JPH04288041A - Production of aromatic carboxylic acid aryl ester - Google Patents

Abstract

PURPOSE:To produce an aromatic carboxylic acid aryl ester in high selectivity by esterifying an aromatic dicarboxylic acid with a phenolic compound in the presence of a distannoxane derivative and antimony or its compound. CONSTITUTION:An aromatic carboxylic acid aryl ester (especially diphenyl terephthalate, etc.) can be produced in high reaction rate and selectivity in high purity and in an easily purifiable state by reacting a phenolic compound (especially phenol, etc.) with an aromatic carboxylic acid (especially terephthalic acid, etc.) in the presence of a distannoxane derivative (e.g. the compound of formula I or formula II) and antimony or its compound (especially preferably antimony trioxide) as the catalysts.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for producing an aromatic carboxylic acid aryl ester, and more specifically, a method for producing the desired aromatic carboxylic acid aryl ester at a high reaction rate and with high selectivity while suppressing side reactions. Relating to a method of manufacturing.

0002

[Prior art] Aromatic carboxylic acid aryl ester is
Dyes, high molecular weight polymers, ultraviolet absorbers, synthetic resin stabilizers,
It is useful as a coloring agent and an intermediate in the production of pharmaceuticals, etc. For example, aromatic dicarboxylic acid diphenyl esters such as diphenyl terephthalate are important as raw materials for producing polyester resins.

[0003] Conventionally, as a method for producing such an aromatic carboxylic acid aryl ester, there is a method disclosed in Japanese Patent Publication No. 46-2372.
As described in No. 4, a method is known in which oxides, hydroxides, oxyacids, carboxylates, halides, phenoxides, alkoxides, etc. of metals such as tin, manganese, and cobalt are used as catalysts. Also, JP-A-52
As described in Publication No.-71433, silica,
Methods using solid acids such as alumina, acid clay, and zeolite as catalysts are also known.

Furthermore, Japanese Patent Publication No. 52-501031 proposes a two-step reaction method using tin oxide as a catalyst. Furthermore, JP-A-62-87248 proposes an esterification catalyst made of a distanoxane derivative, while JP-A-48-19534 proposes a catalyst made of antimony oxide. However, according to the conventionally known methods described above,
In either case, since the reaction is carried out at high temperatures, side reactions such as Fries rearrangement are likely to occur after esterification, and thus the selectivity of the desired aromatic carboxylic acid aryl ester is low. In particular, when producing diaryl esters of aromatic dicarboxylic acids, the diester selectivity is low.

[0005]

OBJECTS TO BE SOLVED BY THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional production of aromatic carboxylic acid aryl esters. An object of the present invention is to provide a method for producing an aromatic carboxylic acid aryl ester.

In particular, an object of the present invention is to provide a method for producing diesters with high selectivity by esterifying aromatic dicarboxylic acids with phenols.

[0007]

[Means for Solving the Problems] A method for producing an aromatic carboxylic acid aryl ester according to the present invention is a method for producing an aromatic carboxylic acid aryl ester by reacting a phenol with an aromatic carboxylic acid. It is characterized by the coexistence of antimony or a compound thereof.

The phenols used in the method of the present invention are represented by the general formula (I) Ar-(OH)m (wherein Ar represents an aromatic group and m represents an integer of 1 or more). Examples of the aromatic group Ar include a benzene ring, a naphthalene ring, an anthracene ring, and a tetralin ring which may have a substituent. When the aromatic group has a substituent, examples of the substituent include a halogen atom, a nitro group, an alkyl group, an alkoxy group, a phenoxy group, an amino group, an aryl group, an alkoxycarbonyl group, a phenoxycarbonyl group, a carboxyl group, etc. can be mentioned. m is preferably
1 or 2.

Therefore, specific examples of the above-mentioned phenols include phenol, o-, m- or p-
-cresol, catechol, resorcinol, hydroquinone, pyrogallol, o-, m- or p-chlorophenol, 3,5- or 2,5-xylenol, m- or p-
Mention may be made of aminophenol, o-, m- or p-methoxyphenol, α- or β-naphthol, 2,6-naphthalenediol, α- or β-anthrol, dihydroxydiphenyl ether, bisphenol A, biphenol and the like.

These phenols are used in a molar ratio of 0.1 to 100, preferably 1 to 50, relative to the aromatic carboxylic acid described below. These phenols may be used alone or as a mixture of two or more, if necessary. The aromatic carboxylic acid used in the method of the present invention has the general formula (II
)Ar'-(COOH)n (In the formula, Ar' represents an aromatic group, and n represents a positive number of 1 or more.) Examples of the aromatic group Ar' include a benzene ring, a naphthalene ring, an anthracene ring, a tetralin ring, etc. which may have a substituent, as described above. When the aromatic group has a substituent, examples of the substituent include a halogen atom, a nitro group, an alkyl group, an alkoxy group, a phenoxy group, an amino group, an aryl group, an alkoxycarbonyl group, a phenoxycarbonyl group, a carboxyl group, etc. can be mentioned. n is preferably 1 or 2.

[0011] Therefore, specific examples of such aromatic carboxylic acids include benzoic acid, hydroxybenzoic acid,
p-aminobenzoic acid, 2,4-dichlorobenzoic acid, p-
Examples include t-butylbenzoic acid, benzoylbenzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, biphenyl dicarboxylic acid, α-naphthoic acid, β-naphthoic acid, naphthalene dicarboxylic acid, anthranilic acid, and the like. These possible acid anhydrides and salts can also be used as aromatic carboxylic acids.

