JP2000281610A - Production of ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily and inexpensively obtain an ether useful for cosmetics or the like while avoiding the decrease of activities of a catalyst by using a specific palladium catalyst as the catalyst. SOLUTION: (A) A hydroxy compound, preferably a compound represented by the formula R1-(OA)n-OH (R1 is a 1-40C alkyl, an alkenyl or the like; A is a 2-12C alkylene; n is 0-30), (e.g. glycerol) is reacted with (B) a carbonyl compound, preferably a compound represented by the formula (R2 and R3 are each H, a 1-20C alkyl or an alkenyl), (e.g. methyl ethyl ketone) in the presence of (C) a palladium catalyst supported by a mesoporous aluminosilicate as a catalyst in hydrogen atmosphere to provide the objective ether (e.g. 1,3- dimethylbutyl hexadecyl ether). The pores of the aluminosilicate preferably have 2-10 nm sizes, and the reaction is preferably carried out while removing by-produced water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a simple and inexpensive method for producing ether.

[0002]

2. Description of the Related Art The use of ethers is widespread not only in conventional solvents but also in cosmetics, detergent compositions, lubricants, emulsifiers and the like. Examples of the method for producing such an ether include a synthesis from an alcoholate and an alkyl halide (Williamson synthesis method), a synthesis from an alcohol and an ester compound, a synthesis by a dehydration reaction using an acid between alcohols,
Synthesis by addition of an alcohol to an olefin, synthesis by a hydrogenolysis reaction of a ketal, and the like are common, but both methods have some drawbacks.

On the other hand, there is a method for producing an ether from an alcohol and a carbonyl compound. For example, J. Che
m. Soc., 5598 (1963) and Chem. Commun., 422 (1967) describe a method for synthesizing an ether in an excess alcohol system under a hydrogen atmosphere at normal pressure using an acidic catalyst. However, in this method, the alcohol is in a large excess, and the type of alcohol is only lower alcohols such as methanol, ethanol, and propyl alcohol, and higher alcohols having more than 6 carbon atoms are not described. In recent years, as an example of synthesis of ethers using higher alcohols, a reduction method using triethylsilane using a strong acid as a catalyst has been developed, and various ethers have been synthesized from higher alcohols and various carbonyl compounds (Chemistry).
letters, P.743-746, 1985), strong acids, triethylsilane and the like are sometimes expensive, and are not industrially preferable.

Japanese Patent Application Laid-Open No. 9-67288 discloses a method of condensing a hydroxy compound and a carbonyl compound under a hydrogen atmosphere using a palladium catalyst. This method is very useful because it allows the reaction of higher alcohols, but the reactivity is often determined by the activity of the palladium-supported catalyst, and the development of a highly active palladium-supported catalyst is an important factor in this synthesis method. It is one of the important factors.

[0005] By the way, a palladium-supported catalyst is generally
Although useful as a hydrocarbon combustion catalyst, for example, silica or zeolite is used as a carrier and is commercially available. However, it has also been pointed out that such silica or zeolite cannot avoid a decrease in activity due to sintering when carrying palladium.

[0006]

An object of the present invention is to find a catalyst having a high activity in a process for synthesizing an ether from a hydroxy compound and a carbonyl compound.

[0007]

SUMMARY OF THE INVENTION The present inventors have found that by supporting palladium on a mesoporous aluminosilicate, which is a porous carrier having a substantially uniform pore size larger than zeolite, a decrease in activity can be avoided only. Instead, it was found to be a useful catalyst in the synthesis of the above ether.

The present invention relates to a method for producing ether by reacting a hydroxy compound and a carbonyl compound in a hydrogen atmosphere in the presence of a catalyst, and using a palladium catalyst supported on a mesoporous aluminosilicate as a catalyst. To provide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The hydroxy compound used in the present invention has the general formula (1)

[0010]

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Wherein R ¹ represents a linear or branched alkyl or alkenyl group having 1 to 40 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and A represents 2 to 12 carbon atoms.
Wherein n A's may be the same or different. n shows the number of 0-30. ] The compound represented by this is mentioned.

The compounds represented by the general formula (1) include straight-chain saturated alcohols having 1 to 40 carbon atoms, branched saturated alcohols having 3 to 40 carbon atoms, alkenyl alcohols having 3 to 40 carbon atoms, and mono-ethylene glycols. Ethers, monoethers of diethylene glycol, monoethers of triethylene glycol, monoethers of alkylene glycol, ethylene oxide, propylene oxide or butylene oxide adducts of the above alcohols, and cyclic alcohols having 3 to 12 carbon atoms. .

