Method for producing ether

Abstract

Provided is a method with which it is possible to produce a corresponding ether from a carboxylic acid ester, and in which the reaction product and catalyst can be separated easily, without releasing large amounts of salt waste or harmful waste.　A method for producing an ether, involving reducing a carboxylic acid ester by molecular hydrogen in the presence of the following catalyst to produce a corresponding ether in which the -C(=O)O- group of the carboxylic acid ester has been converted into a -CH2O- group.　Catalyst: A catalyst in which the following M1 and M2 are supported as metal species on the following support. M1: platinum, ruthenium, rhodium, palladium, or iridium. M2: molybdenum, rhenium, tungsten, or vanadium. Support: zirconium oxide, titanium oxide, cerium oxide, or hydroxyapatite.

Description

[Technical field]

[0001] The present disclosure relates to a method for reducing a carboxylic acid ester to produce a corresponding ether, and an ester reduction catalyst. This application claims priority from Japanese Patent Application No. 2020-088155, filed on May 20, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] Long-chain alkyl ethers derived from fatty acids have relatively low melting points and viscosities, making them useful compounds for fragrances, lubricants, surfactants, cosmetics, etc. Asymmetric alkyl ethers are mainly prepared by the Williamson ether synthesis and Ullman ether reaction. However, these methods have problems such as requiring the use of organic halides and strong bases and producing salt waste.

[0003] Direct reduction of esters has attracted attention because it allows the easy synthesis of unsymmetrical ethers. However, most of the reported reduction reactions from esters to ethers use LiAlH4 or silane as reducing agents, which has problems such as the generation of hazardous waste. Therefore, there is a need to establish a reaction route from esters to ethers using inexpensive molecular hydrogen as a reducing agent that produces only clean water as a by-product.

[0004] In 2015, Beller et al. succeeded in the reduction of esters to ethers for the first time in the world using molecular hydrogen as a reducing agent (Non-Patent Document 1). Using Ruthenium / triphos and Al(OTf)3 as catalysts, ethers were synthesized under reaction conditions of a reaction temperature of 130-160°C and a hydrogen pressure of 4-6 MPa. However, because the catalyst is a complex catalyst, it is difficult to separate and recover the catalyst. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Angew. Chem. Int. Ed. 2015, 54, 5196-5200 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present disclosure is to provide a process for producing a corresponding ether from a carboxylic acid ester, which allows easy separation of the reaction products and catalyst and does not generate a large amount of salt waste or hazardous waste materials. Another object of the present disclosure is to provide a heterogeneous catalyst capable of reducing carboxylic acid esters with molecular hydrogen to produce the corresponding ethers. [Means for solving the problem]

[0007] As a result of intensive research aimed at solving the above problems, the present inventors have found that by using a specific catalyst, it is possible to produce a corresponding ether from a carboxylic acid ester and molecular hydrogen, without easily separating the reaction product from the catalyst, and without discharging a large amount of salt waste or harmful waste, and have completed the present disclosure.

[0008] That is, the present disclosure provides a method for producing an ether, comprising reducing a carboxylate ester with molecular hydrogen in the presence of a catalyst described below to produce a corresponding ether in which a -C(=O)O- group of the carboxylate ester is converted to a -CHO- group. Catalyst: The metal species is as follows: M 1 and M. 2 A catalyst supported on the following carrier: M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite

[0009] The carboxylic acid ester is, for example, a compound represented by the following formula (1): [ka] (In the formula, R 1 represents a hydrogen atom or an organic group having a carbon atom adjacent to the carbonyl group in the formula, and R 2 represents an organic group having a carbon atom at the bonding site with the oxygen atom in the formula. It is a compound represented by the formula:

[0010] The catalyst contains M as a metal species. 2 , M as the metal species 1 The content may be within a range of 0.05 to 1 mol per mol of the compound.

[0011] In addition, the present disclosure relates to the following metal species: 1 and M. 2 The present invention provides an ester reduction catalyst comprising the following catalyst supported on a support: M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite Effect of the Invention

[0012] According to the present disclosure, a carboxylic acid ester can be reduced with molecular hydrogen to produce the corresponding ether without discharging a large amount of salt waste or harmful waste. In addition, since the catalyst is a heterogeneous catalyst, it is easy to separate the reaction product from the catalyst. In addition, the reaction can be carried out not only in a solvent but also in a solvent-free state. Furthermore, not only symmetrical ethers but also asymmetrical ethers can be synthesized, and the range of application is wide. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (catalyst) In this disclosure, the following metal species is used: 1 and M.2 At least one of the catalysts supported on the following carriers is used. M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite

[0014] M supported on the carrier 1 and M. 2 may be a metal element or a metal compound such as a metal salt, a metal oxide, a metal hydroxide, or a metal complex. 1 is preferably a single unit, and M 2 is preferably an oxide. 1 Among these, platinum is particularly preferred, and the metal species M 2 Among these, molybdenum is particularly preferred. 1 , M 2 Each of these may be used alone or in combination of two or more.

[0015] M 1 The amount of M supported (in terms of metal) is, for example, 0.01 to 10 mmol / g, preferably 0.05 to 5 mmol / g, and particularly preferably 0.1 to 1 mmol / g, based on the carrier. 1 By setting the amount of used within the above range, excellent catalytic activity and reaction selectivity can be obtained.

[0016] M 2 The amount of M supported (in terms of metal) is, for example, 0.001 to 1 mmol / g, preferably 0.01 to 0.5 mmol / g, and particularly preferably 0.01 to 0.1 mmol / g, based on the carrier. 2 By setting the amount of used within the above range, excellent catalytic activity and reaction selectivity can be obtained.

[0017] In the present disclosure, the catalyst is 1 and M. 2It is believed that the catalytically active sites are located at the interface of M 1 M per mole (metal equivalent) 2 The supported amount (in terms of metal) is, for example, 0.05 to 1 mol, preferably 0.1 to 0.5 mol, and more preferably 0.15 to 0.35 mol.

[0018] In the present disclosure, the catalyst is 1 and M. 2 A third metal species other than the above may be supported on the support. The amount of the third metal species supported (in terms of metal) is M 1 and M. 2 With respect to the total amount of the supported metal species (converted into metal), the amount is, for example, 200 mol % or less, preferably 150 mol % or less, more preferably 100 mol % or less, further preferably 50 mol % or less, particularly preferably 10 mol % or less, most preferably 5 mol % or less, and particularly preferably 1 mol % or less. If the amount of the supported third metal species exceeds the above range, the effect of the present invention tends to be difficult to obtain, possibly due to a decrease in catalytic active sites.

[0019] In this disclosure, M 1 and M. 2 By supporting it on a carrier, M 1 and M. 2 This increases the interfacial area and exposes many catalytically active sites.