These aromatic carboxylic acids may be used alone or as a mixture of two or more. In the method of the present invention, the reaction is carried out in the presence of antimony or a compound thereof together with a distanoxane derivative as a catalyst. Here, the above distanoxa

[0013] The derivatives preferably have the general formula (III
)

[Chemical formula 1]

(In the formula, Ra, Rb, Rc and Rd each independently represent an alkyl group or an aryl group, and Xa and Xb each independently represent a hydroxy group, an alkoxy group or an aryloxy group.) . In the above general formula (III), Ra, Rb, Rc and Rd are
Each independently represents an alkyl group or an aryl group, preferably an alkyl group having 1 to 12 carbon atoms or 6 to 1 carbon atoms.
2 is an aryl group.

[0015] Therefore, as specific examples of such distanoxane derivatives, for example,

[0016]

[Case 2]

[0017]

[Chemical formula 3]

[0018] etc. can be mentioned. In the method of the present invention, the distanoxane derivative as described above is used in a molar ratio of 1 x 10 to the -5 power to 1 x 10, preferably 1 x 10 to the -4 power to 1 x 10
It is used in the range of -2. In the method of the present invention, the reaction between an aromatic carboxylic acid and a phenol is carried out in the presence of antimony or a compound thereof together with the above-mentioned distanoxane derivative. Examples of the antimony compound include antimony dioxide, antimony trioxide, antimony pentoxide, antimony chloride, antimony fluoride, antimony sulfide, and potassium antimonate. These can be used alone or as a mixture of two or more. Among these, antimony trioxide is particularly preferably used in the present invention.

These antimony or antimony compounds can be used as they are, or can be supported on a carrier. Examples of such carriers include carbon, alumina, zeolite, graphite, silica, magnesium oxide, clay, barium sulfate, calcium carbonate, and the like. In the present invention, such antimony or antimony compound is used in a molar ratio of 1 x 10 to the -10th power to 1 x to 10 to the -3 power with respect to the aromatic carboxylic acid.

In the method of the present invention, the reaction is usually carried out without a solvent, but an organic solvent may also be used. The organic solvent is preferably one that is immiscible with water and can form an azeotrope with water. Examples of such organic solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene, hexane, octane, decane,
Examples include aliphatic or alicyclic hydrocarbons such as cyclohexane and decalin, and aromatic halides such as chlorobenzene, dichlorobenzene and bromobenzene.

[0021] The reaction is usually carried out at a temperature of 100 to 400°C, preferably 150 to 350°C. The reaction time is usually 10 minutes to 40 hours. The pressure during the reaction may be under reduced pressure or under increased pressure.

[0022]

Effects of the Invention According to the method of the present invention, an aromatic carboxylic acid aryl ester is produced by reacting a phenol with an aromatic carboxylic acid in the presence of a distanoxane derivative and antimony or its compound. The aromatic carboxylic acid aryl ester can be obtained at high reaction rate and high selectivity, and the obtained aromatic dicarboxylic acid has high purity and can be easily purified.

[0023]

[Examples] The present invention will be explained below with reference to Examples.
The present invention is not limited in any way by these Examples. Example 1

2.5 g of terephthalic acid, 21 g of phenol.
4g,

[C4]

Distanoxane derivative represented by 0.0
25 g of antimony trioxide and 10 mg of antimony trioxide were placed in a 50 ml autoclave, and the reaction was carried out at 260° C. for 2 hours under pressure. After the reaction was completed, the amounts of terephthalic acid (TA), monophenyl terephthalate (MPT), and diphenyl terephthalate (DPT) in the reaction solution were analyzed by liquid chromatography, and the reaction results were determined from the following calculation formula. The results are shown in Table 1.

Terephthalic acid reaction rate (mol%)

[Math 1]

Diphenyl terephthalate selectivity (mol%
)

[Math 2]

Carboxyl group reaction rate (mol%)

[Math 3]

In the above formula, [TA], [MPT] and [DPT] respectively represent the number of moles of terephthalic acid, monophenyl terephthalate and diphenyl terephthalate in the reaction solution. Comparative Example 1 In Example 1, 10 m of antimony trioxide was used as a catalyst.
The reaction was carried out in the same manner as in Example 1 except that only g was used. The reaction results are shown in Table 1. Comparative Example 2 A reaction was carried out in the same manner as in Example 1, except that only 0.025 g of the same distanoxane derivative as in Example 1 was used as a catalyst. The reaction results are shown in Table 1. Example 2 1 g of terephthalic acid, 9 g of phenol, 10 mg of the same distanoxane derivative as in Example 1, and 4 m of antimony trioxide
g into an autoclave with a capacity of 50 ml, and heated at 280℃.
The reaction was carried out under pressure for 3 hours.

After the reaction was completed, the reaction results were determined in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 3 In Example 1, 4 mg of antimony trioxide was used as a catalyst.
The reaction was carried out in the same manner as in Example 2, except that only The reaction results are shown in Table 1. Comparative Example 4 Example 2 except that only 10 mg of the same distanoxane derivative as in Example 1 was used as a catalyst in Example 1.
The reaction was carried out in the same manner. The reaction results are shown in Table 1.

[0031]

[Table 1]

Claims (4)

[Claims] [Claim 1] A method for producing an aromatic carboxylic acid aryl ester by reacting a phenol with an aromatic carboxylic acid, which comprises coexisting antimony or a compound thereof with a distanoxane derivative. Method for producing esters. 2. The method for producing an aromatic carboxylic acid aryl ester according to claim 1, wherein the aromatic dicarboxylic acid is terephthalic acid. 3. The method for producing an aromatic carboxylic acid aryl ester according to claim 1, wherein the phenol is phenol. 4. The method for producing an aromatic carboxylic acid aryl ester according to claim 1, wherein the antimony compound is antimony trioxide.