JPS62132843A - Purification of bis (p-aminocumyl)benzene compound - Google Patents

Abstract

PURPOSE:To purify a crude bis(p-aminocumyl)benzene compound in high purity and recovery, by crystallizing the compound using a 7-13C alkylbenzene or its mixture with a 7-13C aliphatic hydrocarbon as a crystallization solvent. CONSTITUTION:Crude bis(p-aminocumyl)benzene compound is crystallized by using a solvent composed of a 7-13C alkylbenzene (e.g. toluene, ethyltoluene, xylene, cumene, trimethylbenzene, diethylbenzene, etc.) or a mixed solvent composed of the above alkylbenzene and a 7-13C aliphatic hydrocarbon (e.g. heptane, octane, nonane, decane, undecane, dodecane, etc.) (the weight ratio of alkylbenzene to aliphatic hydrocarbon is preferably 0.25-5).

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for purifying bis(p-aminocumyl)benzenes, and more particularly, to a method for purifying bis(p-aminocumyl)benzenes using a specific solvent system. Regarding.

Technical background of the invention and its problems Bis(aminocumyl)benbines are compounds useful as raw materials for synthetic resins such as polyamides, polyimides, polyamideimides, and epoxies, resin additives, dyes, and the like.

For methods for synthesizing bis(p-aminocumyl)benzenes, see, for example, U.S. Pat. No. 3,267;
No. 145 discloses a method of reacting α,α゛-dihydroxydiisopropylbenzenes as raw materials with anilines in the presence of an activated clay catalyst, and US Pat. No. 3,365,347 The specification discloses a method of reacting diisopropenylbenpines and anilines in the presence of an activated clay catalyst. Zarani West German Patent No. 2,111,193 and West German Patent No. 2,111,
No. 194 also discloses a method for producing bis(p-aminecumyl)benzenes by a similar reaction using an acid clay catalyst.

In the above method, since bis(p-aminocumyl)benzenes are mixed together with various reaction by-products, it is necessary to separate and purify bis(p-aminocumyl)benzenes. However, the above-mentioned West German patent specification does not contain any description of a method for purifying bis(aminocumyl)benzenes, and the above-mentioned US patent specification does not mention that bis(aminocumyl)benzenes can be purified by a crystallization operation using ethanol or isopropanol as a solvent. It is only described that it can be crystallized.

However, according to the method for purifying bis(p-aminocumyl)benzenes using methanol or isopropanol as taught in the above-mentioned US patent specification, certain bis(0-
In the case of aminocumyl>benzenes, the problem often occurred that the compound could not be crystallized by the crystallization operation.

Furthermore, in the case of certain bis(p-aminocumyl)benzenes, when methanol, isopropanol, or tetrahydrofuran is used, the recovery rate during crystallization of the compound is not very good, and the purity of the purified product obtained is low. However, there was a problem that the results were not always satisfactory.

The present inventors solved the problems associated with the prior art as described above, and recovered high-purity bis(p-aminocumyl)benzenes with a high recovery rate. As a result of intensive studies on purification methods, the present invention was completed by discovering that the compound can be crystallized using a specific solvent system.

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above. ~
The purpose of the present invention is to provide a purification method capable of recovering ruminocumylbenzenes with a high recovery rate.

Summary of the Invention The first aspect of the present invention is a method for purifying bis(p-7 minocumyl)benzenes by purifying low-purity bis(p-7 minocumyl)benzenes using an alkylbenzene having 7 to 13 carbon atoms as a solvent. It is characterized by crystallization.

In addition, in the second aspect of the method for purifying bis(p-aminocumyl)benzenes according to the present invention, low-purity bis(p-aminocumyl)benzenes are mixed with alkylbenzenes having 7 to 13 carbon atoms and alkylbenzenes having 7 to 13 carbon atoms. It is characterized by crystallization using a mixed solvent with aliphatic hydrocarbons.

In the present invention, when refining bis(p-aminocumyl)benzenes, alkylbenzenes having 7 to 13 carbon atoms are used as a crystallization solvent, or alkylbenzenes having 7 to 13 carbon atoms and aliphatic carbonization having 7 to 13 carbon atoms are used. Since bis(aminocumyl)benzenes are crystallized using a mixed solvent with hydrogen as a crystallization solvent, highly purified bis(p-aminocumyl)benzenes can be obtained at a high recovery rate.

DETAILED DESCRIPTION OF THE INVENTION The method for purifying bis(p-aminocumyl)benzenes according to the present invention will be specifically described below.

The bis(aminocumyl)benzenes purified in the present invention are represented by the following general formula [I] (wherein R1,
R2 may be the same or different, and means an alkyl group having 1 to 5 carbon atoms, an amino group, a halogen, a phenyl group, etc.

n is O-4. ) An example of a method for producing bis(p-aminocumyl)benzenes includes the following method.

An aromatic amine represented by the following general formula [II] and an aralkyl alcohol represented by the general formula [I] or an olein obtained by a dehydration reaction of the aralkyl alcohol are combined in the presence of a solid acid catalyst. Obtained by reaction.