[0020] In the present disclosure, zirconium oxide, titanium oxide, cerium oxide, or hydroxyapatite (HAP) is used as the catalyst carrier. By using zirconium oxide, titanium oxide, cerium oxide, or hydroxyapatite as the catalyst carrier, good catalytic activity and reaction selectivity, as well as excellent durability, can be obtained. Zirconium oxide is particularly preferred as the catalyst carrier.

[0021] The specific surface area of ​​the support (zirconium oxide, titanium oxide, cerium oxide, or hydroxyapatite) is, for example, 5 to 250 m from the viewpoint of catalytic activity. 2 / g, preferably 10 to 100m 2 / g.

[0022] As the hydroxyapatite, for example, a commercially available product such as "Tricalcium Phosphate" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) can be used.

[0023] The catalyst of the present disclosure can be suitably used as an ester reduction catalyst for reducing a carboxylic acid ester to obtain a corresponding ether in which the -C(=O)O- group of the carboxylic acid ester is converted to a -CHO- group.

[0024] In this disclosure, M 1 and M. 2 Since a catalyst supported on a carrier is used, after the reaction is completed, the catalyst and the reaction product can be easily separated by physical separation means such as filtration, centrifugation, etc. In addition, the catalyst separated from the reaction product and recovered can be reused as is or after washing, drying, etc. In addition, since zirconium oxide or hydroxyapatite is used as the carrier, the catalyst has excellent durability and is inhibited from eluting into the reaction solution, so that good catalytic activity can be maintained even if it is repeatedly reused or operated continuously for a long period of time.

[0025] In the present disclosure, as described above, although a relatively expensive metal species is used, the catalyst can be used repeatedly (in the case of a continuous reaction, it can be used for a long period of time), thereby reducing the production cost of the ether.

[0026] (Catalyst Preparation Method) The catalysts of the present disclosure can be prepared, for example, by impregnation methods.

[0027] The impregnation method is a method in which a support is immersed in a solution (e.g., an aqueous solution) obtained by dissolving a compound containing the above-mentioned metal species (=metal compound) in a solvent (e.g., water, etc.) to impregnate the support with the metal compound, and then dried and calcined to support the metal species on the support. The amount of the metal species supported can be controlled by adjusting the concentration of the metal compound in the solution, the immersion time of the support, etc.

[0028] The catalyst of the present disclosure is a carrier having a metal species M 1 A solution containing metal species M 1 A solution obtained by dissolving a compound containing M in a solvent. 1 (sometimes called "containing solution") and M 2 A solution containing (M 2 A solution obtained by dissolving a compound containing M in a solvent. 2 In the method of impregnating the carrier with the M-containing solution (sometimes called the "sequential impregnation method"), 1 Containing solution and M 2 The catalyst can be prepared by simultaneously impregnating the catalyst-containing solutions (=co-impregnation method). When preparing the catalyst by the co-impregnation method, M 1 Containing solution and M 2 The carrier is impregnated in the mixture of the containing solutions, and then dried and calcined. When the catalyst is prepared by the sequential impregnation method, the carrier is 1 Containing solution and M 2 The sample is immersed in one of the solutions containing M 1 Containing solution and M 2 The material may be immersed in the other of the solutions containing the metal oxide, dried, and then calcined.

[0029] For example, M 1 Pt and M as 2 The catalyst in which Mo is supported on the support by the co-impregnation method (e.g., Pt-Mo / support) is prepared by co-impregnation of Pt compounds (e.g., HPtCl, etc.) and Mo compounds [e.g., (NH)MoO 24 The support (zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite) is immersed in a solution obtained by dissolving cerium oxide, 4H2O, etc., in water, and then the water is distilled off, the support is dried, and then calcined to prepare the support.

[0030] Also, for example, M 1 Pt and M as 2A catalyst in which Mo is supported on a support in the order of Mo-Pt (e.g., Pt / Mo / support) is prepared by first heating the support (zirconium oxide, titanium oxide, cerium oxide, or hydroxyapatite) to a Mo compound [e.g., (NH4)6Mo7O 24 The substrate can be prepared by immersing the substrate in a solution obtained by dissolving platinum compound (e.g., HPtCl) in water, evaporating the water, drying the substrate, immersing the substrate in a solution obtained by dissolving platinum compound (e.g., HPtCl) in water, evaporating the water, drying the substrate, and then calcining the substrate.

[0031] The temperature when the support is immersed in the solution is, for example, about 10 to 80°C.

[0032] The time for immersing the support in the solution is, for example, 1 to 30 hours, and preferably 1 to 5 hours.

[0033] The calcination is carried out, for example, using a muffle furnace. The calcination temperature is, for example, 300°C or higher and lower than 700°C. The calcination time is, for example, 1 to 5 hours. If the calcination temperature exceeds the above range, the catalytic activity tends to decrease rapidly, possibly due to aggregation of the metal species supported on the support. From the viewpoint of increasing the catalytic activity, the calcination temperature is preferably 350 to 650°C, particularly preferably 400 to 550°C, and particularly preferably 450 to 550°C.

[0034] After the calcination, a reduction treatment may be further carried out. The reducing agent used in the reduction treatment may be, for example, hydrogen (H2).

[0035] The reduction treatment temperature and time are, for example, 0 to 600° C. (preferably 100 to 200° C.) and about 0.5 to 5 hours (preferably 0.5 to 2 hours).

[0036] The catalyst obtained by the above-mentioned preparation method may then be subjected to a washing treatment (washing with water, an organic solvent, etc.), a drying treatment (drying by vacuum drying, etc.), and the like.

[0037] (substrate) In the present disclosure, a carboxylate ester is used as a substrate in the method for producing an ether. The carboxylate ester may be an ester of a carboxylic acid selected from the group consisting of an aliphatic carboxylic acid, an alicyclic carboxylic acid, an aromatic carboxylic acid, and a heterocyclic carboxylic acid, and a hydroxyl group-containing compound selected from the group consisting of an aliphatic alcohol, an alicyclic alcohol, an aromatic alcohol, a heterocyclic alcohol, and a phenol. The carboxylate ester may be a compound having one ester bond (-C(=O)O-) in one molecule, or may be a compound having two or more ester bonds in one molecule.

[0038] Representative examples of the carboxylate ester include compounds represented by the following formula (1). [ka] (In the formula, R 1 represents a hydrogen atom or an organic group having a carbon atom adjacent to the carbonyl group in the formula, and R 2 represents an organic group having a carbon atom at the bonding site with the oxygen atom in the formula.

[0039] R 1 "An organic group having a carbon atom adjacent to the carbonyl group in the formula" in 2 Examples of the "organic group having a carbon atom at the bonding site to the oxygen atom in the formula" include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, and a group in which two or more of these are bonded with or without an ether bond, a thioether bond, -NH-, -C(=O)-, and -C(=S)-.