Among these hydroxy compounds, aliphatic alcohols having 1 to 22, especially 6 to 22 carbon atoms, methyl cellosolve, ethyl cellosolve, isopropyl cellosolve,
Butyl cellosolve, methyl carbitol, ethyl carbitol, isopropyl carbitol, butyl carbitol, ethylene oxide or / and propylene oxide adducts of aliphatic alcohols having 1 to 22 carbon atoms, especially 6 to 22 carbon atoms (average addition mole number 0.1 to 20) ), A cycloalkanol having 5 to 8 carbon atoms is preferable, and an aliphatic alcohol having 6 to 22 carbon atoms, cyclohexanol is more preferable.

Further, a polyhydric alcohol can be used as the hydroxy compound. In this case, a hydroxy ether can also be produced as an ether. Examples of the polyhydric alcohol include linear or branched polyhydric alcohols having 2 to 40 carbon atoms, and specifically, ethylene glycol, propylene glycol, 1,3-propanediol, and 1,2-butanediol , 1,3-butanediol,
Diols such as 1,4-butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol and dodecanediol; glycerins such as glycerin, diglycerin, triglycerin; trimethylolethane And trimethylolalkanes such as trimethylolpropane and trimethylolbutane; erythritol, pentaerythritol and the like, and ethylene oxide and / or propylene oxide adducts thereof. Among these polyhydric alcohols, diols having 2 to 6 carbon atoms and triols such as glycerin, trimethylolethane, and trimethylolpropane are preferable, and glycerin is particularly preferable.

These hydroxy compounds can be used alone or in combination of two or more.

The carbonyl compound used in the present invention has the general formula (2)

[0017]

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[Wherein R ² and R ³ represent a hydrogen atom and a carbon atom of 1
Represents up to 20 linear or branched alkyl or alkenyl groups, and R ² and R ³ may be the same or different. Further, a cyclic structure in which R ² and R ³ together form an alkylene or alkenylene group having 2 to 20 carbon atoms may be used. ] The compound represented by this is mentioned.

The compound represented by the general formula (2) includes a chain ketone having 3 to 41 carbon atoms, a cyclic ketone having 3 to 21 carbon atoms,
Examples thereof include a linear aldehyde having 1 to 21 carbon atoms and a polymer thereof, and a branched aldehyde having 4 to 21 carbon atoms.

Among these carbonyl compounds, a chain ketone having 3 to 12 carbon atoms, an aldehyde having 1 to 12 carbon atoms or a cyclic ketone having 5 to 8 carbon atoms is preferable.
A chain ketone having 3 to 6 carbon atoms such as methyl ethyl ketone and methyl isobutyl ketone (4-methyl-2-pentanone);
Formaldehyde, paraformaldehyde, acetaldehyde, paraaldehyde, butyraldehyde, isobutyraldehyde, octylaldehyde, dodecylaldehyde, etc., and especially aliphatic aldehydes having 3 to 8 carbon atoms such as 3 to 8 and cyclic ketones such as cyclohexanone are particularly preferred. Particularly preferred are acetone, methyl ethyl ketone, and methyl isobutyl ketone (4-methyl-2-pentanone).

In the present invention, alkylglyceryl ethers can be produced by using glycerin as the hydroxy compound and aliphatic aldehyde as the carbonyl compound. These alkyl glyceryl ethers have a high monoalkyl glyceryl ether content, and particularly when an aliphatic aldehyde of 4 to 12 is used, an alkyl glyceryl ether having a carbon chain length useful as a nonionic surfactant can be produced. .

The present invention is characterized in that a palladium catalyst supported on a mesoporous aluminosilicate is used as a catalyst. Here, a mesoporous aluminosilicate has a substantially uniform pore diameter of 2 to 50 nm. This substantially uniform pore diameter can be determined from a powder X-ray diffraction pattern, and is preferably 2 to 10 nm, particularly preferably 2 to 6 nm.

The palladium-supported mesoporous aluminosilicate used in the present invention can be synthesized by synthesizing a mesoporous aluminosilicate having pores larger than zeolite and supporting palladium on the mesoporous aluminosilicate.

