JP4586504B2 - Method for producing aromatic ester compound - Google Patents

Description

The present invention relates to a manufacturing method of high-yield aromatic ester compound by esterification reaction of a phenol and a carboxylic acid with a specific esterification catalysts.

  Aromatic ester compounds have properties such as a high refractive index, low water absorption, and high heat resistance, and have a wide variety of uses such as paints, plastics, and optical materials, taking advantage of these properties. In general, as a method for producing an ester compound, a method in which a carboxylic acid and an alcohol are reacted in the presence of an acid catalyst is well known. However, it is also known that the dehydration esterification reaction between phenols and carboxylic acids is difficult to obtain the corresponding ester compounds in high yield due to the high acidity and equilibrium problems of the phenols. .

The following are known methods for obtaining aromatic ester compounds.
For example, as an example using an acid halide having a higher reactivity than carboxylic acid, a method of reacting an acid halide with a phenol in the presence of an organic base has been proposed (see, for example, Patent Document 1). However, acid halides are expensive and difficult to handle, and a large amount of salt is by-produced. Similarly, a reaction between a highly active acid anhydride and a phenol has also been proposed, but the acid anhydride is also difficult to handle and has a problem that a large amount of waste is generated (for example, see Patent Document 2). .

  A method of obtaining an aromatic ester compound from phenols and (meth) acrylic acid using sulfuric acid or sulfuric acid and boric acid as a catalyst has also been proposed, but the reaction rate is low and the sulfonation of phenols, etc. There is also a problem that the side reaction tends to occur (see, for example, Patent Document 3). In addition, a method using an ion exchange resin as a catalyst has been proposed. However, this catalyst is expensive, and the reaction time is long and the reaction rate is not sufficient (see, for example, Patent Document 4). Furthermore, an aromatic ester compound is obtained using a tin compound (for example, see Patent Document 5), a lead compound (for example, see Patent Document 6), metal tin and / or metal lead (for example, see Patent Document 7) as a catalyst. Although methods are also disclosed, all have low reaction rates and are difficult to separate and purify such as catalyst removal.

  On the other hand, a method using an organic sulfonic acid such as p-toluenesulfonic acid as a catalyst for the esterification reaction of a novolak-type phenol resin and an aromatic carboxylic acid such as benzoic acid has also been proposed (see, for example, Patent Document 8). ) However, the reaction rate is not sufficient.

  Further, as a method for producing an ester compound using a super strong acid as a catalyst, a method for producing an unsaturated carboxylic acid ester by reacting an alcohol and an unsaturated carboxylic acid using a solid super strong acid containing zirconium has been proposed (for example, , See Patent Document 9). However, such alcohols are aliphatic alcohols, and no mention or suggestion is made regarding the reaction between phenols and carboxylic acids.

Furthermore, a method for producing an unsaturated carboxylic acid ester in the liquid phase using a heteropolyacid as a catalyst has also been proposed (see, for example, Patent Document 10). However, such alcohols are aliphatic alcohols, and no mention or suggestion is made regarding the reaction between phenols and carboxylic acids.
A method for producing an unsaturated carboxylic acid ester using an acid salt of a heteropolyacid is known (for example, see Patent Document 11).

  In addition, a method for producing an ester condensate using a tetravalent hafnium compound or a tetravalent zirconium compound as a catalyst has been proposed (see, for example, Patent Documents 12 to 14). However, such ester condensate is a condensate of aliphatic alcohol or thiol and carboxylic acid, and no mention or suggestion is made about the reaction between phenols and carboxylic acid.

Japanese Patent Publication No. 50-23019 (Claims) JP 2000-191590 A (Claims) JP-A-60-258144 (Claims) Japanese Patent Laid-Open No. 62-132840 (Claims) JP-A-2-115141 (Claims) Japanese Patent Laid-Open No. 2-117645 (Claims) Japanese Patent Laid-Open No. 2-12449 (Claims) JP-A-9-221531 (Claims) JP-A-11-152249 (Claims) JP-A-4-250853 (Claims) JP-A-11-152248 (Claims) JP-A-2002-121170 (Claims) JP 2004-83531 A (Claims) JP2003-291471A (Claims)

  The present invention provides a method for efficiently producing a corresponding aromatic ester compound from phenols and carboxylic acid in a high yield, overcoming the drawbacks of the conventional methods for producing aromatic esters. .