(In the formula, R1 and R2 are the same as above, and R3 and R4 are alkyl groups having 1 to 3 carbon atoms.) As the solid acid catalyst used in the above reaction, synthetic zeolite, activated clay, acid clay, silica Alumina, synthetic mica, acidic ion exchange resins, or those obtained by exchanging sodium ions and ions with other metal ions are used.

The reaction is preferably carried out in a large excess of aromatic amines represented by the general formula [II], and usually the aromatic amines represented by the general formula [I[1]
Aromatic amines [I
It is convenient to use [] in a proportion of 4 moles or more, particularly 5 to 20 moles, because the reaction proceeds with good selectivity. In the reaction, a solvent such as xylene, cumene, mesitylene, etc. that does not adversely affect the reaction can also be used.

The reaction temperature is 60-260°C, especially 130-210'C
A range of is appropriate. The reaction time may be selected so that the reaction rate of the aralkyl alcohol or the corresponding olefin expressed by the general formula [ml] is approximately 100%, and may be selected as appropriate depending on the type of catalyst, reaction temperature, reaction method, etc. Just set it.

To isolate bis(p-aminocumyl)benzenes from the reaction mixture, after separating the catalyst from the reaction mixture, unreacted aromatic amines represented by general formula [II], a solvent used as the case may be, etc. A method is used in which the catalyst is removed using a lid, or a method in which the reaction mixture is cooled after separating the catalyst.

Since the bis(p-7 minocumyl)benzenes thus obtained are crude crystals with low purity, they are purified by the purification method according to the present invention.

In the present invention, when bis(p-aminocumyl)benzenes are purified, alkylbenzenes having 7 to 13 carbon atoms are used as crystallization solvents, and alkylbenzenes having 7 to 13 carbon atoms and alkylbenzenes having 7 to 13 carbon atoms are used as crystallization solvents. A mixed solvent with aliphatic hydrocarbons can be used.

If the number of carbon atoms in the alkylbenzenes used as the crystallization solvent is 14 or more, the solubility of the bis(p-aminocumyl)benzenes in the solvent decreases, and it becomes difficult to volatilize and remove the dinuclear solvent after the crystallization operation. Therefore, it is undesirable.

Specifically, such alkylbenzenes having 7 to 13 carbon atoms include toluene, ethyltoluene, xylene, cumene, trimethylbenzene, diethylbenzene, dimethylethylbenzene, tetramethylbenzene, n-butylbenzene, isobutylbenzene, sec- Pulbenzene, tert-butylbenzene, isoamylbenzene, diimpyrbenzene, or a mixture thereof can be used.

Moreover, as the aliphatic hydrocarbon used together with the above alkylbenzenes, those having 7 to 13 carbon atoms can be suitably used. Aliphatic hydrocarbons with 1 to 4 carbon atoms cannot be used as crystallization solvents because they are gases at room temperature, and aliphatic hydrocarbons with 5 to 6 carbon atoms have a different specific gravity from alkylbenzenes and may cause phase separation. Therefore, it is usually not preferable, but it is okay to mix and use them to the extent that they do not interfere with the operation. Further, if the number of carbon atoms is 14 or more, it is not preferable because the binuclear solvent after the crystallization operation is volatilized and difficult to remove.

In the present invention, when a mixed solvent of alkylbenbins and aliphatic hydrocarbons is used as a crystallization solvent, bis(p-
Aminocumyl> This is preferred because benzenes are recovered with high purity and high recovery rate. In this case, it is preferable that the alkylbenzenes and the aliphatic hydrocarbons have no difference in specific gravity from each other, and the mixing ratio is usually 0, expressed as a weight ratio of the alkylbenzenes to the aliphatic hydrocarbons. It is in the range of .25 to 5.

Bis(p-aminocumyl) using such a crystallization solvent
The crystallization operation of benzenes is carried out according to a conventional method, and the crude product bis(
5 to 40 parts by weight of benzenes (aminocumyl) were added, and the solvent was heated to a temperature of 40 to 150°C to dissolve the benzenes, and the resulting solution was then cooled to about room temperature to dissolve bis(p This is carried out by crystallizing bis(p-aminocumyl)benzenes. In this way, purified crystals of bis(p-aminocumyl)benzenes are obtained, and by repeating this crystallization operation, further bis(p-aminocumyl)benzenes are obtained.
aminocumyl) can increase the purity of benzenes.

Effects of the Invention In the present invention, when bis(p-aminocumyl)benzenes are purified, alkylbenzenes having 7 to 13 carbon atoms are used as a crystallization solvent, or alkylbenzenes having 7 to 13 carbon atoms and alkylbenzenes having 7 to 13 carbon atoms are purified. Bis(p-aminocumyl) was prepared using a mixed solvent with aliphatic hydrocarbons as a crystallization solvent.
Since benzenes are crystallized, high purity bis(p-
Aminocumyl>Bempines can be obtained with high recovery rate.

