JPH0514690B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aralkyl monosubstituted polyhydric phenols. More specifically, the present invention relates to a method for producing aralkyl monosubstituted polyhydric phenols in high yield. Aralkyl monosubstituted polyhydric phenols are compounds useful as epoxin resin raw materials, phenolic resin modifiers, polyester raw materials, stabilizers, and color developers. Conventionally, several studies have been made regarding the synthesis of these aralkyl monosubstituted polyhydric phenols. For example, J.Org.Chem., 17 243
248 (1951), the results of research on the aralkylation reaction conditions of phenols and styrene are reported. A sulfuric acid catalyst is useful as a catalyst;
In order to increase the yield, styrene is used diluted with a solvent such as toluene, but aralkyl di-substituted products are often produced, and the yield of aralkyl mono-substituted products is not high. Additionally, additional tests revealed that dimerization of styrene compounds progressed considerably. In addition, US Patent No. 2,247,404 describes a method of reacting polyhydric phenols near their melting point using concentrated hydrochloric acid as a catalyst, but when this method was repeated, the yield of aralkyl monosubstituted product was The dimerization reaction of aromatic unsaturated compounds mainly occurred. For example, when α-methylstyrene is used, 1,3,3
It was found that -trimethyl-1-phenylindane was mainly produced, and only a very small amount of the target aralkyl monosubstituted product was obtained. Also, Tokukai Akira
In the specification of No. 58-140085, using a phosphoric acid catalyst,
A method of reacting polyhydric phenols with aromatic unsaturated compounds at a reaction temperature of 100 to 170°C has been shown, but additional tests have shown that even with this method, dimerization of aromatic unsaturated compounds mainly occurs. It became clear that the desired aralkyl monosubstituted product could not be obtained in good yield. The present inventors have improved the above-mentioned drawbacks and achieved high yield,
As a result of intensive studies on a method for producing highly pure aralkyl monosubstituted polyhydric phenols, we found that when an aqueous solution of polyhydric phenols and an aromatic unsaturated compound are brought into contact with the presence of an acid catalyst, 2 of the aromatic unsaturated compounds
It has been found that quantification hardly occurs and the desired aralkyl monosubstituted product can be obtained in extremely good yield, leading to the present invention. That is, the present invention provides general formula (A) (However, R ₁ : -H group, -OH group, halogen group, alkyl group having 1 to 4 carbon atoms) and the general formula (B) (However, R ₂ : -H group, alkyl group having 1 to 4 carbon atoms R ₃ , R ₄ : -H group, -OH group, halogen group, alkyl group having 1 to 4 carbon atoms) By reacting with at least one saturated compound, the following general formula (C) (However, R ₁ , R ₂ , R ₃ , and R ₄ are the same as defined above.) When producing an aralkyl monosubstituted polyhydric phenol represented by the formula (A), an acid catalyst is used, and the general formula (A)
This is a method for producing aralkyl monosubstituted polyhydric phenols, which is characterized by contacting an aqueous solution of polyhydric phenols represented by the formula with an aromatic unsaturated compound. According to the method of the present invention, aralkyl disubstituted products and dimers of aromatic unsaturated compounds are hardly produced, and aralkyl monosubstituted products can be produced in high yield and with high purity. Polyhydric phenols in the present invention include catechol, 4-methylcatechol, 6-methylcatechol, 4-tert-butylcatechol, resorcin, 4-methyl-resorcin, 2-methyl-resorcin, 5-methyl-resorcin. , 4-chlorresorcinol, 2-methyl-hydroquinone, 2-
Examples include tert-butylhydroquinone, 2-chloro-hydroquinone, hydroquinone, pyrogallol, and particularly preferably catechol, resorcinol, and hydroquinone. On the other hand, specific examples of aromatic unsaturated compounds represented by the general formula (B) include sterene, α-methylstyrene, β-methylstyrene, dimethylstyrene, dimethyl-α-methylstyrene, and p-methylstyrene. , p-methyl-α-methylstyrene, p
-Chlorstyrene, p-chloro-α-methylstyrene, p-hydroxy-styrene, m-hydroxystyrene, m-hydroxyisopropenylbenzene, 2,4-dihydroxystyrene, 2,4-
An example is dihydroxyisopropenylstyrene. The amount of the polyhydric phenols and aromatic unsaturated compound to be used is preferably 0.5 to 1 mol of the aromatic unsaturated compound relative to the polyhydric phenol. The acid catalyst used in the present invention may be any commonly used acid catalyst, such as sulfuric acid, hydrochloric acid, phosphoric acid, etc. The amount of acid is preferably 2 to 30 parts by weight per 100 parts of water, and if it is less than 2 parts by weight, the reaction rate is low;
In addition, if it exceeds 30 parts by weight, aralkyl di-substituted product,
and dimers of aromatic unsaturated compounds are produced, which is undesirable. Alternatively, a feature of the method of the present invention is that polyhydric phenols are used in the form of an aqueous solution dissolved in water, and the amount used varies depending on the polyhydric phenols used, but in general, It is preferably 20 to 200 parts by weight per 100 parts by weight of water. The reaction concentration is usually preferably carried out in a range of 40 to 90°C, particularly preferably 60 to 80°C. In the aralkylation reaction, polyhydric phenols,
It is preferable to gradually add the aromatic unsaturated compound represented by the general formula (B) to the acid catalyst mixed aqueous solution.
The addition time is usually preferably 1 to 8 hours, particularly preferably 1 to 4 hours. After adding the aromatic unsaturated compound, it is preferable to carry out a thermal formation reaction for 2 to 4 hours. After the reaction is completed, the reaction solution is separated into an oil layer and an aqueous layer, and the aqueous layer is repeatedly used for the next reaction. On the other hand, an oil layer solidifies when cooled after washing with hot water, but can be dissolved in an organic solvent and recrystallized without cooling after washing with hot water. The aralkyl monosubstituted polyhydric phenols obtained in this way have high purity,
As mentioned above, it can be used for various purposes. The present invention will be explained in detail below using Examples. Example 1 A glass reactor equipped with a stirrer, a thermometer, and a condenser was charged with 100 parts by weight of resorcinol, 5 parts by weight of concentrated sulfuric acid, and 100 parts by weight of water, and heated to 80°C.
100 parts by weight of α-methylstyrene was added dropwise over 4 hours, and after the addition, the reaction was allowed to proceed at the same temperature for 3 hours. After the reaction was completed, the reaction solution was allowed to stand still, divided into two layers, and the lower oil layer was separated, washed with warm water, and then recrystallized from a toluene solvent. the product obtained The yield was 184 parts by weight (yield 95.3%), and the purity was 99.9%. Comparative Example 1 Using the same reactor as in Example 1, resorcinol
100 parts by weight of concentrated sulfuric acid and 5 parts by weight of concentrated sulfuric acid were charged, heated to 120°C, and 100 parts by weight of α-methylstyrene was added dropwise over 4 hours. After the dropwise addition, the mixture was reacted at the same temperature for 8 hours. After the reaction was completed, the oil layer obtained by washing the reaction solution with warm water was recrystallized from a toluene solvent, and the yield of the obtained crystals was 40 parts by weight, and the purity was as low as 92%. Analysis of the reaction solution by gas chromatography revealed that it was a dimer of α-methylstyrene. A large amount of 1,3,3-trimethyl-1-phenylindane was produced. Furthermore, as a result of GPC analysis, a large amount of octamer component was also observed. Example 2 The reaction was carried out in the same manner as in Example 1, using catechol instead of resorcinol in Example 1, and the obtained oil layer was recrystallized from a toluene solvent. The yield was 178 g (92.2% yield), and the purity was 99.9%. Comparative Example 2 Similar to Comparative Example 1, catechol was used instead of resorcinol, and the amount of preparation was the same as Comparative Example 1.
Heated to ˜150° C. and added α-methylsterene, also as in Comparative Example 1. After the reaction was completed, the oil layer obtained by washing the reaction solution with hot water was recrystallized in a toluene solvent, and the yield of the obtained crystals was 25 parts by weight, and the purity was as low as 90%. When the reaction solution was analyzed by gas chromatography, it was found that 1,3,3-trimethyl-1-
A large amount of phenylindane was observed, as well as a considerable amount of unknown components. Furthermore, as a result of GPC analysis, the formation of many trimers based on aralkyl di-substituted products was also observed. Example 3 Hydroquinone was used in place of resorcinol in Example 1, and a reaction was carried out under the same reaction conditions as in Example 1. The obtained oil layer was recrystallized from a toluene solvent, and the obtained crystals were

