JP2006218358A - Esterification catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method which overcomes disadvantages of conventional production methods of aromatic ester compounds and by which corresponding aromatic ester compounds can be efficiently produced in high yields from phenols and carboxylic acids. <P>SOLUTION: An esterification catalyst is disclosed which comprises a super acid and/or a heteropolyacid and/or a heteropolyacid salt, and boronic acid and/or boronic acid ester and/or boron oxide. The method for producing ester compounds using the esterification catalyst is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a catalyst used in an esterification reaction and a method for producing an aromatic ester compound using the catalyst, and a high-yield fragrance by esterification reaction of a phenol and a carboxylic acid using the catalyst. The present invention relates to a method for producing a group ester compound.

  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 of phenols and carboxylic acids is difficult to obtain in high yield due to the high acidity and equilibrium problems of 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, a method for obtaining an aromatic ester compound using a tin compound (see, for example, Patent Document 5), a lead compound (see, for example, Patent Document 6), metallic tin and / or metallic lead (for example, see Patent Document 7) as a catalyst is also disclosed. However, in both cases, the reaction rate is low, and separation and purification such as catalyst removal is difficult.

  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 been proposed (see, for example, Patent Document 8). ) 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 using a heteropolyacid (for example, see Patent Document 10) or an acid salt of the heteropolyacid (for example, see Patent Document 11) as a catalyst has been proposed. However, all these alcohols are aliphatic alcohols, and no mention or suggestion is made regarding the reaction between phenols and carboxylic acids.

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.
Aromatic ester compounds have properties such as 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.

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 2002-121170 A (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 can solve the above-mentioned problems by using an esterification catalyst comprising a super strong acid and / or a heteropoly acid and / or a heteropoly acid salt and a boronic acid and / or a boronic acid ester and / or boron oxide. The headline and the present invention have been completed. 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, for example, an aromatic ester compound can be obtained with good yield from a phenol and a carboxylic acid 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 ester compound of the present invention is such that the first component is a super strong acid and / or heteropoly acid and / or heteropoly acid salt, and the second component is boronic acid and / or boronic ester and / or boron oxide. It consists of The catalyst may be a solid acid in which a super strong acid, heteropoly acid, or heteropoly acid salt as the first component is supported on an inorganic carrier. Details will be described below.

○ The superacid which may be used first component of the esterification catalyst in the superacid present invention, stronger than 100% sulfuric acid, i.e., Hammett acidity function when expressed in (hereinafter, H ₀ and abbreviated), H ₀ = An acid showing a value smaller than -11.93.
Super strong acids that can be used in the present invention include solid super strong acids and liquid super strong acids supported on a carrier.
As the solid super strong acid, for example, a support made of hydroxide or oxide such as silicon, aluminum, titanium, zirconium, tungsten, molybdenum, tin, or iron, sulfate radical, antimony pentafluoride, tantalum pentafluoride, Or, boron trifluoride adhering or supporting; zirconium oxide, stannic oxide, titania, ferric oxide or the like supporting tungsten oxide; perfluoroalkylsulfonic acid resin or perfluoroalkylsulfonic acid resin And those on which silica is supported.
Examples of the liquid super strong acid include halogenated sulfonic acids such as chlorosulfonic acid (H ₀ = -13.80) and fluorinated sulfonic acid (H ₀ = -15.07); trifluoromethane sulfonic acid (H ₀ =- 14.5), perfluoro sulfonic acid (H ₀ = -14.0), perfluorobutane sulfonic acid (H ₀ = -13.2), and perfluorohexane sulfonic acid (H ₀ = -12.3) And halogenated alkyl sulfonic acids.

Heteropolyacid or heteropolyacid salt The heteropolyacid that can be used as the first component of the esterification catalyst in 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 atomic ratio of the 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, phosphomolybdo-tungstovanadic 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.

Inorganic carrier In the present invention, the inorganic carrier on which the first component of the esterification catalyst is supported can be exemplified by powder, granule, or particulate solid, preferably granular or particulate. 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, BaO, and the like, or a mixture thereof. Examples of the mixture include SiO ₂ —MgO, SiO ₂ —Al ₂ O ₃ , SiO ₂ —TiO _{2 and the} like. Of these, those containing as a main component at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ are preferred.
As a method for supporting the first component of the catalyst on the inorganic support, a conventional method may be used (for example, a method of supporting a heteropolyacid and / or a heteropolyacid salt: Chem. Lett., 2002, p. 1104, Catalyst, 1997, 39, 4, p.292, etc.).

  The amount of the first component of the catalyst used in the present invention supported on the inorganic carrier is preferably 3 to 75% by weight, more preferably 5 to 50% by weight. If the supported amount is less than 3% by weight, sufficient acid catalytic ability cannot be exhibited, and if it is more than 75% by weight, it is economically disadvantageous.