The mesoporous aluminosilicate can be synthesized, for example, by the method described in Bull. Chem. Soc. Jpn., 63, 988 (1990), but the ratio of Al to Si is 10% by weight or less. Is preferably synthetically
The pore size of the mesoporous aluminosilicate is 2 to 10
nm, particularly preferably 2 to 6 nm. Examples of the method for supporting palladium include an impregnation method and an ion exchange method, and an ion exchange method is preferable. Palladium salts to be ion-exchanged include PdCl ₂ , Pd (OAc) ₂ , Pd (NH ₄ ) Cl
₂ , [Pd (NH ₃ ) ₄ ] Cl _{2 and the} like, particularly PdCl ₂ , Pd (OA
c) ₂ is preferred.

The amount of palladium supported on the palladium catalyst supported on the mesoporous aluminosilicate is preferably 0.1 to 10% by weight, and the higher the amount supported, the higher the possibility of adverse effects such as sintering during loading.

As a method of ion exchange using PdCl ₂ , Pd (OAc) ₂ or the like, for example, PdCl ₂ is dissolved in aqueous ammonia or Pd (OAc) ₂ is dissolved in a mixture of acetone and water. , A mesoporous aluminosilicate or a salt thereof, and the like.

The amount of palladium-supported mesoporous aluminosilicate used in the present invention is, for example, 5% by weight of palladium in the mesoporous aluminosilicate as a carrier.
If supported, it is preferable to use 0.1 to 10% by weight based on the hydroxy compound used.

The amount of the hydroxy compound and the carbonyl compound to be charged is usually preferably hydroxy compound / carbonyl compound (molar ratio) = 30/1 to 1/30, particularly preferably 20/1 to 1/30.
1/20, more preferably 10/1 to 1/10. If the hydroxy compound has a low molecular weight and can be easily removed, it is preferable to use the hydroxy compound in excess to react all of the carbonyl compound. Further, if the hydroxy compound has a large molecular weight and further solidifies at room temperature or the like,
It is preferable to use an excess of the carbonyl compound and react all the hydroxy compounds that are difficult to remove.

In the present invention, the hydroxy compound and the carbonyl compound are reacted in a hydrogen atmosphere, but the hydrogen pressure is not particularly limited, and may be either pressurization or atmospheric pressure, from 0.1 (atmospheric pressure) to 29.4 MPa, Especially 0.1 (atmospheric pressure) to 19.
6 MPa is preferred.

The reaction temperature in the present invention is not particularly limited, but is preferably from 10 to 200 ° C, particularly preferably from 30 to 180 ° C. The reaction time may be appropriately selected depending on the reaction temperature, hydrogen pressure, amount of catalyst, and the like, but is usually 1 to 24 hours, preferably 1 to 12 hours.

In the reaction of the present invention, a solvent can be used. Examples of the solvent include hydrocarbon solvents such as hexane, heptane, and octane. The amount of the solvent used is preferably 0.5 to 2 times the volume of the reaction solution.

In the present invention, it is preferable to carry out the reaction by removing water produced as a by-product. As a method for removing water, any method can be used as long as water can be distilled out of the reaction system, and examples thereof include a method such as azeotropic dehydration. At this time, a method of distilling off water together with unreacted raw materials is preferable. After distillation,
Preferably, water and unreacted raw materials are separated, and unreacted raw materials are returned to the reaction system. As a method of azeotropic dehydration, for example, using an azeotropic dehydration apparatus, not only a method of continuously performing the reaction and distillation of water, but also, for example, once performing the reaction, performing azeotropic dehydration, and performing the reaction again. A method in which the reaction and the distillation of water are performed in a stepwise manner, such as the method described above, may be used. It is preferable to carry out the reaction continuously to make the reaction proceed smoothly. In order to perform dehydration efficiently, azeotropic dehydration may be performed while flowing hydrogen. In the method in which water is removed by azeotropic dehydration to carry out the reaction, not only the raw material compound but also a solvent may be used as the azeotropic solvent used. When azeotropic dehydration is performed using a solvent, preferred solvents include toluene, xylene, benzene, and the like. The amount of the solvent used is preferably 1 to 2 times the volume of the reaction solution.

