Ethylphenol, 0-isopropylphenol, 2,6-xylenol, 2,
6-diethylphenol, 2-methyl-6-ethylphenol, 2,6-diisopropylphenol, 0-t-butylphenol, 2,6-di-t-butylphenol, 0-cumylphenol, 2,6-dicumylphenol , 0-phenylphenol, etc. are used. Of these, phenol, 0-cresol,
2,6-xylenol, 0-ethylphenol, 0-isopropylphenol, 2,6-diisopropylphenol, 0-t-butylphenol and 2,6-di-t-butylphenol are preferred.

Catalyst In the present invention, a solid acid catalyst is used when reacting the above monoalkenylanilines with phenols having no alkenyl group.

As the solid acid used in the present invention, various synthetic silica
Alumina, activated clay, acid clay or bentonite,
Layered clay minerals such as montmorillonite and synthetic mica (fluorite phlogopite tetrasilicon mica, teniolite, hectorite), synthetic zeolite, silica-titania, silica-zirconia, niobium oxide, calcium phosphate and the like are used. In addition, the above layered clay minerals, synthetic zeolite, etc.
Some are hydrogen ions, alkaline earth metal ions, rare earth,
Also used are those exchanged with transition metal ions.

Of these, montmorillonite or montmorillonite in which some or all of the interlayer ions are replaced with hydrogen ions, aluminum ions, zirconium ions, titanium ions, etc. is preferable. Of these, especially the interlayer ions
Preference is given to montmorillonite in which 10 to 100% has been exchanged with hydrogen ions or aluminum ions. This montmorillonite is a group of main minerals that make up clay such as bentonite, and is a kind of solid acid mainly composed of aluminum silicate and in which a part of aluminum is replaced by iron, magnesium, manganese and the like. Such montmorillonite has a three-layer structure, has an octahedral layer and a gibbsite layer, and its main component is generally represented by the following structural formula.

R _1/3 (Al _5/3 Mg _1/3 ) Si ₄ O ₁₀ (OH) ₂ ′ mH ₂ O where R is an interlayer cation, K ⁺ , Na ⁺ or Ca ²⁺
, And m can take any value.

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

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

These solid acid catalysts are powdery or granular, and the particle size thereof is preferably about 100 to 10 mesh.

When a solid acid catalyst is used in the reaction of monoalkenylanilines with phenols having no alkenyl group, 2- (aminoaryl) -2-
(Hydroxyaryl) alkanes are obtained in high yield and high selectivity, and the recovery rate of the target compound is high. On the other hand, when a 2- (aminoaryl) -2- (hydroxyaryl) alkane is produced from a monoalkenylphenol and an aniline by a conventionally known method, a conventionally known solid acid such as activated clay is used as a catalyst. However, it is difficult to produce the target compound with high yield and high selectivity, and the recovery rate of the target compound is low.

In the present invention, the recovery rate of the target compound is high because the present invention uses monoalkenylanilines and phenols having no alkenyl group as starting materials, and therefore high-boiling compounds are less likely to be produced. This is probably because the target compound was easily separated from the reaction mixture.

Reaction Conditions The reaction between the monoalkenylanilines and the phenols having no alkenyl group is preferably carried out in a state where the phenols are in a large excess, and usually 1 mol of the former and 3 mol or more of the latter, more preferably 5 mol. It is preferably used in a proportion of from 20 to 20 mol. The reaction temperature varies slightly depending on the type of catalyst, but is usually 130 to 200 ° C, especially 150 to 1
It is preferable to select in the range of 80 ° C. A suitable diluent may be used in the reaction. As such a diluent,
Various hydrocarbons, decane, dodecane, cumene, cymen, mesitylene, diisopropylbenzene, nitrobenzene, chlorobenzene, dichlorobenzene and the like can be used.

The reaction can be carried out batchwise or continuously. In the batch reaction, the amount of solid acid catalyst used is
It is usually about 3 to 20 parts by weight, preferably about 5 to 15 parts by weight, per 100 parts by weight. In the 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) alkane, from the reaction mixture obtained after completion of the reaction, usual separation and purification means are used. , As follows. The 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.