Boronic acid Boronic acid that can be used as the second component of the esterification catalyst in the present invention is a compound having one or more B-OH bonds in the molecule. For example, boric acid, phenyl boric acid, 4-chlorophenyl boric acid, 4-fluorophenyl boric acid, hexyl boric acid, 2-methoxyphenyl boric acid, 1-naphthyl boric acid, o-tolyl boric acid, m-tolyl boric acid, p-tolyl boric acid 3,5-bis (trifluoromethyl) phenyl boric acid, diphenyl boric acid and the like.

Boronic acid ester The boronic acid ester that can be used as the second component of the esterification catalyst in the present invention is an ester compound of the above boronic acid and alcohol. Examples thereof include triamyl borate, tributyl borate, triethyl borate, trimethyl borate, triisopropyl borate and the like.

The super strong acid or heteropolyacid and / or salt thereof, which is the first component of the esterification catalyst, can be used alone or in combination of a plurality of types, but considering the activity as the esterification catalyst, The first component is preferably a super strong acid and / or heteropoly acid and / or a heteropoly acid supported on an inorganic carrier.
As the super strong acid, a perfluoroalkyl sulfonic acid resin supported on silica, a halogenated sulfonic acid, a halogenated alkyl sulfonic acid and the like are particularly preferable.
As the heteropolyacid, the metal element constituting the oxide is preferably molybdenum and / or tungsten, and the oxyacid is preferably phosphorus or silicon. That is, phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, and / or silicomolybdic acid are suitable.

  Further, the boronic acid or boronic acid ester which is the second component of the esterification catalyst can be used alone or in combination, but considering the activity as the esterification catalyst, the second component As boronic acid or boronic acid ester, boric acid or a lower ester compound thereof is more preferable.

○ 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.

○ Carboxylic acid Examples of the carboxylic acid in the present invention include aliphatic carboxylic acids and aromatic carboxylic acids. Examples of aliphatic carboxylic acids include acetic acid, propionic acid, acrylic acid, methacrylic acid, crotonic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, oleic acid and stearic acid And monocarboxylic acids such as maleic acid, fumaric acid, adipic acid, sebacic acid and azelaic acid.
Examples of the aromatic carboxylic acid include benzoic acid, toluic acid, ethyl benzoic acid, and methoxybenzoic acid.
In the present invention, an aliphatic carboxylic acid is preferably used, more preferably a monocarboxylic acid. In view of industrial utility, unsaturated carboxylic acids having polymerization activity such as acrylic acid, methacrylic acid and crotonic acid are used. Acrylic acid or methacrylic acid is more preferable. Acrylic acid and methacrylic acid may be collectively 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 excessively used phenols and aliphatic carboxylic acids can be reused after being separated from the aromatic ester compound produced after the reaction.

  In the present invention, the first component (super strong acid and / or heteropolyacid and / or heteropolyacid salt) used as a catalyst, and the second component (boronic acid and / or boronic acid ester and / or boron oxide) The molar ratio is preferably in the range of 5: 1 to 1: 5 (first component: second component), more preferably 3: 1 to 1: 3.

  Moreover, the first component and the second component of the catalyst may be mixed in advance or may be added separately to the reaction system.

  The amount of the super strong acid and / or heteropoly acid and / or heteropoly acid salt, which is the first component of the catalyst 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 phenols or carboxylic acids used in the reaction, the amount of super strong acid and / or heteropolyacid and / or heteropolyacid salt is preferably 0.01 to 30 mol% with respect to a smaller number of moles of substrate. Preferably it is 0.05-20 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 the gas phase or liquid phase reaction can be selected depending on the type of the 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 remove water more efficiently. 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. Moreover, superposition | polymerization can also be suppressed by blowing in air.

  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 washing with water, 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.

<Synthesis Example 1>
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 / l, and 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 A).

<Example 1>
A 300 ml three-necked flask equipped with a stirrer, a condenser, a water separator (Dean-Stark trap) and a thermometer was charged with trifluoromethanesulfonic acid (0.5 mmol, hydrogen ion content 0.5 mmol), boric acid ( 0.5 mmol), phenol (0.1 mol), acrylic acid (0.2 mol), 0.034 g of methoxyhydroquinone and 150 ml of toluene were charged, and dry air was blown in. The reaction mixture was heated and stirred for 10 hours while azeotropically dehydrating the by-product water under toluene reflux. 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

<Example 2>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that methacrylic acid was used instead of acrylic acid. The results are shown in Table 1.

<Example 3>
The same procedure as in Example 1 was performed except that o-phenylphenol was used instead of phenol, and the yield of the aromatic ester was determined. The results are shown in Table 1.

<Example 4>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that 0.5 mmol of 3,5-bis (trifluoromethyl) phenylboric acid was used instead of boric acid. The results are shown in Table 1.

