Method of producing carboxylic acid, or salt of the same
Patent Information
- Application Number
- JP2023029622
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-02-28
- Publication Date
- 2025-12-24
Abstract
Description
[Technical field]
[0001] The present invention relates to a method for producing a carboxylic acid or a salt thereof. [Background technology]
[0002] 2. Description of the Related Art Carboxylic acids or salts thereof are widely used as raw materials or intermediates for the production of pharmaceuticals, chemical products such as polyesters, surfactants, higher alcohols, and the like.
[0003] For example, Patent Document 1 discloses a method for producing an aromatic carboxylic acid in which a carboxyl group is directly bonded to the benzene ring of the aromatic compound by reacting an aromatic compound with carbon dioxide in the presence of a specific catalyst.
[0004] Furthermore, Patent Document 2 discloses a method for producing an aromatic carboxylic acid in which a carboxyl group is directly bonded to the benzene ring of a phenol by reacting a phenol having two hydroxyl groups substituted on the benzene ring with carbon dioxide in the presence of a specific catalyst.
[0005] Furthermore, Non-Patent Document 1 discloses a method for producing a heterocyclic carboxylic acid in which a carboxyl group is directly bonded to a heterocyclic compound by reacting a heterocyclic compound with carbon dioxide in the absence of a catalyst. [Prior art documents] [Patent documents]
[0006] [Patent Document 1] Special Publication No. 2003-521480 [Patent Document 2] CN101508642 [Non-patent literature]
[0007] [Non-Patent Document 1] Nature 2016,531,215-219. Summary of the Invention [Problem to be solved by the invention]
[0008] In Patent Documents 1 and 2, methods for producing aromatic carboxylic acids using a compound having a benzene ring as a raw material are examined, but methods for producing aromatic carboxylic acids using a compound having a furan skeleton as a raw material are not examined, and further examination is required. In addition, in Non-Patent Document 1, there is still room for further examination from the viewpoints of productivity and economy in the production of heterocyclic carboxylic acids.
[0009] Therefore, an object of the present invention is to provide a method for producing a carboxylic acid or a salt thereof, which can improve the yield of the produced carboxylic acid or a salt thereof having a furan skeleton. [Means for solving the problem]
[0010] The present inventors have found that the above-mentioned problems can be solved by reacting a compound having a specific furan skeleton with carbon dioxide in the presence of a specific solid catalyst. That is, the present invention provides the following [1]. [1] A method for producing a carboxylic acid or a salt thereof, comprising reacting a compound (A) having a furan skeleton, in which carbon forming the furan skeleton is bonded to carbon or hydrogen, with carbon dioxide in the presence of a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag, to form a carboxy group. Effect of the Invention
[0011] According to the present invention, it is possible to provide a method for producing a carboxylic acid or a salt thereof, which can improve the yield of the produced carboxylic acid or a salt thereof having a furan skeleton. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The method for producing a carboxylic acid or a salt thereof of the present invention comprises reacting a compound (A) having a furan skeleton, in which carbon forming the furan skeleton is bonded to carbon or hydrogen, with carbon dioxide in the presence of a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag to form a carboxy group. In the compound (A) having a furan skeleton, the carbon forming the furan skeleton is bonded to carbon or hydrogen and is an aromatic carbon with low reactivity, and it has been difficult to form a carboxy group by reacting the compound (A) having a furan skeleton with carbon dioxide. However, according to the present invention, the compound (A) having a furan skeleton, in which the carbon forming the furan skeleton is bonded to carbon or hydrogen, is reacted with carbon dioxide to form a carboxy group, and the yield of the resulting carboxylic acid having a furan skeleton or a salt thereof can be improved. The reason for this is unclear, but is thought to be as follows. It is believed that the electron-withdrawing action of oxygen present in the furan ring of the compound (A) having a furan skeleton causes the carbon at the 5-position of the furan ring to become an electron-withdrawing group, and the nucleophilic addition reaction to carbon dioxide proceeds. It is believed that this nucleophilic addition reaction to carbon dioxide is particularly promoted by at least one metal component (x) selected from Pd and Ag. However, the reasons for the effects achieved by the present invention are not limited to these ideas.