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

As described above, the general formula [III] according to the present invention (In the formula, R _{1 to} R ₇ are the same as the above), 2- (aminoaryl) -2- (hydroxyaryl) alkanes are obtained, and specific examples of the alkanes are 2- ( m-aminophenyl) -2- (P-hydroxyphenyl) propane, 2- (P-aminophenyl)-
2- (m-hydroxyphenyl) propane, 2- (P-aminophenyl) -2- (p-hydroxyphenyl) propane, 2-
(M-Aminophenyl) -2- (3 ', 5'-dimethyl-4'
-Hydroxy) propane, 2- (P-aminophenyl) -2-
(3 ', 5'-Dimethyl-4-hydroxy) propane, 2-
(P-Aminophenyl) -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-aminophenyl) -2-
(3'-isopropyl-4'-hydroxy) propane,
2- (m-aminophenyl) -2- (3 ', 5'-diisopropyl-4'-hydroxy) propane, 2- (P-aminophenyl) -2- (3'-methyl-4'-hydroxyphenyl)
Propane, 2- (m-aminophenyl) -2- (3'-t-butyl-4'-hydroxy) propane and the like are shown.

EFFECTS OF THE INVENTION In the present invention, monoalkenylanilines and phenols having no alkenyl group are used as starting materials when producing 2- (aminoaryl) -2- (hydroxyaryl) alkanes. , The desired product, 2- (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 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 Bentonite (Bengel) manufactured by Toyosyun Yoko Co., Ltd. 10 g
Was suspended in water of 1 and stirred well for 24 hours, then 5% -Al
150 ml of (NO ₃ ) ₃ aqueous solution was added, and the mixture was further stirred for 20 minutes and ion-exchanged with an aluminum mold. Bentonite ion-exchanged into aluminum mold is recovered by centrifugation,
Wash well with water and dry (40 ℃, 50mmHg, 10 hours)
After that, it was used for the reaction. The ion exchange rate of this aluminum ion exchange bentonite was 85 mol%.

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

After unreacted phenol was distilled from the reaction solution, about 4 times the amount of toluene was added to the concentrated solution and cooled to 10 ° C. to obtain crude crystals. When recrystallized with toluene, white fine crystals having a purity of 99.9% were obtained. The melting point was 192 ° C.

Example 2 Aluminum exchange type bentonite used in Example 1 10 g
Put phenol and 300g of phenol in a flask and keep at 170 ℃, and add a solution of 28g of metaisopropenylaniline dissolved in 30g of toluene while stirring well for about 1 hour.
After the dropping was completed, the reaction was continued for another hour.

When analyzed by gas chromatography, the conversion of metaisopropenylaniline was 88% and the composition of the product was 3-aminophenyl-4-hydroxyphenylpropane 7.
4.0%, 3-aminophenyl-2-hydroxyphenylpropane 8.5%, isopropenylaniline 2,3mer 9.2%,
The high-boiling substance was 8.3%. After completion of the reaction, unreacted phenol was distilled off, and 75 g of toluene was added for crystallization to collect a crude crystal, which was then recrystallized with methanol to give 3-aminophenyl-4-hydroxyphenylpropane as white powder. Obtained with a purity of 99.8%.

Example 3 A proton-exchanged 13Y zeolite was prepared by calcining ammonium-exchanged Y-type zeolite (Linde SK-613 manufactured by Union Carbide Co., Ltd.) in air at 600 ° C. for 3 hours.

13.2 g of this powdery catalyst and 250 g of phenol were placed in a flask and kept at 170 ° C., and 60 g of p-isopropenylaniline was added dropwise thereto over about 2 hours while stirring well.
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.

About 100 g of unreacted phenol was distilled from the reaction solution, 150 g of toluene was added, and the mixture was cooled to 10 ° C. to obtain light brown crude crystals. When recrystallized using methanol, white crystals having a purity of 99.9% were obtained. The melting point of this crystal is 19
It was 2 ° C.

Claims (2)

[Claims] 1. A 2- (aminoaryl) which is characterized by reacting a monoalkenylaniline with a phenol having no alkenyl group in the presence of a solid acid catalyst.
A method for producing a 2- (hydroxyaryl) alkane. 2. The solid acid catalyst is bentonite, montmorillonite or synthetic zeolite.
The method described in the section.