JP4543173B2 - Catalyst for alkylation reaction and method for producing alkyl-substituted aromatic compound - Google Patents

Description

  The present invention relates to an alkylation reaction catalyst and a method for producing an alkyl-substituted aromatic compound using the catalyst.

  Alkyl-substituted aromatic is a general term for compounds having the structural formula shown in Chemical Formula 1 below, and is one of useful chemical materials.

However, R < ¹ > -R < ⁵ > in a formula shows hydrogen, an alkyl group, an alkoxy group, a phenyl group, and R < ⁶ > -R < ⁸ > shows hydrogen, an alkyl group, and a phenyl group.

  The alkyl-substituted aromatic having the above structural formula is conventionally produced by a method of alkylating by reacting an aromatic compound and an alcohol as shown in the following chemical formula 2, for example.

However, R < ¹ > -R < ⁸ > in a formula is the same as the structural formula shown to the said Chemical formula 1.

  Since the alkylation reaction generally has a slow reaction rate under non-catalytic conditions, an alkylation reaction catalyst is required. Bronsted acids such as sulfuric acid are known to have high catalytic activity, and some methods for producing alkyl-substituted aromatics using an acidic liquid such as sulfuric acid as a catalyst have been industrially implemented.

  However, the sulfuric acid catalyst does not necessarily have sufficient activity, and it is difficult to separate the acidic liquid from the product mixture solution after the reaction. For this reason, a basic aqueous solution is added to extract the organic matter after neutralization, a waste salt aqueous solution is formed, and a new acidic liquid or basic aqueous solution is required each time the reaction is repeated. These lead to high costs for the treatment of waste salt aqueous solutions and the purchase and production of new acidic liquids and base aqueous solutions. In addition, wasteful use of resources and energy, and even when the waste salt aqueous solution is treated, give a load to the environment, which causes a large loss to the environment. Therefore, there is a demand for a catalyst that has higher activity, can be easily separated from the reaction system, and can be used repeatedly.

  For these reasons, it is known to use solid catalysts such as sulfuric acid-treated montmorillonite catalysts, zeolite beta catalysts, and niobium oxide catalysts for the production of alkyl-substituted aromatics. Non-Patent Document 1 discloses that the sulfuric acid-treated montmorillonite catalyst is used for producing an alkyl-substituted aromatic by a reaction between t-butyl alcohol and resorcinol. Non-Patent Document 2 discloses that the niobium oxide catalyst is used for the production of an alkyl-substituted aromatic by the benzylation reaction of anisole.

However, there is a demand for development of a solid catalyst that is not sufficiently active in each of the solid catalysts, has a higher activity, can be easily separated from the product mixed solution, and can be used repeatedly.
Applied Catalysis, A: General, Vol. 213, 273 (2001) Catalysis Today, Vol. 28, 17 (1996)

As a result of various studies on a catalyst capable of obtaining an alkyl-substituted aromatic compound in a high yield by alkylating an aromatic compound with an alcohol, the present inventors dissolved ammonium tungstate and niobium oxalate in water and evaporated the water. Compared with W-Nb composite oxide (solid catalyst) having a composition of Nb _a W _1-a O _{5 / 2a + 3 (1-a)} (0.15 <a <0.55) obtained by removing and firing And presented at the 94th Catalysis Conference (Preliminary Publication Date: September 27, 2004) under the title of “Anisole Benzylation with Nb ₂ O 5 —WO ₃ Catalyst” .

As a result of further research on the basis of the W-Nb composite oxide in order to obtain a catalyst exhibiting higher activity, the present inventors have added phosphorus to the W-Nb composite oxide and have the general formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _y , where x and y are 0.05 ≦ x ≦ 0.7 and 0.08 ≦ y ≦ 0.29, In the reaction system in which the solid catalyst containing the composite oxide represented by formula (1) produces an alkyl-substituted aromatic, the W-Nb composite oxide is originally converted into sulfuric acid-treated montmorillonite, zeolite beta and zirconia-supported tungsten oxide. As a result, the present invention was completed.

According to the present invention, the general formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _y , where x and y are 0.05 ≦ x ≦ 0.7, 0.08 There is provided a catalyst for alkylation reaction comprising a composite oxide represented by ≦ y ≦ 0.29.