In the present invention, it is also possible to remove water by-produced by the reaction out of the reaction system while flowing a gas such as hydrogen. The flow rate of hydrogen used in the present invention may be appropriately selected according to the reaction scale.
On a scale of 5 to 1 L, 0.01 to 30 L / min is preferable, and 0.01 to 30 L / min is preferable.
-10 L / min is more preferred. By setting the flow rate of hydrogen to 0.01 L / min or more, water is easily removed from the system, and the reaction speeds up. Further, when the flow rate of hydrogen is 30 L / min or less, the amount of raw material compounds removed together with water is reduced, which is preferable. However, even in this case, useful components such as unreacted raw materials and products that are removed together with water, for example, after fractionation, removal of water by a liquid separation or a dehydrating agent, are returned to the reaction system again, or are removed. The reaction can be carried out without delay by adding the appropriate amount of raw materials. In addition, the flow of hydrogen may be performed continuously or intermittently during the reaction, but continuous flow is preferable in order to make the reaction proceed smoothly. Further, the hydrogen circulated in the reaction system may be released to the atmosphere as it is, but in order to use hydrogen effectively, hydrogen that has come out of the system is returned to the system again by a circulation line or the like. It is efficient and preferable to use the reaction while circulating and circulating.

Such a method of removing water while flowing hydrogen is advantageous in that there is no reagent to be further added, hydrogen and water can be easily separated, and post-treatment is simple.

[0035]

EXAMPLES Example 1 (Synthesis of Mesoporous Aluminosilicate) Water Glass 25
0 g, 10.8 g of sodium aluminate and 550 ml of water were placed in a 1 L stainless steel beaker, stirred at 70 ° C. for 3 hours, water was evaporated, dried, and calcined at 700 ° C. for 5 hours to obtain 120 g of layered aluminosilicate. Obtained. 300 ml of water was added to 50 g of the obtained layered aluminosilicate, and after stirring, 40 g of cetyldimethylammonium chloride and 1 L of water were added.
After stirring at 3 ° C. for 3 hours, the mixture was stirred for 12 hours while adjusting the pH to 8.5 with 2N HCl. After cooling to room temperature, filtration, washing with water,
It was dried and baked at 700 ° C. for 7 hours. 2N NH ₄ Cl 80
After adding 0 ml and stirring at 50 ° C. for 3 hours, the mixture was filtered, washed with water, and dried, and calcined at 500 ° C. for 2 hours to obtain 38 g of mesoporous aluminosilicate. Elemental analysis by atomic absorption analysis revealed an Al: Si ratio of 4.8: 95.2, XRD analysis revealed a pore diameter of 3.5 nm, and a specific surface area of 750 m ² / g by the BET method.

(Support of palladium on mesoporous aluminosilicate) 2.0 g of palladium chloride was dissolved in 250 ml of 28% aqueous ammonia and 750 ml of water, and the temperature was raised to 50 ° C. 2.0 g of mesoporous aluminosilicate was added, and the mixture was further stirred for 3 hours, filtered, washed with water, dried, and calcined at 550 ° C. for 2 hours to obtain palladium-supported mesoporous aluminosilicate. Elemental analysis by atomic absorption analysis revealed that the catalyst had a palladium loading of 6.7%.

(Production of 1,3-dimethylbutylhexadecyl ether) 500 ml equipped with a hydrogen gas inlet tube and a stirrer
116 g of hexadecyl alcohol (0.5 g
mol), 100 g (1.0 mol) of 4-methyl-2-pentanone and 1.5 g of palladium-supported mesoporous aluminosilicate as a catalyst, and reacted at 150 ° C. for 5 hours under a hydrogen pressure of 9.8 MPa. After completion of the reaction, the catalyst was removed by filtration, and excess 4-methyl-2-pentanone was distilled off under reduced pressure. The product was further purified by distillation under reduced pressure to obtain 153 g (0.47 mol) of the target 1,3-dimethylbutylhexadecyl ether as a colorless and transparent oil. The isolation yield was 94%, and the purity was 99.5% as determined by chromatography.

Comparative Example 1 (Production of 1,3-dimethylbutylhexadecyl ether using a commercially available catalyst) The same as Example 1 except that 2.1 g of a commercially available 5% palladium-supported zeolite was used instead of palladium-supported mesoporous aluminosilicate as a catalyst. The conversion was only 9%.

Comparative Example 2 (Production of 1,3-dimethylbutylhexadecyl ether using a commercially available catalyst) The procedure of Example 1 was repeated except that 2.1 g of a commercially available 5% palladium-supported silica alumina was used instead of palladium-supported mesoporous aluminosilicate as a catalyst. When the reaction was carried out in the same manner, the reaction did not proceed at all.