  The present inventor has found that the above problems can be solved by using a heteropolyacid carrier or a heteropolyacid salt carrier as an esterification catalyst, and has completed the present invention. That is, the catalyst is provided as an esterification catalyst, and an ester compound production method using the catalyst is provided.

  According to the present invention, an aromatic ester compound can be obtained from a phenol and a carboxylic acid with a high yield in a short reaction. Furthermore, since there are few by-products and wastes at the time of aromatic ester compound manufacture, it is a manufacturing method in consideration of environmental problems.

  The catalyst used in the method for producing an aromatic ester compound of the present invention is synthesized from a heteropolyacid or a salt thereof and an inorganic carrier. This will be described in detail below.

Heteropolyacid or salt thereof The heteropolyacid used in the synthesis of the catalyst of the present invention is at least one oxide selected from the group consisting of Mo, W, Nb and V, and P, Si, As, Ge , B, Ti, Co, and Ce are obtained by condensation with at least one oxyacid selected from the group consisting of. The ratio of oxide to oxyacid is 2.5-12. As the heteropolyacid, not only a monomer but also a polymer such as a dimer or a trimer, or a mixed heteropolyacid in which two or more of each atom are coordinated can be used. Moreover, it may be a partially or completely neutralized salt of these heteropolyacids such as sodium, potassium, cobalt, nickel, manganese, copper, cesium, or ammonium (combining these partially or completely neutralized salts together). Sometimes simply called salt).
Specific examples of these heteropolyacids include phosphomolybdic acid, phosphotungstic acid, phosphomolybdotungstic acid, phosphomolybdovanadic acid, phosphomolybdotungstovanadic acid, phosphotungstovanadic acid, phosphomolybdniobic acid, and tungsten carbide. Acid, silicomolybdic acid, silico-ribbed tungstic acid, silico-ribbed tungstovanadic acid, germanium tungstic acid, borotungstic acid, boromolybdic acid, boromolybdotungstic acid, boromolybdovanadic acid, boromolybdo-tungstovanadic acid, And cobalt molybdic acid and the like, and the above-mentioned salts thereof.
As the heteropolyacid used in the synthesis of the catalyst of the present invention, an acid and a partially neutralized salt are preferable, and an acid is particularly preferable.
As the heteropolyacid used in the synthesis of the catalyst of the present invention, these may be used alone or in combination of two or more. As the heteropolyacid used in the present invention, the metal element constituting the oxide is more preferably molybdenum and / or tungsten, and the oxyacid is more preferably phosphorus or silicon. That is, phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, and / or silicomolybdic acid are suitable.

Inorganic support Examples of the inorganic support for supporting the heteropolyacid and / or heteropolyacid salt used in the synthesis of the catalyst of the present invention include powdery, granular, and particulate solids, preferably granular or particulate solids. Is. As the inorganic carrier, a porous oxide or activated carbon is preferable. Specific examples of the oxide carrier include SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, and BaO, or a mixture thereof. Examples of the mixture include SiO ₂ —MgO, SiO ₂ —Al ₂ O ₃ , and SiO ₂ —TiO ₂ . Among these, those containing at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ as a main component are preferable.
The method for supporting the heteropolyacid used in the present invention may be a conventional method (see, for example, Chem. Lett., 2002, p. 1104, and Catalysts, 1997, 39, 4, p. 292, etc.). .
Specifically, after impregnating an inorganic carrier in an aqueous solution or a methanol solution of a heteropolyacid and / or heteropolyacid salt, it may be fired at about 50 to 400 ° C. The firing temperature is preferably 100 to 350 ° C, more preferably 150 to 300 ° C.