According to the present invention, the general formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _y , where x and y are 0.05 ≦ x ≦ 0.7, 0. An alkyl-substituted fragrance characterized by reacting an aromatic compound with an alcohol in the presence of an alkylation reaction catalyst containing a composite oxide represented by the following formula: 08 ≦ y ≦ 0.29 A method for producing a Group compound is provided.

  According to the present invention, there is provided an alkylation reaction catalyst which has high activity in a reaction system for producing an alkyl-substituted aromatic, can be separated from a product mixture solution after the reaction by a method such as filtration, and can be used repeatedly. Can be provided.

  Further, according to the present invention, an aromatic compound and an alcohol can be sufficiently reacted in the presence of the alkylation reaction catalyst, and an alkyl-substituted aromatic can be produced with a high conversion rate and a high yield. A method for producing a possible alkyl-substituted aromatic can be provided.

  Hereinafter, the alkylation reaction catalyst and the method for producing an alkyl-substituted aromatic compound according to the present invention will be described in detail.

The alkylation reaction catalyst according to this embodiment includes a composite oxide represented by the general formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _y . However, x and y in a formula show 0.05 <= x <= 0.7 and 0.08 <= y <= 0.29.

  In the composite oxide of the above general formula, it becomes difficult to obtain a catalyst exhibiting high activity during the alkylation reaction even if the value of x is less than 0.05 or more than 0.7. A more preferable value of x is 0.08 ≦ x ≦ 0.4.

  In the composite oxide of the above general formula, it becomes difficult to obtain a catalyst exhibiting high activity during the alkylation reaction even if the value of y is less than 0.08 or more than 0.29. A more preferable value of y is 0.1 ≦ y ≦ 0.2.

  The catalyst according to the embodiment is in a solid state such as powder, granule, granule, or pellet.

  The composite oxide represented by the general formula contained in such an alkylation reaction catalyst is produced, for example, by the following method.

First, niobium oxide and oxalic acid are added to water, for example, heated to 40 to 90 ° C. and dissolved to prepare a niobium oxalate aqueous solution. Moreover, ammonium tungstate hydrate is added to water, for example, heated to 60 to 90 ° C. and dissolved to prepare an aqueous solution of ammonium tungstate. Subsequently, the niobium oxalate aqueous solution and the ammonium tungstate aqueous solution are mixed in such a ratio that x of the composite oxide of the general formula becomes the above value. A phosphoric acid aqueous solution having a concentration at which y of the composite oxide of the general formula is the above value is added to the mixed solution. Subsequently, this mixed liquid is heated to, for example, 80 to 110 ° C. while stirring to evaporate water to obtain a powder. Next, the powder is further dried at 100 ° C. in the air, and then fired at about 500 ° C. in the air to obtain the general formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _Y (wherein x and y in the formula represent 0.05 ≦ x ≦ 0.7 and 0.08 ≦ y ≦ 0.29).

  Next, a method for producing an alkyl-substituted aromatic compound using the aforementioned alkylation reaction catalyst will be described.

  First, the aromatic compound and the alcohol are both stored in a liquid state in a reaction vessel. A solid-state alkylation reaction catalyst containing the composite oxide represented by the above general formula is placed in the reaction vessel and stirred at a target reaction temperature to react the aromatic compound with the alcohol, and the aromatic compound. Is alkylated to produce an alkyl-substituted aromatic compound.

  Examples of the aromatic compound include benzene, toluene, xylene, ethylbenzene, anisole and the like.

  Examples of the alcohol include methyl alcohol, ethyl alcohol, propylene alcohol, benzyl alcohol and the like.

  The amount of the alkylation catalyst is preferably about 0.1 to 5% by weight, although it depends on the type of aromatic compound and alcohol used in the reaction.

  The catalyst for the alkylation reaction is heated at 150 to 500 ° C. under a flow of an inert gas such as nitrogen gas before being added to a reaction vessel containing a liquid aromatic compound and alcohol, and is dried. It is preferable to maintain. If the temperature at the time of drying is less than 150 ° C., it becomes difficult to sufficiently evaporate the water adhering to the catalyst. On the other hand, if the temperature during drying exceeds 500 ° C., the properties of the catalyst may change.