[0040] Examples of the aliphatic hydrocarbon group include linear or branched alkyl groups having 1 to 20 carbon atoms (preferably, 1 to 12 carbon atoms), such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups; linear or branched alkenyl groups having 2 to 20 carbon atoms (preferably, 2 to 12 carbon atoms), such as vinyl, allyl, propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, and 2-pentenyl groups.

[0041] Examples of the alicyclic hydrocarbon group include cycloalkyl groups having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms), such as cyclopentyl, cyclohexyl, and cycloheptyl groups; and cycloalkenyl groups having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms), such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cyclooctenyl groups.

[0042] Examples of the aromatic hydrocarbon group include aryl groups having 6 to 20 carbon atoms, such as phenyl, biphenyl, naphthyl, binaphthyl, and anthracenyl groups.

[0043] Examples of the heterocyclic group include aromatic or non-aromatic heterocyclic groups having one or more heteroatoms selected from the group consisting of oxygen atoms, sulfur atoms, and nitrogen atoms, such as a 2-furyl group, a 2-thienyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-quinolyl group, a 4-piperidinyl group, and a 2-morpholinyl group.

[0044] The aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the heterocyclic group may have a substituent. Examples of such a substituent include, for example, 1-5 Alkyl group, C 1-5 Alkoxy group, C 6-10 Aryl group, C 6-10 Aryloxy group, C 7-11 Aralkyl group, C 7-11 Aralkyloxy group, oxo group, halogen atom, C 1-5Examples include haloalkyl groups.

[0045] [Method of producing ether] In the method for producing an ether according to the present disclosure, a carboxylic acid ester substrate is reduced with molecular hydrogen in the presence of the above catalyst to convert the -C(=O)O- group of the ester to a -CHO- group, thereby producing the corresponding ether.

[0046] In the method for producing an ether according to the present disclosure, an ether is obtained according to the substrate (carboxylate) used. For example, when a carboxylate represented by the above formula (1) is used as a substrate, an ether represented by the following formula (2) is obtained. In this way, by selecting the substrate, various symmetrical or asymmetrical ethers can be produced. [ka] (In the formula, R 1 , R 2 is the same as above)

[0047] There are two possible reaction mechanisms for converting carboxylic acid esters to ethers: direct deoxygenation, and hydrolysis of the carboxylic acid ester to generate a carboxylic acid and an alcohol (alcohol-1), reduction of the carboxylic acid to generate an alcohol (alcohol-2), and dehydration of the alcohol-2 with the alcohol-1 to generate an ether. However, since the corresponding ether was not generated when a carboxylic acid and an alcohol were used as raw materials, it is believed that this reaction proceeds via a mechanism in which deoxygenation occurs directly from the ester.

[0048] The amount of the catalyst used (calculated as platinum, ruthenium, rhodium, palladium or iridium metal contained in the catalyst) is, for example, 0.01 to 30 mol %, preferably 0.1 to 10 mol %, particularly preferably 0.5 to 5 mol %, and most preferably 1 to 5 mol %, relative to the substrate.

[0049] The amount of the catalyst used (calculated as molybdenum, rhenium, tungsten or vanadium metal contained in the catalyst) is, for example, 0.01 to 10 mol %, preferably 0.05 to 5 mol %, and particularly preferably 0.1 to 2 mol %, based on the substrate.

[0050] When the catalyst is used within the above range, the substrate can be efficiently reduced to produce the corresponding ether in good yield.

[0051] The reduction reaction using hydrogen is carried out, for example, by a method of carrying out the reaction in a hydrogen atmosphere or by a method of bubbling hydrogen gas.

[0052] In the present disclosure, the use of the above catalyst allows the reduction of -C(=O)O- groups to -CHO- groups to proceed quickly. The hydrogen pressure during the reduction reaction is, for example, 0.1 to 20 MPa, preferably 1 to 15 MPa, more preferably 2 to 10 MPa, and particularly preferably 2.5 to 8 MPa.

[0053] The reaction temperature of the reduction reaction is, for example, 20 to 250° C., preferably 50 to 230° C., more preferably 70 to 220° C. (e.g., 80 to 180° C.), and particularly preferably 120 to 200° C. (e.g., 90 to 160° C.). By setting the reaction temperature within the above range, the reduction reaction of the substrate is promoted, and decomposition of the target product can be suppressed, making it possible to obtain the ether in good yield.

[0054] The reaction time for the reduction reaction is, for example, 0.5 to 200 hours, preferably 0.6 to 36 hours, more preferably 1 to 15 hours, and particularly preferably 2 to 10 hours. By setting the reaction time within the above range, the reduction reaction of the substrate can be promoted and decomposition of the target product can be suppressed, allowing the ether to be obtained in good yield.

[0055] The reduction reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

[0056] The reduction reaction is preferably carried out in a liquid phase, that is, the reduction reaction in the present invention is preferably a liquid phase reaction.

[0057] The reduction reaction can be carried out without a solvent or can be carried out using a solvent. Examples of the solvent include ether solvents (chain ethers or cyclic ethers) such as diethyl ether, diisopropyl ether, dibutyl ether, and 1,4-dioxane; hydrocarbon solvents (aliphatic hydrocarbons, alicyclic hydrocarbons, or aromatic hydrocarbons) such as hexane, octane, decane, dodecane, cyclohexane, and toluene; halogenated hydrocarbon solvents such as 1,2-dichloroethane and dichloromethane; alcohols such as ethanol and isopropyl alcohol; and water. These can be used alone or in combination of two or more. Note that when water is used as a solvent, the by-production of alcohol tends to increase.

[0058] The amount of the solvent used can be appropriately selected depending on the type of substrate, etc. The concentration of the substrate in the total solution used in the reaction (initial concentration of the substrate in the case of a batchwise reaction) is, for example, 0.01 to 100% by weight, preferably 0.1 to 50% by weight, and more preferably 1 to 20% by weight.

[0059] In the method for producing ethers according to the present disclosure, a heterogeneous catalyst is used, so that after the reaction is completed, the product and the catalyst can be easily separated and collected by filtration or the like. Therefore, the catalyst can be easily reused. In addition, the main by-product is clean water, and there is no need to discharge a large amount of salt waste or harmful waste.

[0060] After completion of the reaction, the reaction product can be separated and purified by a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

[0061] In the disclosed method for producing an ether, a substrate carboxylic acid ester can be converted to the corresponding ether.

[0062] Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. In addition, each configuration in each embodiment and their combinations are merely examples, and addition, omission, and other modifications of configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims. EXAMPLES

[0063] The present disclosure will now be described more specifically with reference to examples.

[0064] Preparation Example 1 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0088 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25°C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (1) [Pt / Mo / ZrO2, Pt loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pt (molar ratio) = 0.25].