  The supported amount of the heteropolyacid and / or heteropolyacid salt carrier used in the present invention is preferably 3 to 75% by mass, more preferably 5 to 50% by mass. When the supported amount is less than 3% by mass, sufficient acid catalytic ability cannot be exhibited, and when it is more than 75% by mass, it is economically disadvantageous.

○ Phenols Examples of the phenols in the present invention include phenol, p-chlorophenol, 2,3,5-trichlorophenol, pentachlorophenol, pentabromophenol, p-bromophenol, o-methoxyphenol, and p-methoxyphenol. P-benzylphenol, p-phenoxyphenol, o-phenylphenol, p-phenylphenol, p-ethoxyphenol, o-butoxyphenol, p-ethylphenol, m-ethylphenol, o-ethylphenol, p-butylphenol, p-nonylphenol, p-cyclohexylphenol, decylphenol, p-nitrophenol, p-cyanophenol, p-cresol, o-cresol, xylenol, diethylphenol, trimethyl Phenol, catechol, dihydroxybiphenyl, resorcinol, hydroquinone, phloroglucinol, α-naphthol, β-naphthol, dihydroxynaphthalene, bisphenol A, bisphenol F, bisphenol S and the like.

○ The unsaturated aliphatic carboxylic acid in the unsaturated aliphatic carboxylic acids present invention preferably have a monocarboxylic acid, in view of the industrial usefulness, acrylic acid, methacrylic acid, and the polymerization activity of crotonic acid Unsaturated carboxylic acid is preferable, and acrylic acid or methacrylic acid is more preferable. Together with acrylic acid and methacrylic acid, it may be referred to as (meth) acrylic acid.

  In the present invention, the use ratio of phenols and carboxylic acids is preferably such that the molar ratio of the reactive groups is in the range of 1:10 to 10: 1 (phenolic hydroxyl group: carboxyl group), more preferably 1: 5 to 5: 1, particularly preferably 1: 3 to 3: 1. The phenols and carboxylic acids used in excess can be reused after being separated from the aromatic ester compound produced after the reaction.

  The amount of the heteropolyacid and / or heteropolyacid salt in the support used in the present invention is not particularly limited as long as it is an amount used in a usual dehydration esterification reaction. For example, among the phenols or carboxylic acids used in the esterification reaction, the amount of the heteropolyacid and / or heteropolyacid salt is preferably 0.01 to 30 mol%, more preferably 0 with respect to the smaller number of moles of the substrate. 0.05 to 20 mol%.

  The production of the aromatic ester compound using the catalyst of the present invention can be carried out in the same manner as in the conventional esterification reaction. For example, a preferred mode of gas phase or liquid phase reaction can be selected according to the type of aromatic ester compound, the form of the catalyst, the properties of the raw materials, the presence or absence of a solvent, and the like. That is, the reaction temperature is preferably 20 to 200 ° C., more preferably 50 to 180 ° C., and particularly preferably 80 to 150 ° C., although it varies depending on the type of target aromatic ester compound. Further, the reaction time is preferably 0.1 to 30 hours, and particularly preferably 1 to 20 hours.

  Solvents used in the production of aromatic ester compounds include dimethyl sulfoxide; aliphatic hydrocarbon solvents such as hexane, heptane and cyclohexane; and aromatic hydrocarbon solvents such as toluene, xylene and cumene it can. In this esterification reaction, the reaction system may be reduced in pressure, and in the presence of a solvent azeotropic with water such as hexane, heptane, cyclohexane, toluene, xylene and cumene in order to more efficiently remove water. Preferably it is done.

  When an unsaturated carboxylic acid is used as the carboxylic acid, a polymerization inhibitor can be used in combination as long as the object and effects of the present invention are not impaired. Examples of the polymerization inhibitor that can be used in the production of the aromatic ester compound of the present invention include hydroquinone, methoxyhydroquinone, and phenothiazine. The polymerization can also be suppressed by blowing air into the reaction solution.