The yield of [Formula] was 174 g (90% yield), and the purity was 99.8%. Comparative Example 3 Similar to Comparative Example 1, hydroquinone was used instead of resorcinol, and concentrated hydrochloric acid was used instead of concentrated sulfuric acid.
and α-methylstyrene was added, again in the same manner as in Comparative Example 1. After the reaction solution was finished, the oil layer obtained by washing the reaction solution with warm water was recrystallized using a toluene solvent, and the yield of the obtained crystals was 30 parts by weight, and the purity was as low as 87%. Ta. When the reaction solution was analyzed by gas chromatography in the same manner as Comparative Example-1 and Comparative Example-2, a large amount of 1,3,3-trimethyl-1-phenylindane was detected, as well as a large amount of unknown components. . or,
From the results of GPC analysis, a large amount of trimers based on aralkyl di-substituted products was observed.

Claims (1)

[Claims] 1 General formula (A) (However, R ₁ : -H group, OH group, halogen group, or alkyl group having 1 to 4 carbon atoms) and the general formula (B) (However, R ₂ : -H group or alkyl group having 1 to 4 carbon atoms; R ₃ , R ₅ : -H group, -OH group, halogen group, or alkyl group having 1 to 4 carbon atoms) The following general formula (C) is obtained by reacting at least one unsaturated compound with an acid catalyst. (However, R ₁ , R ₂ , R ₃ and R ₄ are the same as defined above.) In producing the aralkyl monosubstituted polyhydric phenols represented by the formula (A), 1. A method for producing aralkyl monosubstituted polyhydric phenols, which comprises contacting an aqueous solution with an aromatic unsaturated compound represented by the general formula (B). 2. The method for producing an aralkyl monosubstituted polyphenol according to claim 1, wherein the polyvalent phenol represented by the general formula (A) is catechol, hydroquinone, or resorcinol.