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

Example 1 The catalyst is removed by filtration from the reaction product obtained by reacting α,α°-dihydroxy-1,3-diisopropylbenzene and aniline in the presence of a solid acid catalyst, and unreacted aniline is removed using a vacuum lid. Part of the crude product 1,3-bis(aminocumyl)benzene (purity 85%>200) is 1d.

40% of this 1,3-bis(p-aminocumyl)benzene
After adding CI to toluene and heating to 90'C and mixing, the temperature was lowered to room temperature, and a white powder crystallized. After leaving it at room temperature for about 1 hour, it was filtered under weight and the powder was dried to obtain 1,3-his(p-aminocumyl).
A value of 8.60 was obtained. Analysis using Gas Chroma 1-Graphie showed that the purity was 99.0%. Further, the melting point of this was measured using DSC and was found to be 114°C. Table 1 also shows the solubility of 1,3-bis(p-aminocumyl)benzene in solvents.

Examples 2 to 12 Crude 1,3-bis(p-7 minocumyl)benzene obtained in the same manner as in Example 1 was purified by crystallization using various crystallization solvents shown in Table 1.

Table 1 shows the purity, recovery rate, and crystal shape of the purified product obtained.

Comparative Examples 1 to 8 In the same manner as in Example 1, a crude product of 1,3-bis(p-aminocumyl)benzene was purified by a crystallization operation using various crystallization solvents shown in Table 1.

Table 1 shows the purity, recovery rate, and crystal shape of the purified product obtained.

Examples 13 to 19 The catalyst was removed by filtration from the reaction product obtained by reacting diisopropenylbenzene and aniline in the presence of a solid acid catalyst, and unreacted aniline was removed using a vacuum lid.
4-bis(p-aminocumyl)benzenes (purity 89%
) was obtained. This 1°4-bis(aminocumyl)benzene was purified by crystallization operations from various crystallization solvents shown in Table 2.

Table 2 shows the purity, recovery rate, and crystal shape of the purified product obtained.

Comparative Examples 9 to 11 The 1,4-bis(aminocumyl)benzenes obtained in Examples 13 to 19 were purified by crystallization operations from various crystallization solvents shown in Table 2.

The results are shown in Table 2.

Daionisou - 2Dan2LYU diisopropenylbenzene and 2,6-xylidine are reacted in the presence of a solid acid catalyst, and the catalyst is removed by filtration from the reaction product, and unreacted 2, 6-xylidine was removed by vacuum distillation to obtain 1,4-bis(3,5-dimethyl-4
-Aminocumyl)benzene (purity 88%) crude product was obtained. This 1,4-bis(3,5-dimethyl-4-aminocumyl)benzene was purified by crystallization operations from various crystallization solvents shown in Table 3.

Table 3 shows the purity, recovery rate, and crystal shape of the purified product obtained by 1q.
Shown below.

Examples 23-24 The catalyst is removed by filtration from the reaction product obtained by reacting p-diisopropenylbenzene and 0-phenylenediamine in the presence of a solid acid catalyst, and unreacted 0-phenylenediamine is removed under reduced pressure. The crude product of 1,4-bis(3,4-diaminocumyl)benzene (M74%) was obtained by distillation.

This 1,4-bis(3,4-diaminocumyl)benzene was purified by crystallization operations from various crystallization solvents shown in Table 4.

Table 4 shows the purity, recovery rate, and crystal shape of the purified product obtained.

Claims (5)

[Claims] (1) A method for purifying bis(p-aminocumyl)benzenes, which comprises crystallizing low-purity bis(p-aminocumyl)benzenes using an alkylbenzene having 7 to 13 carbon atoms as a solvent. (2) Alkylbenzenes having 7 to 13 carbon atoms include toluene, ethyltoluene, xylene, cumene, trimethylbenzene, diethylbenzene, dimethylethylbenzene,
Claim 1 which is tetramethylbenzene, n-butylbenzene, isobutylbenzene, sec-butylbenzene, tert-butylbenzene, isoamylbenzene, diisopropylbenzene or a mixture thereof.
The method described in section. (3) Low-purity bis(p-aminocumyl)benzenes are combined with alkylbenzenes having 7 to 13 carbon atoms and 7 to 1 carbon atoms.
3. A method for purifying bis(p-aminocumyl)benzenes, which comprises crystallizing using a mixed solvent with an aliphatic hydrocarbon. (4) Alkylbenzenes having 7 to 13 carbon atoms include toluene, ethyltoluene, xylene, cumene, trimethylbenzene, diethylbenzene, dimethylethylbenzene,
Tetramethylbenzene, n-butylbenzene, isobutylbenzene, sec-butylbenzene, tert-butylbenzene, isoamylbenzene, diisopropylbenzene, or a mixture thereof, and aliphatic hydrocarbons having 7 to 13 carbon atoms include heptane, octane, 4. The method according to claim 3, wherein nonane, decane, undecane, dodecane, tridecane or a mixture thereof is used. (5) The method according to claim 3, wherein the mixing ratio expressed in weight ratio of the alkylbenzenes to the aliphatic hydrocarbons is 0.25 to 5.