[0013] [Compound (A) having a furan skeleton] In the method for producing a carboxylic acid or a salt thereof of the present invention, a compound (A) having a furan skeleton in which the carbon that forms the furan skeleton is bonded to carbon or hydrogen is used as a raw material. The compound (A) having a furan skeleton may be an unsubstituted furan, but from the viewpoint of the usefulness of the product, it is preferable that it has at least one substituent directly bonded to the furan skeleton, and more preferable that it has one substituent directly bonded to the furan skeleton, and from the viewpoint of improving reactivity (hereinafter also referred to as "reactivity viewpoint"), the substituent directly bonded to the furan skeleton is preferably at least one selected from a carboxy group, an alkyl group, an aldehyde group, and an ester group, and more preferably a carboxy group. However, from the viewpoint of suppressing reactions other than the intended reaction, it is preferable that the substituent directly bonded to the furan skeleton does not have a hydroxyl group, an ether group, or a halogeno group. When the compound (A) having a furan skeleton has one substituent directly bonded to the furan skeleton, the substitution position may be 2-substitution or 3-substitution, with the 2-substitution being preferred from the viewpoint of reactivity. Specifically, from the viewpoint of reactivity, the compound (A) having a furan skeleton is preferably 2-furancarboxylic acid or a salt thereof, and more preferably potassium 2-furancarboxylate.
[0014] [Solid catalyst (X)] In the method for producing a carboxylic acid or a salt thereof of the present invention, a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag is used.
[0015] The Pd contained in the metal component (x) may be Pd itself or may be derived from a compound containing Pd. The Pd-containing compound may be an oxide, hydroxide, chloride, sulfide, carbonate, sulfate, nitrate, or a complex. From the viewpoint of reactivity, Pd contained in the metal component (x) is preferably Pd itself, an oxide of Pd, or a hydroxide of Pd, more preferably Pd itself or a hydroxide of Pd.
[0016] The Ag contained in the metal component (x) may be Ag itself or may be derived from a compound containing Ag. The Ag-containing compound may be an oxide, hydroxide, chloride, sulfide, carbonate, sulfate, nitrate, or a complex. From the viewpoint of reactivity, Ag contained in the metal component (x) is preferably Ag itself or an oxide of Ag, and more preferably Ag itself.
[0017] The solid catalyst (X) is a catalyst containing at least one metal component (x) selected from Pd and Ag, and from the viewpoint of reactivity, it is preferable that the at least one metal component (x) selected from Pd and Ag is supported on a carrier.
[0018] Examples of the support for the solid catalyst (X) include activated carbon, silica, zeolite, magnesia, zirconia, ceria, alumina, titania, diatomaceous earth, and composite oxides thereof. Among these, from the viewpoint of reactivity, the support of the solid catalyst (X) is preferably at least one selected from activated carbon, silica, zeolite, magnesia, zirconia, and ceria, and more preferably at least one selected from activated carbon and silica. The shape of the carrier is not particularly limited, and is usually a powder, the median diameter (d50) of which is usually 1 to 300 μm, and may also be in other shapes derived from powder.
[0019] When the solid catalyst (X) has a support, the content of at least one metal component (x) selected from Pd and Ag contained in the solid catalyst (X) is, from the viewpoint of reactivity, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, even more preferably 1.0 mass% or more, even more preferably 5.0 mass% or more, even more preferably 8.0 mass% or more, and from the viewpoints of reactivity and economy, preferably 50 mass% or less, more preferably 30 mass% or less, even more preferably 20 mass% or less.