[0065] Preparation Example 2 (Catalyst preparation: co-impregnation method) 0.0820g of HPtCl6 and (NH)MoO 24 0.0088 g of 4H2O was dissolved in 50 mL of water, and the resulting solution was cooled to room temperature (25°C) and cooled to room temperature. 21.008 g of the catalyst (Pt-Mo / ZrO2, Pt loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pt (molar ratio) = 0.25) was immersed in the catalyst (2) for 4 hours. After immersion, water was distilled off under reduced pressure using a rotary evaporator. This resulted in a powder. The resulting powder was then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (2) [Pt-Mo / ZrO2, Pt loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pt (molar ratio) = 0.25].

[0066] Preparation Example 3 (Catalyst preparation: sequential impregnation method) 0.0820 g of HPtCl was dissolved in 50 mL of water to obtain a Pt solution, and zirconium oxide (ZrO, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was dissolved in water using a solvent such as (NH4)6Mo7O 24 The catalyst was immersed in a solution obtained by dissolving 0.0088 g of 4H2O in 50 mL of water at room temperature (25°C) for 4 hours. After immersion, the water was removed under reduced pressure using a rotary evaporator, the catalyst was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (3) [Mo / Pt / ZrO2, Pt loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pt (molar ratio) = 0.25].

[0067] Preparation Example 4 (Catalyst preparation: impregnation method) (NH4)6Mo7O 24 0.0088 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25°C). 21.001 g of Mo / ZrO2 (Mo loading: 0.05 mmol / g, Catalysis Society reference catalyst "JRC-ZRO-8") was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the mixture was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (4) [Mo / ZrO2, Mo loading: 0.05 mmol / g (support)].

[0068] Preparation Example 5 (Catalyst preparation: sequential impregnation method) 0.0134 g of (NH4)ReO4 was dissolved in 50 mL of water to obtain a Re solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (5) [Pt / Re / ZrO2, Pt loading: 0.2 mmol / g (support), Re loading: 0.05 mmol / g (support), Re / Pt (molar ratio) = 0.25].

[0069] Preparation Example 6 (Catalyst preparation: sequential impregnation method) (NH4) 10 In a W solution obtained by dissolving 0.0128 g of H2(W2O7) in 50 mL of water, zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (6) [Pt / W / ZrO2, Pt loading: 0.2 mmol / g (support), W loading: 0.05 mmol / g (support), W / Pt (molar ratio) = 0.25].

[0070] Preparation Example 7 (Catalyst preparation: sequential impregnation method) 0.0058 g of NH4VO3 was dissolved in 50 mL of water to obtain a solution of zirconium oxide (ZrO2, specific surface area: 22.1 m) at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (7) [Pt / V / ZrO2, Pt loading: 0.2 mmol / g (support), V loading: 0.05 mmol / g (support), V / Pt (molar ratio) = 0.25].

[0071] Preparation Example 8 (Catalyst preparation: sequential impregnation method) 0.0134 g of (NH4)ReO4 was dissolved in 50 mL of water to obtain a Re solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Ru solution obtained by dissolving 0.0415 g of RuCl3 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the material was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (8) [Ru / Re / ZrO2, Ru loading amount: 0.2 mmol / g (support), Re loading amount: 0.05 mmol / g (support), Re / Ru (molar ratio) = 0.25].

[0072] Preparation Example 9 (Catalyst preparation: sequential impregnation method) (NH4) 10 In a W solution obtained by dissolving 0.0128 g of H2(W2O7) in 50 mL of water, zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Ru solution obtained by dissolving 0.0415 g of RuCl3 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the material was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (9) [Ru / W / ZrO2, Ru loading amount: 0.2 mmol / g (support), W loading amount: 0.05 mmol / g (support), W / Ru (molar ratio) = 0.25].

[0073] Preparation Example 10 (Catalyst preparation: sequential impregnation method) 0.0058 g of NH4VO3 was dissolved in 50 mL of water to obtain a solution of zirconium oxide (ZrO2, specific surface area: 22.1 m) at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. Water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Ru solution obtained by dissolving 0.0415 g of RuCl3 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the material was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (9) [Ru / V / ZrO2, Ru loading amount: 0.2 mmol / g (support), V loading amount: 0.05 mmol / g (support), V / Ru (molar ratio) = 0.25].

[0074] Preparation Example 11 (Catalyst preparation: sequential impregnation method) 0.0134 g of (NH4)ReO4 was dissolved in 50 mL of water to obtain a Re solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Rh solution obtained by dissolving 0.0419 g of RhCl3 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the resulting mixture was dried at 110° C. and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (11) [Rh / Re / ZrO2, Rh loading: 0.2 mmol / g (support), Re loading: 0.05 mmol / g (support), Re / Rh (molar ratio) = 0.25].

[0075] Preparation Example 12 (Catalyst preparation: sequential impregnation method) 0.0058 g of NH4VO3 was dissolved in 50 mL of water to obtain a solution of zirconium oxide (ZrO2, specific surface area: 22.1 m) at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Rh solution obtained by dissolving 0.0419 g of RhCl3 in 50 mL of water at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (12) [Rh / V / ZrO2, Rh loading amount: 0.2 mmol / g (support), V loading amount: 0.05 mmol / g (support), V / Rh (molar ratio) = 0.25].

[0076] Preparation Example 13 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0088 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25°C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pd solution obtained by dissolving 0.0449 g of Pd(OAc)2 in 50 mL of acetone at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (13) [Pd / Mo / ZrO2, Pd loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pd (molar ratio) = 0.25].

[0077] Preparation Example 14 (Catalyst preparation: sequential impregnation method) (NH4) 10 In a W solution obtained by dissolving 0.0128 g of H2(W2O7) in 50 mL of water, zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pd solution obtained by dissolving 0.0449 g of Pd(OAc)2 in 50 mL of acetone at room temperature (25° C.) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (14) [Pd / W / ZrO2, Pd loading: 0.2 mmol / g (support), W loading: 0.05 mmol / g (support), W / Pd (molar ratio) = 0.25].

[0078] Preparation Example 15 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0088 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25°C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in an Ir solution obtained by dissolving 0.0814 g of H2IrCl6 in 50 mL of water at room temperature (25°C) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (15) [Ir / Mo / ZrO2, Ir loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Ir (molar ratio) = 0.25].

[0079] Preparation Example 16 (Catalyst preparation: sequential impregnation method) 0.0134 g of (NH4)ReO4 was dissolved in 50 mL of water to obtain a Re solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in an Ir solution obtained by dissolving 0.0814 g of H2IrCl6 in 50 mL of water at room temperature (25°C) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (16) [Ir / Re / ZrO2, Ir loading: 0.2 mmol / g (support), Re loading: 0.05 mmol / g (support), Re / Ir (molar ratio) = 0.25].