  As a purification method of the aromatic ester compound after completion of the esterification reaction, filtration, alkaline water washing, considering the physical properties of the product, the type and amount of the raw material, the type and amount of the catalyst, the presence or absence of the solvent, etc. Known purification methods such as water washing, distillation, and crystallization can be appropriately combined.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to an Example, unless the summary is exceeded.

<Example 1>
○ Synthesis of phosphotungstic acid / silica supported catalyst (catalyst A1) Silica gel (Aerosil-300 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 274 m ² / g) was slowly added to the phosphotungstic acid aqueous solution prepared to 0.08 mol / liter and left as it was. It was immersed for 6 hours and filtered. This was dried at 100 ° C. for 12 hours and then heated in air at 250 ° C. for 4 hours to obtain a 20 wt% phosphotungstic acid / silica supported catalyst (referred to as catalyst A1).

<Example 2>
○ Synthesis of phosphotungstic acid / silica-supported catalyst (catalyst A2) Silica gel (Aerosil-300 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 274 m ² / g) was slowly added to the phosphotungstic acid aqueous solution prepared to 0.16 mol / liter and left as it was. It was immersed for 6 hours and filtered. This was dried at 100 ° C. for 12 hours and then heated in air at 250 ° C. for 4 hours to obtain a 40 wt% phosphotungstic acid / silica supported catalyst (referred to as catalyst A2).

<Example 3>
○ Synthesis of phosphotungstic acid / silica-supported catalyst (catalyst B) Silica gel (Aerosil-300 manufactured by Nippon Aerosil, specific surface area: 274 m ² / g) was slowly added to silicotungstic acid aqueous solution prepared to 0.16 mol / liter. It was immersed for 6 hours and filtered. This was dried at 100 ° C. for 12 hours and then heated in air at 250 ° C. for 4 hours to obtain a 40 wt% silicotungstic acid / silica supported catalyst (referred to as catalyst B).

<Example 4>
○ Synthesis of phosphotungstic acid / silica-supported catalyst (catalyst C) Activated carbon (Ajinomoto Fine-Techno Hokuetsu CL-K, specific surface area: 1200 m ² / g or more) was added to the phosphotungstic acid methanol solution prepared to 0.16 mol / liter. Slowly added, soaked for 6 hours and filtered. This was dried at 100 ° C. for 12 hours and then heated in air at 250 ° C. for 4 hours to obtain a 40 wt% phosphotungstic acid / activated carbon supported catalyst (referred to as catalyst C).

<Example 5>
In a 300 ml three-necked flask equipped with a stirrer, a condenser, a water separator (Dean Stark trap) and a thermometer, 14.4 g of the catalyst A1 synthesized in Synthesis Example 1 (containing 1 mmol of phosphotungstic acid), 0.1 mol of phenol, 0.2 mol of acrylic acid, 0.034 g of methoxyhydroquinone, and 150 ml of xylene were charged, and dry air was blown in. This reaction solution was heated and stirred for 3 hours under reflux of xylene while azeotropically dehydrating by-product water. After completion of the reaction, the product was analyzed by gas chromatography, and the yield of acrylic acid phenyl ester relative to phenol was determined. The results are shown in Table 1.

○ Analysis conditions for gas chromatography Column: TC-1 manufactured by GL Sciences
Length: 15m, inner diameter: 0.25mm, film thickness: 0.25μm
Temperature rising program: From 50 ° C to 280 ° C at 10 ° C / min
Carrier gas: Nitrogen gas
Detector: FID

<Examples 6 to 11>
Using the same apparatus as in Example 5, the catalyst shown in Table 1, phenols (0.1 mol), aliphatic carboxylic acid (0.2 mol), and 300 ml of toluene as a solvent were charged, and water by-produced under reflux was added. The mixture was stirred for 3 hours with azeotropic dehydration. After completion of the reaction, the product was analyzed by gas chromatography to determine the yield of the corresponding aromatic ester (based on phenols). The results are shown in Table 1.