  The alkylation reaction catalyst is separated from the product mixture solution after the reaction by a separation method such as filtration or centrifugation, and is allowed to be repeatedly used in the reaction. The alkylation reaction catalyst of the embodiment can be easily separated from the product mixed solution without eluting the active component, and can be used repeatedly and can maintain its high activity state.

  Hereinafter, embodiments of the present invention will be described in detail.

(Comparative Example 1)
1.271 g of niobium oxide (COMPANHIA BRASILEIRA METALURGIA MINERACA brand name: NIOBIUMU OXIDE HYDRATE-HY340) and 4.765 g of oxalic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were placed in 100 mL of water and dissolved by heating to about 80 ° C. Further, 1.69 g of ammonium tungstate pentahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in 100 mL of water and dissolved by heating to about 80 ° C. These solutions were mixed and heated with stirring on a hot plate to evaporate water to obtain powder. These powders are dried in air at 100 ° C. for 1 hour and then calcined in air at 500 ° C. for 3 hours to obtain a W—Nb composite oxide having a composition of (Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 A solid catalyst consisting of

(Examples 1-6 and Comparative Examples 2-5)
1.271 g of niobium oxide (COMPANHIA BRASILEIRA METALURGIA MINERACA brand name: NIOBIUMU OXIDE HYDRATE-HY340) and 4.765 g of oxalic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were placed in 100 mL of water and dissolved by heating to about 80 ° C. Further, 1.69 g of ammonium tungstate pentahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in 100 mL of water and dissolved by heating to about 80 ° C. These solutions were mixed, 7.5 mL of phosphoric acid aqueous solutions having different concentrations (made by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was heated on a hot plate while stirring to evaporate water to obtain powder. These powders were dried in air at 100 ° C. for 1 hour and then calcined in air at 500 ° C. for 3 hours to obtain the formula I: [(Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 (P ₂ O ₅ ) _y ] (y = 0.036, 0.050, 0.052, 0.064, 0.086, 0.103, 0.122, 0.137, 0.171, 0.282) 10 A solid catalyst composed of a seed W-Nb-P composite oxide was obtained. The phosphorus content (y) was identified by ICP (inductively coupled plasma) emission analysis using a CIROS-120 analyzer manufactured by Rigaku Corporation after dissolving a part of each composite oxide in hydrofluoric acid.

(Comparative Example 6)
0.25 g of montmorillonite (trade name: Montmorillonite K-10, manufactured by Wako Pure Chemical Industries, Ltd.) was stirred for 2 hours at 80 ° C. in 50 mL of 30 wt% sulfuric acid aqueous solution, and then filtered. The obtained solid was washed twice with 200 g of water, dried in air at 100 ° C. for 10 hours, and further calcined in air at 500 ° C. for 3 hours to obtain a solid catalyst composed of sulfuric acid-treated montmorillonite.

  0.1 g of the obtained solid catalysts of Examples 1 to 6 and Comparative Examples 1 to 6 were heated at 400 ° C. for 1 hour under the flow of nitrogen gas (manufactured by Iwatani Corp.), and anisole 10 was kept dry. The flask was transferred to a flask containing 0.0 g and 0.675 g of benzyl alcohol, and the mixture was stirred at 60 ° C. for 3 hours to be reacted. The composition of the product mixed solution after the reaction was analyzed by gas chromatography. In the analysis, 1.0 g of n-tridecane (manufactured by Kanto Chemical Co., Inc.) as an internal standard substance was added to the product mixture solution after the reaction, and 0.001 mL thereof was equipped with a capillary column (trade name: MDN-12 manufactured by SUPELCO). Were injected into a gas chromatograph (trade name: GC-2010, manufactured by Shimadzu Corporation), and each component was quantified by an internal standard method.

  From the quantitative results, the conversion rate of benzyl alcohol in each catalyst was determined. Moreover, the yield of the target product, benzylanisole (total of o-benzylanisole, m-benzylanisole, and p-benzylanisole) was determined from the following formula.

Yield (%) = [Benzylanisole yield (mol) / Benzyl alcohol charge (mol)] × 100
These results are shown in Table 1 below. The results in Table 1 below are shown in FIG. 1 as the relationship between the conversion rate of benzyl alcohol and the yield of benzylanisole with respect to y in the formula I.