[0080] Preparation Example 17 (Catalyst preparation: sequential impregnation method) (NH4) 10 In a W solution obtained by dissolving 0.1530 g of H2(W2O7) in 50 mL of water, zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25 °C). 2 1.0 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in an Ir solution obtained by dissolving 0.0814 g of H2IrCl6 in 50 mL of water at room temperature (25°C) for 4 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the product was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (17) [Ir / W / ZrO2, Ir loading: 0.2 mmol / g (support), W loading: 0.05 mmol / g (support), W / Ir (molar ratio) = 0.25].

[0081] Preparation Example 18 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 1.0 g of hydroxyapatite (HAP, product name "tricalcium phosphate", Fujifilm Wako Pure Chemical Industries, Ltd.) was immersed in Mo solution obtained by dissolving 0.0088 g of 4H2O in 50 mL of water for 4 hours at room temperature (25°C). After immersion, water was removed under reduced pressure using a rotary evaporator, and the sample was dried at 110°C. After drying, the hydroxyapatite was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water for 4 hours at room temperature (25°C). After immersion, water was removed under reduced pressure using a rotary evaporator, the mixture was dried at 110°C, and then calcined in an air atmosphere at 500°C for 3 hours in a muffle furnace to obtain catalyst (18) [Pt / Mo / HAP, Pt loading: 0.2 mmol / g (support), Mo loading: 0.05 mmol / g (support), Mo / Pt (molar ratio) = 0.25].

[0082] Preparation Example 19 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0066 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and zirconium oxide (ZrO2, specific surface area: 22.1 m) was added at room temperature (25°C). 2 1.5 g of the catalyst (JRC-ZRO-8, Catalysis Society reference catalyst) was immersed for 12 hours. After immersion, water was removed using a rotary evaporator, and the mixture was dried at 110°C. After drying, the zirconium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 12 hours. After immersion, water was removed using a rotary evaporator, the product was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (19) [Pt / Mo / ZrO2, Pt loading: 0.13 mmol / g (support), Mo loading: 0.025 mmol / g (support), Mo / Pt (molar ratio) = 0.19].

[0083] Preparation Example 20 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0066 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and titanium oxide (TiO2, specific surface area: 18.0 m) was added at room temperature (25°C). 2 1.8 g of TiO2 (1.0 g / g, Catalysis Society reference catalyst "JRC-TiO-2") was immersed for 12 hours. After immersion, water was removed using a rotary evaporator and the sample was dried at 110°C. After drying, the titanium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 12 hours. After immersion, water was removed using a rotary evaporator, the sample was dried at 110° C., and then calcined in an air atmosphere in a muffle furnace at 500° C. for 3 hours to obtain catalyst (20) [Pt / Mo / TiO2, Pt loading: 0.11 mmol / g (support), Mo loading: 0.021 mmol / g (support), Mo / Pt (molar ratio) = 0.19].

[0084] Preparation Example 21 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 Hydroxyapatite (HAP, product name "tricalcium phosphate", Fujifilm Wako Pure Chemical Industries, Ltd.) (0.56 g) was immersed in Mo solution obtained by dissolving 0.0066 g of 4H2O in 50 mL of water for 12 hours at room temperature (25°C). After immersion, water was removed under reduced pressure using a rotary evaporator, and the sample was dried at 110°C. After drying, the hydroxyapatite was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25° C.) for 12 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the mixture was dried at 110° C., and then calcined in an air atmosphere at 500° C. in a muffle furnace for 3 hours to obtain catalyst (21) [Pt / Mo / HAP, Pt loading: 0.36 mmol / g (support), Mo loading: 0.067 mmol / g (support), Mo / Pt (molar ratio) = 0.19].

[0085] Preparation Example 22 (Catalyst preparation: sequential impregnation method) (NH4)6Mo7O 24 0.0066 g of 4H2O was dissolved in 50 mL of water to obtain a Mo solution, and cerium oxide (CeO2, specific surface area: 123.1 m) was added to the solution at room temperature (25°C). 2 0.27 g of the catalyst (JRC-CEO-2, Catalysis Society reference catalyst) was immersed for 12 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, and the sample was dried at 110°C. After drying, the cerium oxide was immersed in a Pt solution obtained by dissolving 0.0820 g of HPtCl6 in 50 mL of water at room temperature (25°C) for 12 hours. After immersion, water was removed under reduced pressure using a rotary evaporator, the mixture was dried at 110°C, and then calcined in an air atmosphere in a muffle furnace at 500°C for 3 hours to obtain catalyst (22) [Pt / Mo / CeO2, Pt loading: 0.74 mmol / g (support), Mo loading: 0.139 mmol / g (support), Mo / Pt (molar ratio) = 0.19].

[0086] Example 1 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol of methyl hexanoate as a substrate, 100 mg of catalyst (1) (Pt / Mo / ZrO2) [2 mol% Pt, 0.5 mol% Mo (metal conversion) relative to the substrate], and 3 mL of diisopropyl ether were charged and reacted at 180°C for 3 hours under a hydrogen pressure of 5 MPa to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 91%, and hexyl methyl ether, 1-hexanol, and hexane were produced (see the following formula). The yield of hexyl methyl ether was 46%, the yield of 1-hexanol was 2%, and the yield of hexane was 30%.

[0087] [ka]

[0088] Example 2 The same procedure as in Example 1 was carried out, except that catalyst (2) (Pt-Mo / ZrO2) was used instead of catalyst (1). As a result, the conversion rate of the substrate was 89%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 40%, the yield of 1-hexanol was 2%, and the yield of hexane was 25%.

[0089] Example 3 The same procedure as in Example 1 was carried out, except that catalyst (3) (Mo / Pt / ZrO2) was used instead of catalyst (1). As a result, the conversion rate of the substrate was 91%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 42%, the yield of 1-hexanol was 3%, and the yield of hexane was 26%.

[0090] Example 4 The same procedure as in Example 1 was carried out, except that the reaction temperature was 140° C. As a result, the conversion rate of the substrate was 95%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 59%, the yield of 1-hexanol was 1%, and the yield of hexane was 22%.

[0091] Comparative Example 1 The same procedure as in Example 1 was carried out, except that catalyst (4) (Mo / ZrO2) was used instead of catalyst (1) and the reaction temperature was 140°C. As a result, the conversion rate of the substrate was 1%. Hexyl methyl ether, 1-hexanol, and hexane were not produced.

[0092] Example 5 The same procedure as in Example 1 was carried out except that the reaction time was 1 hour. As a result, the conversion rate of the substrate was 76%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 42%, the yield of 1-hexanol was 2%, and the yield of hexane was 33%.

[0093] Example 6 The same procedure as in Example 1 was carried out, except that the reaction time was 6 hours. As a result, the conversion rate of the substrate was 97%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 45%, the yield of 1-hexanol was 1%, and the yield of hexane was 14%.

[0094] Example 7 The same procedure as in Example 1 was carried out, except that the reaction time was 12 hours. As a result, the conversion rate of the substrate was 97%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 46%, the yield of 1-hexanol was 2%, and the yield of hexane was 46%.

[0095] Example 8 The same procedure as in Example 1 was carried out, except that the reaction temperature was 160° C. As a result, the conversion rate of the substrate was 89%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 49%, the yield of 1-hexanol was 2%, and the yield of hexane was 22%.

[0096] Example 9 The same procedure as in Example 1 was carried out, except that the reaction temperature was 150° C. As a result, the conversion rate of the substrate was 96%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 48%, the yield of 1-hexanol was 1%, and the yield of hexane was 28%.

[0097] Example 10 The same procedure as in Example 1 was carried out, except that the reaction temperature was 130° C. As a result, the conversion rate of the substrate was 94%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 50%, the yield of 1-hexanol was 2%, and the yield of hexane was 33%.

[0098] Example 11 The same procedure as in Example 1 was carried out, except that the reaction temperature was 120° C. As a result, the conversion rate of the substrate was 77%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 49%, the yield of 1-hexanol was 7%, and the yield of hexane was 19%.

[0099] Example 12 The same procedure as in Example 1 was carried out, except that the reaction temperature was 100° C. As a result, the conversion rate of the substrate was 63%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 35%, the yield of 1-hexanol was 12%, and the yield of hexane was 6%.

[0100] Example 13 The same procedure as in Example 1 was carried out, except that the reaction temperature was 80° C. As a result, the conversion rate of the substrate was 33%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 16%, the yield of 1-hexanol was 10%, and the yield of hexane was 3%.

[0101] Example 14 The same procedure as in Example 1 was carried out, except that the solvent was changed from diisopropyl ether to diethyl ether and the reaction time was changed to 1 hour. As a result, the conversion rate of the substrate was 91%, and hexyl methyl ether and 1-hexanol were produced. Hexane was not produced. The yield of hexyl methyl ether was 53%, and the yield of 1-hexanol was 1%.

[0102] Example 15 The same procedure as in Example 1 was carried out except that no solvent was used. As a result, the conversion rate of the substrate was 99%, and hexyl methyl ether and hexane were produced. 1-hexanol was not produced. The yield of hexyl methyl ether was 59%, and the yield of hexane was 39%.

[0103] Example 16 The same procedure as in Example 1 was carried out, except that the solvent was changed from diisopropyl ether to octane and the reaction time was changed to 12 hours. As a result, the conversion rate of the substrate was 82%, and hexyl methyl ether, 1-hexanol, and hexane were produced. The yield of hexyl methyl ether was 29%, the yield of 1-hexanol was 6%, and the yield of hexane was 38%.

[0104] Example 17 The same procedure as in Example 1 was carried out, except that catalyst (5) (Pt / Re / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 56%, and hexyl methyl ether, 1-hexanol, and hexyl hexanoate were produced. The yield of hexyl methyl ether was 8%, the yield of 1-hexanol was 7%, and the yield of hexyl hexanoate was 1%.

[0105] Example 18 The same procedure as in Example 1 was carried out, except that catalyst (6) (Pt / W / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 42%, and hexyl methyl ether was produced. The yield of hexyl methyl ether was 6%.

[0106] Example 19 The same procedure as in Example 1 was carried out, except that catalyst (7) (Pt / V / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 32%, and hexyl methyl ether and 1-hexanol were produced. The yield of hexyl methyl ether was 1%, and the yield of 1-hexanol was 5%.

[0107] Example 20 The same procedure as in Example 1 was carried out, except that catalyst (8) (Ru / Re / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 44%, and hexyl methyl ether, 1-hexanol, and hexyl hexanoate were produced. The yields of hexyl methyl ether, 1-hexanol, and hexyl hexanoate were 4%, 4%, and 1%, respectively.

[0108] Example 21 The same procedure as in Example 1 was carried out, except that catalyst (9) (Ru / W / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 30%, and hexyl methyl ether was produced. The yield of hexyl methyl ether was 5%.

[0109] Example 22 The same procedure as in Example 1 was carried out, except that catalyst (10) (Ru / V / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 32%, and hexyl methyl ether and 1-hexanol were produced. The yield of hexyl methyl ether was 1%, and the yield of 1-hexanol was 5%.

[0110] Example 23 The same procedure as in Example 1 was carried out, except that catalyst (11) (Rh / Re / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 42%, and hexyl methyl ether, 1-hexanol, and hexyl hexanoate were produced. The yield of hexyl methyl ether was 1%, the yield of 1-hexanol was 3%, and the yield of hexyl hexanoate was 1%.

[0111] Example 24 The same procedure as in Example 1 was carried out, except that catalyst (12) (Rh / V / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 23%, and hexyl methyl ether was produced. The yield of hexyl methyl ether was 1%.

[0112] Example 25 The same procedure as in Example 1 was carried out, except that catalyst (13) (Pd / Mo / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 35%, and hexyl methyl ether and 1-hexanol were produced. The yield of hexyl methyl ether was 3%, and the yield of 1-hexanol was 1%.

[0113] Example 26 The same procedure as in Example 1 was carried out, except that catalyst (14) (Pd / W / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 30%, and hexyl methyl ether was produced. The yield of hexyl methyl ether was 2%.

[0114] Example 27 The same procedure as in Example 1 was carried out, except that catalyst (15) (Ir / Mo / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 43%, and hexyl methyl ether, 1-hexanol, and hexyl hexanoate were produced. The yield of hexyl methyl ether was 3%, the yield of 1-hexanol was 4%, and the yield of hexyl hexanoate was 1%.

[0115] Example 28 The same procedure as in Example 1 was carried out, except that catalyst (16) (Ir / Re / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 32%, and hexyl methyl ether, 1-hexanol, and hexyl hexanoate were produced. The yield of hexyl methyl ether was 1%, the yield of 1-hexanol was 5%, and the yield of hexyl hexanoate was 1%.

[0116] Example 29 The same procedure as in Example 1 was carried out, except that catalyst (17) (Ir / W / ZrO2) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 40%, and hexyl methyl ether was produced. The yield of hexyl methyl ether was 3%.

[0117] Example 30 The same procedure as in Example 1 was carried out, except that catalyst (18) (Pt / Mo / HAP) was used instead of catalyst (1) and the solvent was changed from diisopropyl ether to diethyl ether. As a result, the conversion rate of the substrate was 73%, and hexyl methyl ether and 1-hexanol were produced. The yield of hexyl methyl ether was 16%, and the yield of 1-hexanol was 6%.

[0118] Example 31 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal conversion) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 100°C for 4 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 97%, and cyclohexyl ethyl ether and cyclohexane were produced (see the following formula). The yield of cyclohexyl ethyl ether was 70%, and the yield of cyclohexane was 23%. Cyclohexyl alcohol was not produced.

[0119] [ka]

[0120] Example 32 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 0.25 mmol (0.036 g) of cyclohexyl acetate as a substrate, 0.0375 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal conversion) relative to the substrate], and 0.8 mL of n-hexane were charged, and the reaction was carried out at 100°C for 8 hours under a hydrogen pressure of 1 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 100%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 57%, and the yield of cyclohexane was 26%. Cyclohexyl alcohol was not produced.

[0121] Example 33 The catalyst used in Example 31 was recovered by centrifugation, dried in air at 110°C for 3 hours, and then treated in oxygen gas flow at 300°C for 20 minutes. The recovered catalyst was used to conduct an experiment under the same conditions as in Example 31. As a result, the conversion rate of the substrate was 97%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 67%, and the yield of cyclohexane was 25%. Note that cyclohexyl alcohol was not produced.

[0122] Example 34 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 21.1 mmol (3 g) of cyclohexyl acetate as a substrate, 0.45 g of catalyst (19) (Pt / Mo / ZrO2), and 30 mL of n-hexane were charged and reacted at 100°C for 112 hours under a hydrogen pressure of 50 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 88%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 58%, the yield of cyclohexyl alcohol was 6%, and the yield of cyclohexane was 21%.

[0123] Example 35 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.180 g of catalyst (20) (Pt / Mo / TiO2) [2 mol% Pt, 0.375 mol% Mo (metal conversion) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 100°C for 4 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 87%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 52%, and the yield of cyclohexane was 28%. Although cyclohexyl alcohol was produced, the yield was less than 1%.

[0124] Example 36 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.060 g of catalyst (21) (Pt / Mo / HAP) [2 mol % Pt, 0.375 mol % Mo (metal conversion) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 100°C for 4 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 30%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 19%, the yield of cyclohexyl alcohol was 1%, and the yield of cyclohexane was 10%.

[0125] Example 37 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.031 g of catalyst (22) (Pt / Mo / CeO2) [2 mol% Pt, 0.375 mol% Mo (metal conversion) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 100°C for 4 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 4%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 1%, the yield of cyclohexyl alcohol was 2%, and the yield of cyclohexane was 1%.

[0126] Example 38 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal conversion) relative to the substrate], and 3 mL of ethanol were charged, and the reaction was carried out at 100°C for 4 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 22%, and cyclohexyl ethyl ether and cyclohexyl alcohol were produced. The yield of cyclohexyl ethyl ether was 12%, and the yield of cyclohexyl alcohol was 7%. Cyclohexane was not produced.

[0127] Example 39 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal equivalent) relative to the substrate], and 3 mL of diisopropyl ether were charged and reacted at 90°C for 5 hours under a hydrogen pressure of 5 atm to obtain a reaction product. The conversion rate (conv. [%]) of the substrate and the yield (yield [%]) of each reaction product were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). The selectivity (selectivity [%]) of cyclohexyl ethyl ether was also calculated (selectivity [%] = moles of cyclohexyl ethyl ether produced / moles of cyclohexyl acetate converted × 100). As a result, the conversion of the substrate was 63%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 48% (selectivity 76%), the yield of cyclohexyl alcohol was 5%, and the yield of cyclohexane was 10%.

[0128] Example 40 The same procedure as in Example 39 was carried out, except that the reaction temperature was 100°C and the reaction time was 4 hours. As a result, the conversion rate of the substrate was 89%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 68% (selectivity 76%), the yield of cyclohexyl alcohol was 1%, and the yield of cyclohexane was 18%.

[0129] Example 41 The same procedure as in Example 39 was carried out except that the reaction temperature was 100° C. As a result, the conversion rate of the substrate was 77%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 60% (selectivity 78%), the yield of cyclohexyl alcohol was 2%, and the yield of cyclohexane was 18%.

[0130] Example 42 The same procedure as in Example 39 was carried out, except that the reaction temperature was 120°C and the reaction time was 4 hours. As a result, the conversion rate of the substrate was 99%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 66% (selectivity 67%), and the yield of cyclohexane was 29%. Note that cyclohexyl alcohol was not produced.

[0131] Example 43 The same procedure as in Example 39 was carried out, except that the reaction temperature was 100°C, the hydrogen pressure was 10 atm, and the reaction time was 4 hours. As a result, the conversion rate of the substrate was 95%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 72% (selectivity 76%), the yield of cyclohexyl alcohol was 2%, and the yield of cyclohexane was 19%.

[0132] Example 44 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal equivalent) relative to the substrate], and 3 mL of diisopropyl ether were charged and reacted at 100°C for 4 hours under a hydrogen pressure of 2 atm to obtain a reaction product. The conversion rate (conv. [%]) of the substrate and the yield (yield [%]) of each reaction product were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). The selectivity (selectivity [%]) of cyclohexyl ethyl ether was also calculated (selectivity [%] = moles of cyclohexyl ethyl ether produced / moles of cyclohexyl acetate converted × 100). As a result, the conversion of the substrate was 87%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 62% (selectivity 71%), the yield of cyclohexyl alcohol was only trace, and the yield of cyclohexane was 22%.

[0133] Example 45 The same procedure as in Example 44 was carried out, except that the hydrogen pressure was 3 atm. As a result, the conversion rate of the substrate was 94%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 66% (selectivity 70%), the yield of cyclohexyl alcohol was only a trace, and the yield of cyclohexane was 18%.

[0134] Example 46 The same procedure as in Example 44 was carried out, except that the hydrogen pressure was 3.5 atm. As a result, the conversion of the substrate was 90%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 71% (selectivity 79%), the yield of cyclohexyl alcohol was 1%, and the yield of cyclohexane was 20%.

[0135] Example 47 The same procedure as in Example 44 was carried out, except that the hydrogen pressure was 8 atm. As a result, the conversion of the substrate was 91%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 72% (selectivity 79%), the yield of cyclohexyl alcohol was 2%, and the yield of cyclohexane was 17%.

[0136] Example 48 In an autoclave equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal equivalent) relative to the substrate], and 3 mL of diisopropyl ether were charged and reacted at 100°C for 2 hours under a hydrogen pressure of 3 atm to obtain a reaction product. The conversion rate (conv. [%]) of the substrate and the yield (yield [%]) of each reaction product were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). The selectivity (selectivity [%]) of cyclohexyl ethyl ether was also calculated (selectivity [%] = moles of cyclohexyl ethyl ether produced / moles of cyclohexyl acetate converted × 100). As a result, the conversion rate of the substrate was 20%, and cyclohexyl ethyl ether and cyclohexyl alcohol were produced. The yield of cyclohexyl ethyl ether was 17% (selectivity 72%), and the yield of cyclohexyl alcohol was 5%. Cyclohexane was not produced.

[0137] Example 49 The same procedure as in Example 48 was carried out except that the reaction temperature was 120° C. As a result, the conversion rate of the substrate was 50%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 34% (selectivity 69%), the yield of cyclohexyl alcohol was 2%, and the yield of cyclohexane was 12%.

[0138] Example 50 The same procedure as in Example 48 was carried out, except that the reaction temperature was 120°C and the reaction time was 4 hours. As a result, the conversion rate of the substrate was over 99%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 66% (selectivity 66%), and the yield of cyclohexane was 33%. Note that cyclohexyl alcohol was not produced.

[0139] Example 51 The same procedure as in Example 48 was carried out except that the reaction temperature was 140° C. As a result, the conversion rate of the substrate was 45%, and cyclohexyl ethyl ether, cyclohexyl alcohol, and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 25% (selectivity 57%), the yield of cyclohexyl alcohol was only a trace amount, and the yield of cyclohexane was 13%.

[0140] Example 52 The same procedure as in Example 48 was carried out, except that the reaction temperature was 140°C and the reaction time was 4 hours. As a result, the conversion rate of the substrate was 100%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 57% (selectivity 57%), and the yield of cyclohexane was 31%. Note that cyclohexyl alcohol was not produced.

[0141] Example 53 In an autoclave (capacity 100 mL) equipped with a Teflon (registered trademark) inner cylinder, 0.5 mmol (0.071 g) of cyclohexyl acetate as a substrate, 0.075 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal equivalent) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 100°C for 8 hours under a hydrogen pressure of 1 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 99%, and cyclohexyl ethyl ether and cyclohexane were produced. The yield of cyclohexyl ethyl ether was 61%, and the yield of cyclohexane was 35%. Cyclohexyl alcohol was not produced.

[0142] Example 54 In an autoclave (capacity 100 mL) equipped with a Teflon (registered trademark) inner cylinder, 1 mmol (0.142 g) of cyclohexyl acetate as a substrate, 0.15 g of catalyst (19) (Pt / Mo / ZrO2) [2 mol% Pt, 0.375 mol% Mo (metal equivalent) relative to the substrate], and 3 mL of n-hexane were charged, and the reaction was carried out at 25°C for 168 hours under a hydrogen pressure of 50 atm to obtain a reaction product. The conversion rate of the substrate (conv. [%]) and the yield of each reaction product (yield [%]) were measured using a gas chromatograph mass spectrometer (GC-MS) (internal standard method). As a result, the conversion rate of the substrate was 10%, and cyclohexyl ethyl ether and cyclohexyl alcohol were produced. The yield of cyclohexyl ethyl ether was 2%, and the yield of cyclohexyl alcohol was 5%. Cyclohexane was not produced.

[0143] In summary, the configuration of the present disclosure and its variations are set forth below. [1] A method for producing an ether, comprising reducing a carboxylic acid ester with molecular hydrogen in the presence of the following catalyst to produce a corresponding ether in which the -C(=O)O- group of the carboxylic acid ester is converted to a -CHO- group. Catalyst: The metal species is as follows: M 1 and M. 2 A catalyst supported on the following carrier: M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite [2] The carboxylic acid ester is represented by the formula (1) (wherein R 1 represents a hydrogen atom or an organic group having a carbon atom adjacent to the carbonyl group in the formula, and R 2 represents an organic group having a carbon atom at the bonding site with the oxygen atom in the formula). [3] The catalyst contains M as a metal species. 2 , M as the metal species 1 The method for producing an ether according to the above [1] or [2], wherein the amount of the isomer is in the range of 0.05 to 1 mol per 1 mol of the isomer. [4] In the catalyst, M 1 The method for producing an ether according to any one of the above [1] to [3], wherein the amount of the supported metal (calculated as metal) is 0.01 to 10 mmol / g based on the carrier. [5] In the catalyst, M 2 The method for producing an ether according to any one of the above [1] to [4], wherein the amount of the supported metal (calculated as metal) is 0.001 to 1 mmol / g based on the carrier. [6] The specific surface area of ​​the carrier is 5 to 250 m 2 The method for producing an ether according to any one of the above [1] to [5], wherein the molar ratio is 1:1 or more. [7] The method for producing an ether according to any one of the above [1] to [6], wherein the reaction temperature of the reduction reaction is 20 to 250°C. [8] The method for producing an ether according to any one of the above [1] to [7], wherein the hydrogen pressure during the reduction reaction is 0.1 to 20 MPa. [9] The metal type is as follows: 1 and M. 21. An ester reduction catalyst comprising the following catalyst supported on a support: M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite

[10] Metal species: M 2 , M as the metal species 1 The ester reduction catalyst according to the above item [9] is contained in an amount of 0.05 to 1 mol per 1 mol of the ester.

[11] M 1 The ester reduction catalyst according to the above [9] or

[10] , wherein the amount of the supported metal (calculated as metal) is 0.01 to 10 mmol / g based on the support.

[12] M 2 The ester reduction catalyst according to any one of the above [9] to

[11] , wherein the amount of the supported metal (calculated as metal) is 0.001 to 1 mmol / g with respect to the support.

[13] The specific surface area of ​​the carrier is 5 to 250 m 2 / g. [Industrial Applicability]

[0144] According to the method for producing an ether and the ester reduction catalyst of the present disclosure, a carboxylic acid ester can be reduced with molecular hydrogen to produce the corresponding ether without discharging a large amount of salt waste or harmful waste. In addition, since the catalyst is a heterogeneous catalyst, it is easy to separate the reaction product from the catalyst. In addition, the reaction can be carried out not only in a solvent but also in a solvent-free state. Furthermore, not only symmetrical ethers but also asymmetrical ethers can be synthesized, and the range of application is wide.

Claims

1. In the presence of the following catalyst, a carboxylic acid ester is reduced with molecular hydrogen to convert the -C(=O)O- group of the carboxylic acid ester to -CH 2 A process for the preparation of ethers which produces the corresponding ethers which are converted to O-groups. Catalyst: The following metal species M 1 and M. 2 A catalyst supported on the following carrier: M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite

2. The carboxylic acid ester is represented by the following formula (1): 【Chemistry 1】 (In the formula, R 1 represents a hydrogen atom or an organic group having a carbon atom adjacent to the carbonyl group in the formula; R 2 represents an organic group having a carbon atom at the bonding site with the oxygen atom in the formula. The method for producing an ether according to claim 1, wherein the compound is represented by the formula:

3. The catalyst is a metal species M 2 M as a metal species 1 The method for producing an ether according to claim 1 or 2, wherein the content is in the range of 0.05 to 1 mol per 1 mol of the ether.

4. The metal species is as follows: 1 and M. 2 is supported on the following carrier, and a catalyst for reducing a carboxylic acid ester to convert a -C(=O)O- group of the carboxylic acid ester to -CH 2 An ester reduction catalyst used to obtain the corresponding ether converted to an O-group. M 1 : Platinum, ruthenium, rhodium, palladium or iridium M 2 : Molybdenum, rhenium, tungsten or vanadium Support: zirconium oxide, titanium oxide, cerium oxide or hydroxyapatite

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