<Comparative Example 1>
Using the same apparatus as in Example 5, 98% sulfuric acid (10 mmol), phenol (0.1 mol), acrylic acid (0.2 mol) as a catalyst, and 300 ml of toluene as a solvent were charged, and water produced as a by-product under reflux was combined. The mixture was stirred for 3 hours while boiling dehydration. After completion of the reaction, the product was analyzed by gas chromatography, and the yield of acrylic acid phenyl ester relative to phenol was determined. The results are shown in Table 1. Further, the reaction solution was distilled to purify the aromatic ester.

<Comparative example 2>
The same operation as in Comparative Example 1 was performed except that phosphotungstic acid hexahydrate was used instead of 98% sulfuric acid. The results are shown in Table 1.

<Comparative Example 3>
The same operation as in Comparative Example 1 was conducted except that phosphotungstic acid hexahydrate and methacrylic acid instead of acrylic acid were used instead of 98% sulfuric acid. The results are shown in Table 1.

<Comparative example 4>
The same operation as in Comparative Example 1 was conducted except that phosphotungstic acid hexahydrate and p-phenylphenol (p-PP) were used instead of 98% sulfuric acid instead of phenol. The results are shown in Table 1.

<Comparative Example 5>
The same operation as in Comparative Example 1 was conducted except that trifluoromethanesulfonic acid (TfOH) was used instead of 98% sulfuric acid. The results are shown in Table 1.

<Comparative Example 6>
The same operation as in Comparative Example 1 was conducted except that 11.52 g of silica gel (SiO ₂ ) was used instead of 98% sulfuric acid. The results are shown in Table 1.

<Example 12>
From the gas chromatographic analysis of the product of Example 8, the ratio of impurities to product was calculated. The results are shown in Table 2.

<Comparative Example 7>
The reaction was carried out in the same manner as in Example 8 except that 2 mmol of phosphotungstic acid hexahydrate was used instead of catalyst A2, and the reaction time was changed from 3 hours to 5 hours. The product was analyzed by gas chromatography to determine the yield of the corresponding aromatic ester (based on p-PP) and the ratio of impurities to product. The results are shown in Table 2.

<Comparative Example 8>
The reaction was conducted in the same manner as in Example 8 except that 2 mmol of TfOH was used instead of the catalyst A2, and the reaction time was changed from 3 hours to 6 hours. The product was analyzed by gas chromatography to determine the yield of the corresponding aromatic ester (based on p-PP) and the ratio of impurities to product. The results are shown in Table 2.

According to the production method of the present invention, an industrially useful aromatic ester compound can be provided from a phenol and a carboxylic acid in a high yield with a small amount of catalyst and a short reaction time. Furthermore, since there are few wastes at the time of manufacture, the manufacturing method of the aromatic ester compound which considered the environmental problem is provided.

Claims (3)

Upon preparing aromatic esters from phenols and unsaturated aliphatic carboxylic acids, process for producing an aromatic ester compound, which comprises using the following esterification catalysts.
○ Esterification catalyst: heteropolyacid carrier or heteropolyacid salt carrier,
At least one oxide selected from the group consisting of Mo, W, Nb and V and at least one oxide selected from the group consisting of P, Si, As, Ge, B, Ti, Co and Ce. A heteropolyacid carrier or heteropolyacid salt carrier obtained by condensation with an oxyacid. The production of an aromatic ester compound according to claim 1, wherein the phenol and unsaturated aliphatic carboxylic acid are used in a molar ratio of the reactive groups of 1:10 to 10: 1 (phenolic hydroxyl group: carboxyl group). Method. The amount of the heteropolyacid and / or heteropolyacid salt in the support is 0.01 to 30 mol% of the heteropolyacid and / or heteropolyacid salt with respect to the smaller number of moles of the phenol or carboxylic acid substrate. The manufacturing method of the aromatic ester compound of Claim 1 or Claim 2 used in the ratio of these.