  As is apparent from Table 1 and FIG. 1, the solid catalyst composed of the W—Nb—P composite oxide to which phosphorus of Comparative Examples 2 to 5 and Examples 1 to 6 was added was not added with the phosphorus of Comparative Example 1. It can be seen that the activity is higher in the alkylation reaction than the solid catalyst made of -Nb composite oxide. In particular, in the solid catalysts composed of W—Nb—P composite oxide in which y in Formula I in Examples 1 to 6 is 0.08 ≦ y ≦ 0.29, y in Comparative Examples 2 to 5 falls within the above range. It can be seen that not only the solid catalyst composed of the W—Nb—P composite oxide that deviates but also the solid catalyst composed of the sulfuric acid-treated montmorillonite of Comparative Example 6 has a high conversion rate and yield and exhibits extremely high activity.

(Comparative Example 9)
Zeolite beta (trade name: VALFOR CP811BL-25 manufactured by PQ) was used as the solid catalyst.

(Comparative Example 10)
1.69 g of ammonium tungstate pentahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in 100 mL of water and dissolved by heating to about 80 ° C. 7.5 mL of a phosphoric acid aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having a concentration of 0.25 mol / L was added to this solution, and the mixture was heated on a hot plate with stirring to evaporate water to obtain a powder. The powder is dried in air at 100 ° C. for 1 hour, and then calcined in air at 500 ° C. for 3 hours, _whereby a WP composite oxide having a composition of (WO ₃ ) ₁ (P ₂ O ₅ ) _0.122 A solid catalyst consisting of

(Comparative Example 11)
1.271 g of niobium oxide (COMPANHIA BRASILEIRA METALURGIA MINERACA brand name: NIOBIUMU OXIDE HYDRATE-HY340) and 4.765 g of oxalic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were placed in 100 mL of water and dissolved by heating to about 80 ° C. 7.5 mL of a phosphoric acid aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) having a concentration of 0.25 mol / L was added to this solution, and the mixture was heated on a hot plate with stirring to evaporate water to obtain a powder. This powder is dried in air at 100 ° C. for 1 hour, and then calcined in air at 500 ° C. for 3 hours, _whereby an Nb—P composite having a composition of (Nb ₂ O ₅ ) ₁ (P ₂ O ₅ ) _0.122 A solid catalyst comprising an oxide was obtained.

Example 7 (same composition as Example 3 described above: [(Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 (P ₂ O ₅ ) _0.122 ]), Comparative Example 7 (Sulfuric acid-treated montmorillonite of Comparative Example 6 described above) , Comparative Example 8 (same composition as Comparative Example 1 described above: [(Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 ]), 0.1 g of the solid catalysts of Comparative Examples 9 to 11 were replaced with nitrogen gas (manufactured by Iwatani Corporation). The mixture was heated at 400 ° C. for 1 hour under the flow of No. 1 and transferred to a flask containing 10.0 g of anisole and 0.675 g of benzyl alcohol while maintaining the dry state, and the mixture was mixed at 50 ° C., 60 ° C., 70 ° C. and The mixture was stirred at 80 ° C. for 3 hours to be reacted. The composition of the product mixed solution after the reaction was analyzed by the gas chromatography described above, and the conversion rate of benzyl alcohol and the yield of benzylanisole at each reaction temperature were determined. The results are shown in Table 2 below. Moreover, the relationship between the reaction temperature by the solid catalyst of Example 7 and Comparative Example 7 and the yield of benzylanisole is shown in FIG.

  As is clear from Table 2, the solid catalyst composed of sulfuric acid-treated montmorillonite of Comparative Example 7 was a solid catalyst composed of zeolite beta of Comparative Example 8 at a reaction temperature of 80 ° C., and a solid catalyst composed of Nb—W composite oxide of Comparative Example 9. It can be seen that the activity is higher than that of the catalyst, the solid catalyst composed of the WP composite oxide of Comparative Example 10 and the solid catalyst composed of the Nb-P composite oxide of Comparative Example 11.

On the other hand, as is clear from Table 2 and FIG. 2, in the solid catalyst composed of the composite oxide of (Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 (P ₂ O ₅ ) _0.122 of Example 7, It can be seen that even at the reaction temperature, the activity is higher than that of the solid catalyst comprising the sulfuric acid-treated montmorillonite of Comparative Example 7 having high activity. In particular, it can be seen that the solid catalyst of Example 7 can convert most of benzyl alcohol to benzylanisole at a reaction temperature of 80 ° C.

(Example 8)
(Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 (P ₂ O ₅ ) 0.2 g of solid catalyst composed of _0.122 is heated at 400 ° C. for 1 hour under the flow of nitrogen gas (Iwatani Corp.). Then, while keeping the dry state, the mixture was transferred to a flask containing 20.0 g of anisole and 1.350 g of benzyl alcohol, and the mixture was stirred at 60 ° C. and 80 ° C. for 3 hours to be reacted. The composition of the product mixed solution after the reaction was analyzed by the gas chromatography described above, and the conversion rate of benzyl alcohol and the yield of benzylanisole at each reaction temperature were determined.

  Next, the catalyst was filtered off from the product mixed solution after the reaction at 60 ° C. and 80 ° C. using a filter paper (trade name: No. 131, manufactured by Advantec) under normal pressure, and without performing treatment such as calcination and washing, The reaction (an alkylation reaction) of anisole and benzyl alcohol was repeated (twice).

  That is, filtration was performed after the reaction, and 0.0906 g of the catalyst remaining on the filter paper, 9.0 g of anisole, and 0.602 g of benzyl alcohol were mixed, and these mixed solutions were mixed at a temperature of 60 ° C. and 80 ° C. The reaction was stirred for an hour. Filtration was performed again, and 0.0449 g of the catalyst remaining on the filter paper, 4.5 g of anisole, and 0.305 g of benzyl alcohol were mixed, and these mixed solutions were stirred at 60 ° C. and 80 ° C. for 3 hours. Reacted. The composition of the product mixed solution after each reaction was similarly analyzed by gas chromatography to determine the conversion rate of benzyl alcohol and the yield of benzylanisole at each reaction temperature.

  These results are shown in Table 3 below.

As is apparent from Table 3, the solid catalyst _comprising the composite oxide of (Nb ₂ O ₅ ) _0.37 (WO ₃ ) _0.63 (P ₂ O ₅ ) _0.122 has a slight decrease in activity when used repeatedly at a reaction temperature of 60 ° C. However, it can be seen that a sufficiently high activity can be maintained even at the third time.

  It can also be seen that the solid catalyst exhibits a yield of benzylanisole close to 100% even at the third time at a relatively high temperature of 80 ° C.

  On the other hand, as a result of analyzing the filtrate filtered after the first reaction at 60 ° C., benzyl alcohol corresponding to about 68% before the reaction remained. The filtrate was subjected to reaction conditions of stirring at 60 ° C. for 3 hours to examine whether benzylanisole was formed. As a result, the formation of benzylanisole was not confirmed. This fact and the results in Table 3 show that the solid catalyst does not elute the active component by filtration and can be easily separated from the product solution after the reaction.

The figure which shows the relationship between the conversion rate of benzyl alcohol with respect to y of the formula I which is a solid catalyst, and the yield of benzylanisole. The figure which shows the relationship between the reaction temperature by the solid catalyst of Example 7 and Comparative Example 7, and the yield of benzylanisole.

Claims (4)

General formula (Nb ₂ O ₅ ) _x (WO ₃ ) _1-x (P ₂ O ₅ ) _y , where x and y are 0.05 ≦ x ≦ 0.7, 0.08 ≦ y ≦ 0. 29. The catalyst for alkylation reaction characterized by including the complex oxide represented by (29).   A process for producing an alkyl-substituted aromatic compound, wherein an alkylation is carried out by reacting an aromatic compound with an alcohol in the presence of the alkylation reaction catalyst according to claim 1.   The method for producing an alkyl-substituted aromatic compound according to claim 2, wherein the alkylation reaction catalyst is separated from the product mixture solution after the reaction and is repeatedly used in the reaction.   The method for producing an alkyl-substituted aromatic compound according to claim 2 or 3, wherein the aromatic compound is anisole, and the alcohol is benzyl alcohol.

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