<Example 5>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that 0.5 mmol of triethyl borate was used instead of boric acid. The results are shown in Table 1.

<Example 6>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that 0.25 mmol of boron oxide was used instead of boric acid. The results are shown in Table 1.

<Example 7>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that 0.5 mmol of phosphotungstic acid hexahydrate was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Example 8>
In the same apparatus as in Example 1, silica-supported perfluoroalkylsulfonic acid resin (manufactured by N.E. Catcat Co., Ltd., 0.5 mmol, hydrogen ion content 0.5 mmol), phenylboric acid (0.5 mmol), p -Phenylphenol (0.1 mol), methacrylic acid (0.2 mol), 0.034 g of methoxyhydroquinone and 150 ml of toluene were charged and dry air was blown. The reaction mixture was heated and stirred for 10 hours while azeotropically dehydrating the by-product water under toluene reflux. After completion of the reaction, the product was analyzed by gas chromatography to determine the yield. The results are shown in Table 1.

<Example 9>
In the same apparatus as in Example 1, silica-supported perfluoroalkylsulfonic acid resin (manufactured by N.E. Catcat Co., Ltd., 0.5 mmol, hydrogen ion content 0.5 mmol), boric acid (0.5 mmol), p -Phenylphenol (0.1 mol), acrylic acid (0.2 mol), 0.034 g methoxyhydroquinone and 150 ml toluene were charged and dry air was blown. The reaction mixture was heated and stirred for 10 hours while azeotropically dehydrating the by-product water under toluene reflux. After completion of the reaction, the product was analyzed by gas chromatography to determine the yield. The results are shown in Table 1.

<Example 10>
The yield of the aromatic ester was determined in the same manner as in Example 1 except that catalyst A (hydrogen ion content: 0.5 mmol) was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Comparative Example 1>
Using the same apparatus as in Example 1, trifluoromethanesulfonic acid (0.5 mmol, hydrogen ion content 0.5 mmol), phenol (0.1 mol), acrylic acid (0.2 mol), 0.034 g Methoxyhydroquinone and 150 ml of toluene were charged, and the mixture was heated and stirred for 10 hours while azeotropically dehydrating water produced as a by-product under reflux. 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.

<Comparative example 2>
The same operation as in Comparative Example 1 was performed except that o-phenylphenol was used instead of phenol. The results are shown in Table 1.

<Comparative Example 3>
The same operation as in Comparative Example 1 was performed except that 0.5 mmol of boric acid was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Comparative example 4>
The same operation as in Comparative Example 1 was performed except that 0.25 mmol of boron oxide was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Comparative Example 5>
The same operation as in Comparative Example 1 was performed except that 0.5 g of 98% sulfuric acid (hydrogen ion content was 5 mmol) was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Comparative Example 6>
The same operation as in Comparative Example 1 was conducted except that 0.5 g of 98% sulfuric acid (hydrogen ion content was 5 mmol) and 5 mmol of boric acid were used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

<Comparative Example 7>
The same operation as in Comparative Example 1 was performed except that 1.5 g of phosphomolybdic acid hexahydrate (hydrogen ion content was 0.5 mmol) was used instead of trifluoromethanesulfonic acid. The results are shown in Table 1.

○ The abbreviations in Table 1 are described below.
TfOH: trifluoromethanesulfonic acid TFM-PBA: 3,5-bis (trifluoromethyl) phenylboric acid WPA: phosphotungstic acid hexahydrate SAC-13: silica-supported perfluoroalkylsulfonic acid resin (N ChemCat) (Made by Co., Ltd.)
Et-BA: Triethyl borate PBA: Phenyl boric acid o-PP: o-phenylphenol p-PP: p-phenylphenol

  By using the catalyst 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.

Claims (6)

  An esterification catalyst comprising a super strong acid and / or a heteropolyacid and / or a heteropolyacid salt and a boronic acid and / or a boronic acid ester and / or boron oxide.   The heteropolyacid or heteropolyacid salt is selected from the group consisting of at least one oxide selected from the group consisting of Mo, W, Nb and V, and the group consisting of P, Si, As, Ge, B, Ti, Co and Ce 2. The esterification catalyst according to claim 1, wherein the esterification catalyst is a heteropolyacid or heteropolyacid salt obtained from at least one oxyacid.   The esterification catalyst according to claim 1, wherein the super strong acid and / or heteropoly acid and / or heteropoly acid salt is supported on an inorganic carrier.   In the method of manufacturing an aromatic ester from phenols and carboxylic acid, the esterification catalyst as described in any one of Claims 1-3 is used, The manufacturing method of the aromatic ester compound characterized by the above-mentioned.   The method for producing an aromatic ester compound according to claim 4, wherein the carboxylic acid is an aliphatic carboxylic acid.   The method for producing an aromatic ester compound according to claim 5, wherein the aliphatic carboxylic acid is an unsaturated carboxylic acid.