[0020] The solid catalyst (X) may be a supportless catalyst containing at least one metal component (x) selected from Pd and Ag. When the solid catalyst (X) does not have a support, the content of at least one metal component (x) selected from Pd and Ag contained in the solid catalyst (X) is preferably 30 mass % or more, more preferably 40 mass % or more, and even more preferably 50 mass % or more, from the viewpoint of reactivity.
[0021] The content of at least one metal component (x) selected from Pd and Ag contained in the solid catalyst (X) can be determined by ICP optical emission spectrometry (inductively coupled plasma optical emission spectrometry: ICP-AES, ICP-OES) using an ICP optical emission spectrometry analyzer (manufactured by Thermo Fisher Scientific, product name: iCAP6500Duo).
[0022] The metal component (x) contained in the solid catalyst (X) used in the present invention may contain a metal component (x') other than Pd and Ag, as long as the effect of the present invention is not impaired. Examples of the other metal component (x') include Na, K, Mg, Ca, Sc, Y, Ti, Zr, V, Nb, Mo, Mn, Fe, Ru, Co, Ni, Zn, Al, and Sn.
[0023] The content of the other metal component (x') contained in the metal component (x) may be, for example, 10 mass % or less, 5 mass % or less, 3 mass % or less, or 0 mass %. The content of the other metal component (x') contained in the metal component (x) can be determined by measuring in the same manner as for the at least one metal component (x) selected from Pd and Ag described above.
[0024] Examples of the shape of the solid catalyst (X) include powder, granules, noodles, pellets, etc. The shapes of granules, noodles, pellets, etc. can be produced by granulating and molding the powdered solid catalyst by a known method.
[0025] In a reaction system of the compound (A) having a furan skeleton and carbon dioxide, the amount of the metal component (x) contained in the solid catalyst (X) used is, from the viewpoint of the yield of the carboxylic acid having a furan skeleton or a salt thereof produced, preferably 1 part by mole or more, more preferably 3 parts by mole or more, even more preferably 5 parts by mole or more, and preferably 30 parts by mole or less, more preferably 20 parts by mole or less, even more preferably 15 parts by mole or less, and even more preferably 10 parts by mole or less, relative to 100 parts by mole of the compound (A) having a furan skeleton.
[0026] (Preparation of solid catalyst (X)) The solid catalyst (X) used in the present invention can be prepared by known methods such as coprecipitation, impregnation, and physical mixing. In the preparation process of the solid catalyst (X), known drying, calcination, and reduction treatments may be carried out as necessary.
[0027] [Additives] <Metal salt and / or base (B1) that melts at or below the reaction temperature> In the method for producing a carboxylic acid or a salt thereof of the present invention, the reaction of the compound (A) having a furan skeleton with carbon dioxide may be further carried out in the presence of a metal salt and / or a base (B1) (excluding the solid catalyst (X) and hereinafter also referred to as metal salt, etc. (B1)) that melts at a temperature equal to or lower than the reaction temperature. The term "metal salt and / or base (B1) that melts at or below the reaction temperature" refers to a metal salt that can melt and exist in a liquid state at the reaction temperature in the carboxylation reaction (preferably 150° C. or higher and 380° C. or lower) and / or a base that can melt and exist in a liquid state at the reaction temperature in the carboxylation reaction (preferably 150° C. or higher and 380° C. or lower). When multiple metal salts and / or bases (B1) are used, the mixture thereof only needs to melt at a temperature equal to or lower than the reaction temperature. By using the metal salt etc. (B1), the reaction time can be shortened and the yield of the furan skeleton-containing carboxylic acid or its salt can be improved. The reason for this is unclear, but it is thought that the metal salt etc. (B1) acts as a medium in the reaction system, thereby increasing the homogeneity of the reaction system and promoting the carboxylation reaction. Examples of the metal salt etc. (B1) include at least one selected from carboxylates, nitrates, nitrites, phosphates, sulfates, and alkoxide compounds. The metal salt etc. (B1) is preferably at least one selected from alkali metal carboxylates, alkali metal nitrates, alkali metal nitrites, and alkali metal alkoxide compounds from the viewpoint of reactivity, and more preferably an alkali metal carboxylate from the viewpoints of versatility and economy. The alkali metal carboxylate is preferably at least one selected from alkali metal formates, alkali metal acetates, and alkali metal propionates, and more preferably at least one selected from potassium formate, and a mixture of potassium acetate and sodium acetate. In a mixture of potassium acetate and sodium acetate, the molar or mass ratio of potassium acetate to sodium acetate [potassium acetate / sodium acetate] is preferably 8 / 2 to 2 / 8, more preferably 7 / 3 to 3 / 7, and even more preferably 6 / 4 to 4 / 6, from the viewpoint of solubility during the reaction.
[0028] The melting point of the metal salt etc. (B1) may be, for example, 50°C or higher, 100°C or higher, or 150°C or higher, and from the viewpoint of reactivity, is preferably 380°C or lower, more preferably 350°C or lower, even more preferably 340°C or lower, and even more preferably 330°C or lower. The melting points of the metal salts etc. (B1) are disclosed in the Chemical Handbook (compiled by the Chemical Society of Japan) and the like.
[0029] The mass ratio of the metal salt or the like (B1) to the compound (A) having a furan skeleton [(B1) / (A)] is, from the viewpoint of reactivity, preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, even more preferably 4 or more, even more preferably 5 or more, and is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, and even more preferably 8 or less.
[0030] <Base (B2) that does not melt at or below the reaction temperature> In the method for producing a carboxylic acid or a salt thereof of the present invention, the reaction of the compound (A) having a furan skeleton with carbon dioxide may be further carried out in the presence of a base (B2) (excluding the solid catalyst (X) and hereinafter also referred to as a specific base (B2)) that does not melt at a temperature equal to or lower than the reaction temperature. The "base (B2) that does not melt at or below the reaction temperature" refers to a base that can exist in a solid state without melting at the reaction temperature in the carboxylation reaction (preferably 150°C or higher and 380°C or lower). By using the specific base (B2), the reaction time can be shortened and the yield of the furan skeleton-containing carboxylic acid or its salt can be improved. The reason for this is unclear, but it is thought that the specific base (B2) has the effect of promoting a separate uncatalyzed reaction or accelerating the catalytic reaction by the solid catalyst (X). The specific base (B2) may, for example, be at least one base selected from carbonates, hydrogen carbonates, phosphates, sulfates, and hydroxides. The specific base (B2) is, from the viewpoint of reactivity, preferably at least one base selected from alkali metal carbonates, alkaline earth metal carbonates, alkali metal hydrogencarbonates, alkaline earth metal hydrogencarbonates, alkali metal phosphates, alkaline earth metal phosphates, alkali metal sulfates, alkaline earth metal sulfates, alkali metal hydroxides, and alkaline earth metal hydroxides; and, from the viewpoints of versatility and economy, more preferably at least one base selected from alkali metal carbonates and alkaline earth metal carbonates, even more preferably an alkali metal carbonate, and even more preferably at least one base selected from sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.
[0031] The mass ratio of the specific base (B2) to the compound (A) having a furan skeleton [(B2) / (A)] is, from the viewpoint of reactivity, preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.5 or more, and is preferably 10 or less, more preferably 5 or less, even more preferably 2 or less.
[0032] [Carboxylation reaction] In the method for producing a carboxylic acid or a salt thereof of the present invention, a compound (A) having a furan skeleton, in which carbon forming the furan skeleton is bonded to carbon or hydrogen, is reacted with carbon dioxide (carboxylation reaction) in the presence of a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag to form a carboxy group, thereby producing a carboxylic acid or a salt thereof.
[0033] The form of use of the solid catalyst (X) in the carboxylation reaction may be a suspension bed reaction or a fixed bed reaction, and can be appropriately selected depending on the catalytic activity, reaction scale, etc.
[0034] The reaction system of the process for producing a carboxylic acid or a salt thereof of the present invention may be any of a batch system, a semi-batch system, and a continuous system.
[0035] When the carboxylation reaction is a suspension bed reaction, a batch or semi-batch system is preferred from the viewpoint of operability, and the amount of the solid catalyst (X) used is, from the viewpoint of the yield of the produced carboxylic acid having a furan skeleton or a salt thereof, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and preferably 130 parts by mass or less, more preferably 100 parts by mass or less, even more preferably 80 parts by mass or less, relative to 100 parts by mass of the compound (A) having a furan skeleton.
[0036] The partial pressure of carbon dioxide in the carboxylation reaction is appropriately determined depending on the amount of carbon dioxide introduced into the reaction system. From the viewpoint of reactivity, the partial pressure is preferably 0.01 MPa or more, more preferably 0.1 MPa or more, and even more preferably 0.3 MPa or more, in terms of gauge pressure, and from the viewpoints of safety and economy, the partial pressure is preferably 20 MPa or less, more preferably 10 MPa or less, and even more preferably 7 MPa or less.
[0037] The reaction temperature in the carboxylation reaction is preferably 150° C. or higher, more preferably 200° C. or higher, and even more preferably 220° C. or higher, from the viewpoint of reactivity, and is preferably 380° C. or lower, more preferably 350° C. or lower, and even more preferably 300° C. or lower, from the viewpoint of selectivity.
[0038] The reaction time in the carboxylation reaction is appropriately determined depending on the type of the raw material compound (A) having a furan skeleton and the reaction temperature. In the case of a batch system, the reaction time in the carboxylation reaction is usually 1 hour or more from the viewpoint of the yield of the produced carboxylic acid having a furan skeleton or a salt thereof, and from the viewpoint of productivity, it is preferably 20 hours or less, more preferably 10 hours or less.
[0039] In the case of a continuous system, the LHSV (liquid hourly space velocity) is, from the viewpoint of the yield of the produced carboxylic acid having a furan skeleton or a salt thereof, preferably 10 / hr or less, more preferably 8 / hr or less, and even more preferably 5 / hr or less, and, from the viewpoint of productivity, is preferably 0.1 / hr or more, more preferably 0.3 / hr or more, and even more preferably 0.5 / hr or more.
[0040] In the carboxylation reaction, carbon dioxide is introduced into the reaction system. From the viewpoint of reactivity, the amount of carbon dioxide introduced is preferably 50% by volume or more, more preferably 80% by volume or more, even more preferably 90% by volume or more, and even more preferably 100% by volume, based on 100% by volume of the reaction system. The method for contacting carbon dioxide with the reaction system may involve introducing carbon dioxide into the reaction system and stirring the reaction system to increase the gas-liquid contact area, or may involve bubbling carbon dioxide into the reaction liquid.
[0041] In the carboxylation reaction, an inert gas may be introduced into the reaction system and circulated as a carrier. Examples of the inert gas include, but are not limited to, nitrogen gas and argon gas.
[0042] The carboxylic acid or a salt thereof produced by the production method of the present invention depends on the type of the raw material compound (A) having a furan skeleton. The produced carboxylic acid or a salt thereof preferably has one furan skeleton, but may have two or more rings, and preferably has two or more substituents directly bonded to the furan skeleton, is more preferably a 2,5-substituted product, and is even more preferably 2,5-furandicarboxylic acid. 2,5-Furandicarboxylic acid is useful as a raw material or intermediate for pharmaceuticals, chemical products such as polyesters, aliphatic dicarboxylic acids, aliphatic polyhydric alcohols, etc., and is particularly useful as a raw material or intermediate for polyesters or aliphatic dicarboxylic acids.
[0043] In addition to the above-mentioned embodiments, the present invention discloses the following method for producing a carboxylic acid or a salt thereof. <1> A method for producing a carboxylic acid or a salt thereof, comprising reacting a compound (A) having a furan skeleton, in which carbon forming the furan skeleton is bonded to carbon or hydrogen, with carbon dioxide in the presence of a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag, to form a carboxy group. <2> The compound (A) having a furan skeleton preferably has at least one substituent directly bonded to the furan skeleton. <1> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <3> The substituent is preferably at least one selected from a carboxy group, an alkyl group, an aldehyde group, and an ester group, and more preferably a carboxy group. <2> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <4> The compound (A) having a furan skeleton preferably does not have a hydroxyl group, an ether group, or a halogeno group as a substituent directly bonded to the furan skeleton. <1> ~ <3> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <5> The compound (A) having a furan skeleton is preferably 2-furancarboxylic acid or a salt thereof, and more preferably potassium 2-furancarboxylate. <1> ~ <4> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <6> The Pd contained in the metal component (x) is preferably Pd itself, an oxide of Pd, or a hydroxide of Pd, more preferably Pd itself or a hydroxide of Pd. <1> ~ <5> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <7> The Ag contained in the metal component (x) is preferably Ag itself or an oxide of Ag, more preferably Ag itself. <1> ~ <5> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <8> It is preferable that the metal component (x) is supported on a carrier. <1> ~ <7> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <9> The carrier is preferably at least one selected from activated carbon, silica, zeolite, magnesia, zirconia, and ceria, and more preferably at least one selected from activated carbon and silica. <8> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <10> When the solid catalyst (X) has a support, the content of at least one metal component (x) selected from Pd and Ag contained in the solid catalyst (X) is preferably 8.0 mass% or more and 30 mass% or less. <1> ~ <9> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <11> The amount of the metal component (x) contained in the solid catalyst (X) used in the reaction is preferably 5 to 20 parts by mole based on 100 parts by mole of the compound (A) having a furan skeleton. <1> ~ <10> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <12> The partial pressure of carbon dioxide in the reaction is, in terms of gauge pressure, 0.01 MPa or more and 10 MPa or less, preferably 0.01 MPa or more, more preferably 0.1 MPa or more, even more preferably 0.3 MPa or more, and preferably 20 MPa or less, more preferably 10 MPa or less, even more preferably 7 MPa or less. <1> ~ <11> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <13> The reaction temperature is 150° C. or higher and 380° C. or lower, preferably 150° C. or higher, more preferably 200° C. or higher, even more preferably 220° C. or higher, and preferably 380° C. or lower, more preferably 350° C. or lower, even more preferably 300° C. or lower. <1> ~ <12> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <14> The reaction is further carried out in the presence of a metal salt and / or a base (B1) (excluding the solid catalyst (X)) that melts at a temperature equal to or lower than the reaction temperature. <1> ~ <13> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <15> The metal salt and / or base (B1) that melts at a temperature equal to or lower than the reaction temperature is preferably at least one selected from an alkali metal carboxylate, an alkali metal nitrate, an alkali metal nitrite, and an alkali metal alkoxide compound, and more preferably an alkali metal carboxylate. <14> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <16> The alkali metal carboxylate is preferably at least one selected from alkali metal formates, alkali metal acetates, and alkali metal propionates, and more preferably at least one selected from potassium formate, and a mixture of potassium acetate and sodium acetate. <15> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <17> The melting point of the metal salt and / or base (B1) that melts at or below the reaction temperature is preferably 150° C. or higher and 330° C. or lower. <14> ~ <16> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <18> the mass ratio of the metal salt and / or base (B1) that melts at a temperature equal to or lower than the reaction temperature to the compound (A) having a furan skeleton [(B1) / (A)] is preferably 3 or more and 10 or less; <14> ~ <17> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <19> The reaction is further carried out in the presence of a base (B2) (excluding the solid catalyst (X)) that does not melt at or below the reaction temperature. <1> ~ <18> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <20> The base (B2) that does not melt at a temperature equal to or lower than the reaction temperature is preferably at least one base selected from alkali metal carbonates, alkaline earth metal carbonates, alkali metal hydrogencarbonates, alkaline earth metal hydrogencarbonates, alkali metal phosphates, alkaline earth metal phosphates, alkali metal sulfates, alkaline earth metal sulfates, alkali metal hydroxides, and alkaline earth metal hydroxides, more preferably at least one base selected from alkali metal carbonates and alkaline earth metal carbonates, even more preferably an alkali metal carbonate, and even more preferably at least one base selected from sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate. <19> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <21> The mass ratio of the base (B2) that does not melt at a temperature equal to or lower than the reaction temperature to the compound (A) having a furan skeleton [(B2) / (A)] is preferably 0.2 or more and 2 or less. <19> or <20> 3. A method for producing the carboxylic acid or a salt thereof according to claim 1 . <22> the amount of the metal component (x) contained in the solid catalyst (X) used in the reaction is 1 part by mole or more and 20 parts by mole or less relative to 100 parts by mole of the compound (A) having a furan skeleton, and is preferably 1 part by mole or more, more preferably 3 parts by mole or more, even more preferably 5 parts by mole or more relative to 100 parts by mole of the compound (A) having a furan skeleton, and is preferably 30 parts by mole or less, more preferably 20 parts by mole or less, even more preferably 15 parts by mole or less, and even more preferably 10 parts by mole or less; <1> ~ <21> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <23> When the carboxylation reaction is a suspension bed reaction, the amount of the solid catalyst (X) is preferably 20 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the compound (A) having a furan skeleton. <1> ~ <22> 3. A method for producing a carboxylic acid or a salt thereof according to any one of the preceding claims. <24> The carboxylic acid or its salt to be generated preferably has one furan ring, and is a method for producing the carboxylic acid or its salt according to any one of <1> to <23>. <25> The method for producing the carboxylic acid or its salt according to any one of <1> to <24>, wherein the carboxylic acid or its salt to be generated is 2,5-furandicarboxylic acid.
Examples
[0044] Next, the present invention will be specifically described with reference to examples, but the present invention is not limited by these examples.
[0045] <Measurement by ICP emission spectrometry> Quantification of the metal components contained in the solid catalyst was performed by ICP emission spectrometry (high-frequency inductively coupled plasma emission spectrometry: ICP-AES, ICP-OES) using an ICP emission spectrometer (manufactured by Thermo Fisher Scientific, product name: iCAP6500 Duo).
[0046] <Yield of 2,5-furandicarboxylic acid to be generated> In the examples and comparative examples, after diluting the solution after the reaction with hexane, 1 Analysis was performed under the following conditions by 1H-NMR to quantify the product. · MR-400 (400 MHz) manufactured by Agilent · Pulse Sequence: PROTON(s2pul) · Measurement conditions: waiting time → 10 seconds, number of integrations → 64 or 128 times, measurement temperature → room temperature (20 °C) · Measurement solvent: heavy water (D2O) · Attribution → Refer to literature such as Nature 2016, 531, 215-219. · Quantification method 1 Calculated from the proton ratio of 1H-NMR The yield of 2,5-furandicarboxylic acid to be generated was 1 Calculated from the results of 1H-NMR analysis using the following formulas respectively. The results are shown in Table 1, Table 2 or Table 3. Yield of 2,5-furandicarboxylic acid produced (%) = [(amount of furandicarboxylic acid produced (mol) / amount of potassium 2-furancarboxylate used as raw material (mol)] × 100
[0047] <Solid catalyst> In Examples 1 to 6 and Comparative Examples 2 to 4, the following catalysts were used, respectively. Pd / C manufactured by Tokyo Chemical Industry Co., Ltd. Ag / SiO2 Prepared using the following method Pd(OH)2 / C Fujifilm Wako Pure Chemical Corporation Ru / C Sigma-Aldrich Rh / C Fujifilm Wako Pure Chemical Corporation ·Pt / C Sigma-Aldrich
[0048] Preparation method of Ag / SiO2 Silver nitrate (3.15g, 0.0185mol, Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in water (93g) (0.2M), mixed with SiO2 (20g, Fuji Silysia Chemical Co., Ltd. CARiACT Q-10), stirred at room temperature (20℃) for 21 hours, then the water was removed and dried overnight (10 hours) at 110℃ under air. It was then ground in a coffee mill and fired in a firing furnace at 300℃ (heating 1.5h) for 4h under air (3L / min).
[0049] Example 1 A pressure-resistant vessel was charged with 40 mg of Pd / C as a solid catalyst, 56 mg of potassium 2-furancarboxylate as a compound (A) having a furan skeleton, 320 mg of potassium formate as a metal salt and / or base (B1) that melts at or below the reaction temperature, and 46 mg of potassium carbonate as a base (B2) that does not melt at or below the reaction temperature, and then carbon dioxide was sealed in so that the reaction pressure became 500 kPa. The temperature was raised to 270°C and maintained at that temperature for 5 hours to produce 2,5-furandicarboxylic acid.
[0050] (Examples 2 to 7, Comparative Examples 1 to 6) 2,5-Furandicarboxylic acid was produced in the same manner as in Example 1, except that the type and amount of the solid catalyst (X), the type of the metal salt and / or base (B1) that melts at the reaction temperature, the amount of the base (B2) that does not melt at or below the reaction temperature, and the reaction temperature were changed as shown in Table 1, Table 2, or Table 3, respectively.
[0051] [Table 1]
[0052] By comparing Examples 1 and 2 with Comparative Examples 1 to 4, it was confirmed that the yield of the produced furan skeleton-containing carboxylic acid or a salt thereof could be improved.
[0053] [Table 2]
[0054] Comparing Examples 3 to 5 with Comparative Example 5, it was confirmed that the yield of the produced furan skeleton-containing carboxylic acid or a salt thereof could be improved.
[0055] [Table 3]
[0056] Comparing Examples 6 to 7 with Comparative Example 6, it was confirmed that the yield of the produced furan skeleton-containing carboxylic acid or a salt thereof could be improved.
Claims
1. A method for producing a carboxylic acid or a salt thereof, comprising reacting a compound (A) having a furan skeleton, in which carbon atoms forming the furan skeleton are bonded to carbon or hydrogen, with carbon dioxide in the presence of a solid catalyst (X) containing at least one metal component (x) selected from Pd and Ag, to form a carboxy group.
2. 2. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the compound (A) having a furan skeleton has at least one group selected from a carboxy group, an alkyl group, an aldehyde group, and an ester group directly bonded to the furan skeleton.
3. 2. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the compound (A) having a furan skeleton is 2-furancarboxylic acid or a salt thereof.
4. 2. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the partial pressure of carbon dioxide in the reaction is from 0.01 MPa to 10 MPa in terms of gauge pressure.
5. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the reaction temperature is 150°C or higher and 380°C or lower.
6. 2. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the reaction is further carried out in the presence of a metal salt and / or a base (B1) (excluding the solid catalyst (X)) that melts at a temperature equal to or lower than the reaction temperature.
7. The method for producing a carboxylic acid or a salt thereof according to claim 1, wherein the reaction is further carried out in the presence of a base (B2) (excluding the solid catalyst (X)) that does not melt at a temperature equal to or lower than the reaction temperature.
8. The method for producing a carboxylic acid or a salt thereof according to claim 1 , wherein the metal component (x) contained in the solid catalyst (X) is supported on a carrier.
9. The method for producing a carboxylic acid or a salt thereof according to claim 8, wherein the carrier is at least one selected from activated carbon and silica.
10. The method for producing a carboxylic acid or a salt thereof according to any one of claims 1 to 9, wherein the amount of the metal component (x) contained in the solid catalyst (X) used in the reaction is 1 part by mole or more and 20 parts by mole or less per 100 parts by mole of the compound (A) having a furan skeleton.