Example 2 (Synthesis of mesoporous aluminosilicate) 100 ml of water was added to 15 g of a layered aluminosilicate (Si: A1 ratio = 95: 5) obtained in the same manner as in Example 1, and the mixture was stirred and then stirred with cetyldimethylammonium chloride. 12 g, 5.0 g of 1,3,5-trimethylbenzene and 300 ml of water were added, followed by stirring at 70 ° C. for 3 hours, and then stirring for 12 hours while adjusting the pH to 8.5 with 2N HCl.
After cooling to room temperature, filtration, washing with water, and drying were performed at 550 ° C.
For 8 hours. Further, 200 ml of 2N NH ₄ Cl was added, and the mixture was stirred at 50 ° C. for 3 hours, filtered, washed with water and dried, and calcined at 500 ° C. for 2 hours to obtain 14 g of mesoporous aluminosilicate. XRD analysis revealed that the pore size was 4.7 nm.

(Support of palladium on mesoporous aluminosilicate) 0.5 g of palladium chloride was dissolved in 30 ml of 1N aqueous ammonia and 50 ml of water, and the temperature was raised to 50 ° C. 5.0 g of mesoporous aluminosilicate and 50 ml of water were added, and the mixture was further stirred for 3 hours, filtered, washed with water and dried, and calcined at 500 ° C. for 2 hours to obtain 5.0 g of mesoporous aluminosilicate carrying palladium. Elemental analysis by atomic absorption analysis revealed that the catalyst had a palladium loading of 2.1%.

(Production of 1,3-dimethylbutyltetradecyl ether) 500 ml equipped with a hydrogen gas inlet tube and a stirrer
107 g of tetradecyl alcohol (0.5 g
mol), 4-methyl-2-pentanone (100 g, 1.0 mol) and palladium-supported mesoporous aluminosilicate (3.0 g) were charged and reacted at 150 ° C. under a hydrogen pressure of 9.8 MPa for 5 hours. The conversion to dimethylbutylhexadecyl ether was 95%.

Example 3 (Production of octyl glyceryl ether) 92 g (1.0 mol) of glycerin and 200 g (1.6 mol) of octanal were placed in a 500 ml autoclave equipped with a hydrogen gas inlet tube and a stirrer.
And further charged with 5.0 g of the mesoporous aluminosilicate supported on palladium obtained in Example 1 as a catalyst,
When the reaction was performed at 150 ° C for 10 hours under a hydrogen pressure of 9.8 MPa,
The conversion of glycerin reached 90%. After completion of the reaction, excess aldehyde was distilled off under reduced pressure, and further washed with water to obtain 220 g.
Octyl glyceryl ether was obtained as a colorless transparent oil. According to gas chromatography analysis, the purity of the formed octyl glyceryl ether was 94% and contained 6% of dioctyl glyceryl ether.

Comparative Example 3 (Production of octyl glyceryl ether using a commercially available catalyst)
Commercially available 5% palladium on zeolite is used as catalyst instead of palladium on mesoporous aluminosilicate
When the reaction was carried out in the same manner as in Example 3 except that 5.0 g was used, the conversion was only 5%.

[0045]

According to the present invention, ethers useful for various uses such as solvents, cosmetics, detergent compositions, lubricants, and emulsifiers can be easily and inexpensively produced from hydroxy compounds and carbonyl compounds.

Claims (6)

[Claims] 1. A method for producing an ether, wherein a hydroxy compound and a carbonyl compound are reacted in a hydrogen atmosphere in the presence of a catalyst to produce an ether, wherein a palladium catalyst supported on a mesoporous aluminosilicate is used as a catalyst. 2. The method according to claim 1, wherein the pore diameter of the mesoporous aluminosilicate is 2 to 10 nm. 3. The process according to claim 1, wherein the reaction is carried out by removing by-produced water. 4. A hydroxy compound represented by the following general formula (1): [In the formula, R ¹ represents a linear or branched alkyl group or alkenyl group having 1 to 40 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms, and A represents an alkylene group having 2 to 12 carbon atoms. , N A may be the same or different. n
Represents a number from 0 to 30. The method according to any one of claims 1 to 3, which is a compound represented by the formula: 5. The process according to claim 1, wherein the hydroxy compound is a linear or branched polyhydric alcohol having 2 to 40 carbon atoms. 6. A carbonyl compound represented by the general formula (2): [Wherein, R ² and R ³ represent a hydrogen atom, a linear or branched alkyl or alkenyl group having 1 to 20 carbon atoms, and R ² and R ³ may be the same or different. Also, R ²
And R ³ together may form a cyclic structure in which an alkylene or alkenylene group having 2 to 20 carbon atoms is formed. ]
The method according to any one of claims 1 to 5, which is a compound represented by the formula: