Process for producing 2-furanecarbonitrile and process for producing carbonate

Abstract

According to the present application, a method for producing 2-furan carbonitrile by dehydrating 2-furan carboxamide in the presence of a Mo / SiO2 catalyst obtained by supporting molybdenum (Mo) on a support composed of SiO2 can be provided. The present application is preferably a method in which the above dehydration is performed in the presence of a drying agent such as a molecular sieve.

Description

Technical Field

[0001] The present invention relates to a method for producing 2-furancarbonitrile and a method for producing carbonate. Background Art

[0002] Carbonate is a general term for compounds in which one or two of the two hydrogen atoms of carbonic acid CO(OH)2 are replaced by an alkyl group or an aryl group, and is a compound having a structure of RO-C(=O)-OR' (R, R' represents a saturated hydrocarbon group or an unsaturated hydrocarbon group).

[0003] Carbonates are very useful compounds, not only as additives for increasing octane ratings in gasoline and reducing particulate matter in exhaust gases, but also as alkylating agents, carbonylating agents, and solvents in the synthesis of resins and organic compounds such as polycarbonates and polyurethanes, pharmaceuticals, and pesticides, as well as raw materials for lithium-ion battery electrolytes, lubricating oils, and rust-proofing agents for boiler pipes.

[0004] The mainstream method for producing carbonate esters is a method that uses phosgene as a carbonyl source and reacts it directly with alcohol. Because this method uses extremely harmful and highly corrosive phosgene, careful attention is required during its transportation and storage, resulting in high costs for maintaining and managing the manufacturing equipment and ensuring safety. Furthermore, when this method is used for production, the raw materials and catalysts contain halogens such as chlorine, and the resulting carbonate ester contains trace amounts of halogen that cannot be removed through simple refining processes. In applications such as gasoline additives, light oil additives, and electronic materials, there is a risk of corrosion, thus requiring a thorough refining process to convert the trace halogens present in the carbonate ester into extremely small amounts. Furthermore, because phosgene, which is extremely harmful to the human body, is used, increasingly stringent administrative regulations prohibit the installation of additional manufacturing equipment using this method, creating a strong demand for new methods for producing carbonate esters that do not use phosgene.

[0005] For this reason, the method for the direct synthesis of carbonate by alcohol and carbonic acid gas using heterogeneous catalysts is known.In this method, following research has been carried out: in order to improve the output of carbonate, by using 2-cyanopyridine or benzonitrile as hydrating agent, significantly improve the output and the generation rate of carbonate, make reaction be easy to carry out under the pressure close to normal pressure, and accelerate reaction speed (with reference to patent documentation 1,2).But, about the processing method of by-product benzamide etc. and utilization method still have the need to improve part.

[0006] For example, the use of benzamide, produced by the reaction of benzonitrile with water, is limited to a few pharmaceutical and pesticide intermediates. Consequently, there is a need to regenerate benzamide, a byproduct generated during carbonate production where benzonitrile is used as a hydrating agent, into benzonitrile for reuse. The challenge is to perform this regeneration reaction with high selectivity (given that the byproduct is difficult to reuse as a hydrating agent) and high yield (given that low yields increase the amount of residual benzamide, which increases the separation process load from benzonitrile and adds to the load).

[0007] Taking into account the need for improvement in the regeneration of benzamide to benzonitrile, etc., there is known a method that enables the regeneration without using a strong reagent and while suppressing the formation of by-products (Patent Document 3).

[0008] However, this method has the following aspects that need improvement: since the dehydration of the amide compound to generate the nitrile (regeneration) requires 400 hours, it cannot be balanced with the synthesis reaction of the carbonate ester that completes the reaction within 24 hours, that is, they cannot be used together, and in order to separate the catalyst from the solid and liquid, operations such as extraction and filtration are required, resulting in a long and complicated process.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-77113

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-162523

[0013] Patent Document 3: WO2015 / 099053 Summary of the Invention

[0014] Technical problem to be solved by the invention

[0015] In view of the above-mentioned problems in the prior art, the technical problem to be solved by the present invention is to provide a dehydration reaction method that can suppress the production of by-products and selectively obtain the target compound with high yield during the regeneration of nitrile by dehydration of amide compounds.

[0016] The technical problem of the present invention is also to apply the above-mentioned method for producing (regenerating) nitrile compounds to a method for producing carbonate esters, thereby realizing an efficient method for producing carbonate esters.

[0017] Technical solutions to technical problems

[0018] In order to solve the above technical problems, the present inventors have conducted in-depth research on the method for producing a nitrile compound by dehydrating an amide compound. As a result, it was found that by dehydrating 2-furancarbonamide in the presence of a specific catalyst, the production of by-products can be suppressed, and 2-furancarbonitrile as the target compound can be selectively obtained in high yield.

[0019] Thus, can utilize amide compound to the regeneration rate of the dehydration reaction of nitrile compound and have used nitrile compound by CO Between the building-up rate of the carbonate ester that alcohol carries out, obtain balance, that is, can be set up as a series of commercial process with the building-up reactions of dehydration reaction and carbonate ester.Therefore, the present inventor has also studied the manufacture method that above-mentioned insight is applied to carbonate ester.

[0020] That is, the present invention is as follows.

[0021] <1> A method for producing 2-furancarbonitrile, wherein 2-furancarbonamide is dehydrated in the presence of a Mo / SiO2 catalyst obtained by supporting molybdenum (Mo) on a carrier composed of SiO2 to produce 2-furancarbonitrile.

[0022]

[0023] <2> As mentioned above <1> The method for producing 2-furancarbonitrile, wherein the dehydration is carried out in the presence of a desiccant.

[0024] <3> As mentioned above <2> The method for producing 2-furancarbonitrile, wherein the desiccant is a molecular sieve.

[0025] <4> As mentioned above <1> ~ <3> The method for producing 2-furancarbonitrile according to any one of the preceding claims, wherein 2-furancarboxylic acid is produced simultaneously with the production of the 2-furancarbonitrile.

[0026]

[0027] <5> A method for producing a carbonate ester, comprising:

[0028] The first reaction step comprises: a carbonate formation reaction in which an alcohol is reacted with carbon dioxide in the presence of a solid catalyst, 2-furancarbonitrile and a solvent to generate carbonate and water; and a hydration reaction in which the generated water is hydrated with the 2-furancarbonitrile to generate 2-furancarboxamide; and

[0029] The second reaction step comprises separating the 2-furancarboxamide from the reaction system of the first reaction step, and then dehydrating the 2-furancarboxamide in the presence of a Mo / SiO catalyst in which molybdenum (Mo) is supported on a SiO support to regenerate the 2-furancarboxamide into 2-furancarbonitrile.

[0030] At least a portion of the 2-furancarbonitrile regenerated in the second reaction step is used in the first reaction step.

[0031] <6> As mentioned above <5> The method for producing carbonate esters, wherein the dehydration is carried out in the presence of a desiccant.

[0032] <7> As mentioned above <6> In the method for producing carbonate, the desiccant is a molecular sieve.

[0033] <8> As mentioned above <5> ~ <7> The method for producing a carbonate ester according to any one of the preceding claims, wherein the alcohol comprises an alcohol having 1 to 6 carbon atoms.

[0034] <9> As mentioned above <5> ~ <8> The method for producing a carbonate ester according to any one of the preceding claims, wherein the solid catalyst comprises at least one of CeO 2 and ZrO 2 .

[0035] <10> As mentioned above <5> ~ <9> The method for producing a carbonate ester according to any one of the preceding claims, wherein a solvent having a boiling point higher than that of the 2-furancarboxamide to be produced is used in the first reaction step.

[0036] <11> As mentioned above <10> In the method for producing carbonate ester, the solvent comprises at least one of dialkylbenzene, alkylnaphthalene and diphenylbenzene.

[0037] Effects of the Invention

[0038] As mentioned above, according to the present invention, can carry out efficiently the manufacturing (regeneration) from amide compounds to nitrile compounds.That is, in the dehydration reaction of the amide compounds for above-mentioned regeneration, can suppress the generation of by product, obtain target compound with high yield selectivity.Therefore, according to the present invention, the reaction times of the dehydration reaction that nitrile compounds is regenerated can be significantly shortened compared with prior art.

[0039] Furthermore, according to the present invention, by producing a nitrile compound as described above, an efficient method for producing a carbonate ester can also be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram showing a reactor (furnace) used in Examples and Comparative Examples. DETAILED DESCRIPTION

[0041] Preferred embodiments of the present invention are described in detail below.

[0042] <Method for producing 2-furanonitrile>

[0043] A method for producing 2-furancarbonitrile according to one embodiment of the present invention is a method for producing 2-furancarbonitrile by dehydrating 2-furancarboxamide in the presence of a Mo / SiO2 catalyst obtained by supporting molybdenum (Mo) on a carrier composed of SiO2.

[0044]

[0045] Regarding the method for producing the catalyst used in the above-mentioned dehydration reaction of the present invention, the following example is given. As a carrier, commercially available powdered or spherical SiO2 can be used. It is granulated to a size of 100 mesh (0.15 mm) or less in a manner that can evenly support molybdenum (Mo) as an active metal. In order to remove moisture, it is preferably pre-fired in air at a temperature of 700°C for 1 hour. In addition, although SiO2 also has products with various properties, products with large surface areas are preferred because the larger the surface area, the higher the dispersibility of molybdenum (Mo), and the more it can increase the yield of 2-furancarbonitrile. Specifically, 300m 2 / g or more. However, the surface area of ​​the prepared catalyst may sometimes be lower than the surface area of ​​SiO2 alone due to the interaction between SiO2 and molybdenum (Mo). In this case, the surface area of ​​the prepared catalyst is preferably 150m 2 Molybdenum (Mo) as an active species can be supported by an impregnation method such as an incipient wetness method or an evaporation drying method.

[0046] The metal salt used as the catalyst precursor can be any water-soluble compound, and various compounds can be used. A carrier can be impregnated with an aqueous solution of an alkaline metal precursor, which can then be dried and calcined to form a catalyst. The calcination temperature depends on the precursor used, but is preferably 400-600°C.

[0047] The catalyst loading can be appropriately set. For example, the metal-equivalent loading of molybdenum (Mo) oxide based on the total weight of the catalyst is preferably set to approximately 0.1 to 1.5 mmol / g, particularly preferably to approximately 0.1 to 1 mmol / g. If the loading exceeds this value, activity may decrease.

[0048] The amount of the catalyst used during the reaction can be appropriately set, and is preferably 20 to 150 parts by mass, more preferably 30 to 130 parts by mass, relative to 100 parts by mass of 2-furancarboxamide.

[0049] The catalyst used in the present invention is preferably a catalyst obtained by supporting only molybdenum (Mo) oxide on a carrier composed of SiO2, but may contain unavoidable impurities other than the above elements that are mixed in during the catalyst production process, etc. However, it is preferred that impurities be kept as little as possible.

[0050] The catalyst used in the present invention, which is obtained by supporting molybdenum (Mo) oxide, which will become an active species, on a carrier, can be in any form of powder or a molded body. In the case of a molded body, it can be in any shape such as sphere, pellet, cylinder, ring, wheel, or granular.

[0051] In the manufacture method of the 2-furancarbonitrile of the present invention that has used catalyzer, reaction form is not particularly limited, and any kind in the flow-through reactor such as batch reactor, semi-batch reactor, continuous tank reactor, tubular reactor can be used.In addition, catalyzer can be applicable to any kind in fixed bed, slurry bed etc.

[0052] The general reaction conditions in the method for producing 2-furancarbonitrile of the present invention are, but not particularly limited to, a reaction liquid temperature of 160 to 230° C., a pressure of normal pressure (101.3 (kPa) (760 Torr)) to reduced pressure (1.33 (kPa) (10 Torr)), and a time of several hours to about 100 hours.

[0053] For example, the reaction solution temperature is preferably 170 to 220°C, more preferably 180 to 210°C. Furthermore, the reaction time is preferably 6 to 90 hours, more preferably 10 to 80 hours, and particularly preferably 20 to 75 hours. Regarding the pressure, atmospheric pressure is preferred from the perspective of not requiring a pressure reducing device and from the perspective of energy efficiency.

[0054] The method for producing 2-furancarbonitrile of the present invention preferably comprises dehydrating 2-furancarboxamide in the presence of a desiccant in addition to a Mo / SiO2 catalyst. The type of desiccant is not particularly limited, but a molecular sieve is preferably used.

[0055] When using molecular sieves as dehydrating agents, there are no particular restrictions on their type or shape. For example, 3A, 4A, and 5A, which are generally highly absorbent and in spherical or pelletized forms, can be used. For example, Tosoh's Zeoram is suitable. It is also preferable to pre-dry the sieves, preferably at 300-500°C for approximately one hour.

[0056]

[0057] In the present invention, during the dehydration reaction of 2-furancarboxamide, 2-furancarboxylic acid as a byproduct may be produced due to the decomposition of 2-furancarboxamide. However, the reaction solution after the dehydration reaction using the reaction conditions of the present invention contains a large amount of unreacted 2-furancarboxamide and the product 2-furancarbonitrile, and the byproduct represented by the above formula is not produced much.

[0058] <Method for producing carbonate ester using 2-furanonitrile>

[0059] As mentioned above, in the regeneration of the dehydration reaction of utilizing from 2-furancarboxamide to 2-furancarbonitrile, can, when not using potent reagent, suppress the generation of by product, and obtain target compound with high yield selectivity.Thus, can utilize 2-furancarboxamide to the regeneration rate of the dehydration reaction of 2-furancarbonitrile and have used 2-furancarbonitrile by CO 2 and between the synthesis rate of the carbonate that alcohol carries out, obtain balance, that is, can use, these reactions can be established as a series of commercial processes.Thus, the inventor applies above-mentioned insight to the manufacture method of carbonate, thereby can expect the manufacture method of following carbonate.

[0060] (First Reaction Step)

[0061] The first reaction step in the method for producing carbonate esters of the present invention includes a reaction (carbonate ester production reaction) in which an alcohol is directly reacted with carbon dioxide in the presence of a solid catalyst such as CeO2, 2-furanonitrile and a solvent to produce carbonate esters.

[0062] In this operation, although when making alcohol and carbonic acid gas reaction, except carbonate, also can generate water, owing to the existence of 2-furancarbonitrile, therefore by the hydration reaction with the water that generates, can generate 2-furancarboxamide.And, by from reaction system, removing or reducing the water that generates, can promote the generation of carbonate.For example, as shown in following formula.

[0063]

[0064] (alcohol)

[0065] As alcohol, one or more arbitrary alcohols selected from primary alcohols, secondary alcohols and tertiary alcohols can be used. For example, when using methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, allyl alcohol, 2-methyl-1-propanol, cyclohexanemethanol, benzyl alcohol, ethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol, because the yield of product is high and the reaction speed is also fast, it is preferred. At this time, the carbonate to be generated is respectively dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, diallyl carbonate, di(2-methylpropyl) carbonate, dicyclohexane methyl carbonate, dibenzyl carbonate, ethylene carbonate, 1,2-propylene carbonate and 1,3-propylene carbonate.

[0066] When the obtained carbonate is used as a raw material for diaryl carbonate, as the alcohol, an alcohol having 1 to 6 carbon atoms is preferably used, and an alcohol having 2 to 4 carbon atoms is more preferably used.

[0067] Furthermore, monohydric alcohols or dihydric alcohols are preferably used.

[0068] (Carbonate production catalyst)

[0069] In the first reaction step for producing carbonate esters, a solid catalyst of either or both CeO2 and ZrO2 is preferably used. For example, CeO2 alone, ZrO2 alone, a mixture of CeO2 and ZrO2, or a solid solution or composite oxide of CeO2 and ZrO2 is preferred, with CeO2 alone being particularly preferred. Furthermore, the solid solution or composite oxide of CeO2 and ZrO2 is generally prepared with a CeO2:ZrO2 mixing ratio of 50:50, but the mixing ratio can be appropriately varied.

[0070] The solid catalyst used in the first reaction step may be in the form of a powder or a molded body. In the case of a molded body, the solid catalyst may be in any shape such as a sphere, a pellet, a cylinder, a ring, a wheel, or a granule.

[0071] (carbon dioxide)

[0072] The carbon dioxide used in the present invention may be not only carbon dioxide produced as industrial gas but also carbon dioxide separated and recovered from exhaust gas of factories that manufacture various products, steel mills, power plants, and the like.

[0073] (Solvent in Carbonate Formation Reaction)

[0074] In the carbonate formation reaction, preferably use a solvent having a boiling point higher than the 2-furancarboxamide to be generated. More preferably: the solvent in the carbonate formation reaction comprises at least one of dialkylbenzene, alkylnaphthalene and diphenylbenzene. As a specific example, BARRELPROCESS oil B28AN and BARRELPROCESS oil B30 (Matsumura Oil System) etc., which comprise components such as dialkylbenzene, alkylnaphthalene and diphenylbenzene, can be enumerated.

[0075] (Reaction liquid temperature)

[0076] As the reaction liquid temperature in the carbonate formation reaction, it is preferably set to 50~300 ℃. When the reaction liquid temperature is lower than 50 ℃, the reaction speed is low, and there is the following tendency, that is, the carbonate synthesis reaction and the hydration reaction utilizing 2-furancarbonitrile almost do not progress, and the productivity of carbonate is low. In addition, when the reaction liquid temperature exceeds 300 ℃, although the reaction speed of each reaction is improved, there is the following tendency, that is, carbonate is easy to decompose and modify, and 2-furancarbonamide is easy to react with alcohol, so the yield of carbonate is reduced. More preferably, it is 100~150 ℃. However, considering that this temperature varies depending on the type and amount of the solid catalyst, the amount and ratio of the raw materials (alcohol, 2-furancarbonitrile), etc., it is necessary to appropriately set the optimal conditions. Since the preferred reaction liquid temperature is 100~150 ℃, it is preferred to preheat the raw materials (alcohol, 2-furancarbonitrile) with steam or the like in the front section of the carbonate reactor.

[0077] (Reaction pressure)

[0078] As the reaction pressure in the carbonate formation reaction, preferably be set to 0.1~20MPa (absolute pressure).When reaction pressure is lower than 0.1MPa (absolute pressure), need pressure reducer, not only equipment complexity and cost improve, and also need to be used for the kinetic energy of decompression, cause energy efficiency variation.In addition, when reaction pressure surpasses 20MPa, utilize the hydration reaction of 2-furancarbonitrile to be difficult to carry out, not only make the yield variation of carbonate, and need the required kinetic energy of boosting, cause energy efficiency variation.In addition, consider from the viewpoint of the yield that improves carbonate, reaction pressure is more preferably 0.5~15MPa (absolute pressure), further be preferably 1.0~10MPa (absolute pressure).

[0079] (Amount of 2-furanonitrile)

[0080] The 2-furancarbonitrile used in the hydration reaction is preferably according to feed alcohol and CO The molar amount of the theoretical molar amount of the by-product water generated by reaction is more than 0.2 times and less than 5 times, and is imported into the reactor in advance before the reaction. More preferably, the molar amount of 2-furancarbonitrile is feed alcohol and CO The theoretical molar amount of the by-product water generated by reaction is more than 0.5 times and less than 3 times, and particularly preferably more than 0.8 times and less than 1.5 times. When the molar amount of 2-furancarbonitrile is too little, the 2-furancarbonitrile that contributes to the hydration reaction is few, so the yield variation of carbonate is likely to be made. On the other hand, when having imported the 2-furancarbonitrile that is excessive in molar amount compared with feed alcohol, because the side reaction of 2-furancarbonitrile increases, it is not preferred. In addition, considering that alcohol and 2-furancarbonitrile are different with respect to the consumption of solid catalyst because of the kind and consumption of solid catalyst, the kind of alcohol and the ratio of 2-furancarbonitrile etc., therefore need suitably be set to optimal condition.

[0081] (Distillation Separation)

[0082] After the reaction, the carbonate as the main product, 2-furancarbonamide as the by-product, unreacted 2-furancarbonitrile, CeO2 and other solid catalysts are separated by distillation to recover the products.

[0083] (Second Reaction Step)

[0084] Next, in the second reaction step of the present invention, the by-product 2-furancarbonamide in the first reaction step is separated from the system after the carbonate formation reaction, and then subjected to a dehydration reaction to produce 2-furancarbonitrile. Since the second reaction step corresponds to the above-mentioned method for producing 2-furancarbonitrile, its detailed description is omitted.

[0085] (Recycling of 2-furanonitrile)

[0086] The 2-furanonitrile regenerated in the second reaction step can be reused in the first reaction step (hydration reaction).

[0087] Example

[0088] The present invention is described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0089] <Gas Chromatography (GC) Analysis of Reaction Products>

[0090] The obtained reaction product was dissolved in 20 g of acetone, filtered, placed in a GC analysis bottle, and subjected to GC analysis.

[0091] (GC and measurement conditions)

[0092] GC column: CP-Sil 5CB manufactured by Agilent Technology Co., Ltd. (length 50 m, film thickness 0.25 μm, inner diameter 0.25 mm)

[0093] Inlet pressure: 100kPa

[0094] Vaporization chamber temperature: 320℃

[0095] Column flow rate: 0.83 mL / min

[0096] Linear speed: 19.9cm / s

[0097] Split ratio: 25.0

[0098] Total flow rate: 24.5 mL / min

[0099] Carrier gas: N2

[0100] Detector: Flame ionization detector (FID)

[0101] Detector temperature: 320°C

[0102] Internal standard substance: Dodecane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., purity 97%)

[0103] Column temperature program:

[0104] (Initial) temperature 50°C, holding time 0 minutes

[0105] (Level 1) Heating rate 30℃ / min, reaching temperature 130℃, holding time 0 minutes,

[0106] (Level 2) Heating rate 5℃ / min, reaching temperature 180℃, holding time 0 minutes,

[0107] (Level 3) Heating rate: 30°C / min, reaching temperature: 300°C, holding time: 10 minutes.

[0108] (Preparation Example 1 of Supported Catalyst)

[0109] The supported catalyst was prepared according to the following steps based on the incipient wetness impregnation method.

[0110] In a 5 mL bottle, accurately weigh (NH4)6Mo7O 24 0.089 g of 4H2O (measured as MoO3 81%, manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent, distributor 010-06905, lot number PTN1484) was diluted with 3 mL of distilled water to prepare a catalyst precursor solution.

[0111] While heating and stirring, the catalyst precursor solution was gradually added dropwise to a 100 mL beaker containing 0.96 g of SiO2. The water was then evaporated on a hot stirrer and then dried in an oven at 110°C for 12 hours. The resulting catalyst was placed in a muffle furnace and heated to 500°C at a rate of 10°C / min. It was then calcined at 500°C for 3 hours to obtain a Mo / SiO2 supported catalyst with a Mo loading of 0.5 mmol / g.

[0112] (Preparation Example 2 of Supported Catalyst)

[0113] 0.081 g of cesium carbonate (anhydrous) (specification content: 95.0-102.0% (titration), Fujifilm Wako Pure Chemical Industries, Ltd., Wako Grade 1, distributor 034-06542, lot number CAG5233) was used instead of (NH4)6Mo7O 24 ·4H2O, except for this, the same method as Preparation Example 1 was carried out to obtain a Cs / SiO2 supported catalyst with a Cs loading of 0.5 mmol / g.

[0114] <Example 1>

[0115] (Dehydration reaction of 2-furancarboxamide)

[0116] In a reaction tube equipped with a stirrer, 340 mg (3 mmol) of 2-furancarboxamide (manufactured by AK Scientific, Inc., purity 98.0%) as a raw material, 400 mg of the Mo / SiO2 supported catalyst obtained in Preparation Example 1, 0.1 g of dodecane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an internal standard substance, 20 g of mesitylene as a solvent, mesh, wool, and 2 g of molecular sieve 3A previously calcined at 300°C for 1 hour as a desiccant were added in sequence, and the mixture was placed in a jar. Figure 1 The reactor (furnace) shown in FIG. 1 is provided with a cooling pipe on the upper portion of the connecting portion, and a balloon is further provided on the upper portion of the cooling pipe.

[0117] The reactor (furnace) was set at 180°C and 600 rpm. The reaction was started at the time when boiling of the reaction solution was confirmed, and the reaction was continued for 72 hours. The reaction was stopped at the time when the solution was removed from the reactor. The reaction product was cooled to obtain a yield of 91% for 2-furanonitrile.

[0118] The yield (%) of 2-furancarbonamide to 2-furancarbonitrile was calculated by the following formula.

[0119] Yield of 2-furancarbonitrile [%] = yield of 2-furancarbonitrile [mmol] / amount of raw material 2-furancarbonamide [mmol] × 100

[0120] <Example 2>

[0121] A reaction product was obtained in the same manner as in Example 1 except that 680 mg (6.0 mmol) of 2-furancarbonamide (manufactured by AK Scientific, Inc., purity 98.0%) was used as a raw material. The yield of the obtained 2-furancarbonitrile was 88%.

[0122] <Example 3>

[0123] A reaction product was obtained in the same manner as in Example 1, except that no desiccant (molecular sieve) was used. The yield of the obtained 2-furancarbonitrile was 86%.

[0124] <Example 4>

[0125] A reaction product was obtained in the same manner as in Example 1 except that the amount of catalyst added was changed from 400 mg to 100 mg and the reaction time was changed from 72 hours to 24 hours. The yield of the obtained 2-furancarbonitrile was 57%.

[0126] <Example 5>

[0127] A reaction product was obtained in the same manner as in Example 4 except that no desiccant (molecular sieve) was used. The yield of the obtained 2-furancarbonitrile was 53%.

[0128] <Example 6>

[0129] A reaction product was obtained in the same manner as in Example 1, except that the reaction time was changed from 72 hours to 6 hours. The yield of the obtained 2-furancarbonitrile was 25%.

[0130] <Example 7>

[0131] A reaction product was obtained in the same manner as in Example 6, except that no desiccant (molecular sieve) was used. The yield of the obtained 2-furancarbonitrile was 17%.

[0132] <Comparative Example 1>

[0133] A reaction product was obtained in the same manner as in Example 4 except that the Cs / SiO2 supported catalyst obtained in Preparation Example 2 was used as the catalyst. The yield of the obtained 2-furancarbonitrile was 38%.

[0134] <Comparative Example 2>

[0135] A reaction product was obtained in the same manner as in Example 5, except that the Cs / SiO2 supported catalyst obtained in Preparation Example 2 was used as the catalyst. The yield of the obtained 2-furancarbonitrile was 27%.

[0136] <Comparative Example 3>

[0137] A reaction product was obtained in the same manner as in Example 6, except that the Cs / SiO2 supported catalyst obtained in Preparation Example 2 was used as the catalyst. The yield of the obtained 2-furancarbonitrile was 14%.

[0138] <Comparative Example 4>

[0139] A reaction product was obtained in the same manner as in Example 7 except that the Cs / SiO2 supported catalyst obtained in Preparation Example 2 was used as the catalyst. The yield of the obtained 2-furancarbonitrile was 16%.

[0140] [Table 1]

[0141]

[0142] <Example 8>

[0143] Cerium oxide (HSA-20SP manufactured by Solvay Special Chem Japan Co., Ltd., average particle size of about 10 μm, impurity concentration of 0.02% or less) was calcined at 600° C. in an air atmosphere for 3 hours to obtain a powdery solid catalyst.

[0144] Next, 0.344 g (20 mmol) of the above-mentioned solid catalyst, 2.33 g (25.0 mmol) of 2-furancarbonitrile obtained in Example 1 and 0.751 g (12.5 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) of 1-propanol were added to an autoclave (with two inclined paddle stirring blades, made of SUS316, with a capacity of 190 mL). After replacement with CO2, the system was filled with CO2, pressurized to 5 MPa, and the reaction was carried out at a reaction temperature of 132°C for 4 hours (i.e., the formation reaction of aliphatic carbonate).

[0145] The autoclave was then cooled and the pressure removed, and the reaction solution was recovered. Gas chromatography analysis of the reaction solution revealed 7.31 g (5.0 mmol) of the target product, dipropyl carbonate (DPrC), 0.67 g (6.0 mmol) of 2-furancarboxamide as a by-product, 0.0412 g (0.04 mmol) of propyl carbamate, 0.0154 g (0.10 mmol) of furan-2-carboxylic acid propyl ester, and 0.0153 g (0.10 mmol) of furan-2-imidic acid propyl ester.

[0146] Next, after separating the 2-furancarboxamide obtained as a by-product, the same operation as in Example 1 was repeated using this 2-furancarboxamide to regenerate 2-furancarbonitrile. The regenerated 2-furancarbonitrile was then reused in the above-mentioned aliphatic carbonate production reaction.

Claims

1. A method for producing 2-furancarbonitrile, characterized in that: In the presence of a Mo / SiO2 catalyst in which molybdenum (Mo) is supported on a carrier composed of SiO2, 2-furancarbonamide is dehydrated to produce 2-furancarbonitrile.

2. The method for producing 2-furancarbonitrile according to claim 1, wherein: The dehydration is carried out in the presence of a desiccant as well.

3. The method for producing 2-furancarbonitrile according to claim 2, wherein: The desiccant is a molecular sieve.

4. The method for producing 2-furanonitrile according to any one of claims 1 to 3, wherein: While generating the 2-furancarbonitrile, 2-furancarboxylic acid is generated.

5. A method for producing a carbonate ester, characterized in that: include: The first reaction step comprises: reacting an alcohol with carbon dioxide in the presence of a solid catalyst, 2-furancarbonitrile and a solvent to produce a carbonate and water; and hydrating the generated water with the 2-furancarbonitrile to generate 2-furancarbonamide; and A second reaction step comprises separating the 2-furancarboxamide from the reaction system of the first reaction step, and then dehydrating the 2-furancarboxamide in the presence of a Mo / SiO catalyst in which molybdenum (Mo) is supported on a SiO support to regenerate the 2-furancarboxamide into 2-furancarbonitrile. At least a portion of the 2-furancarbonitrile regenerated in the second reaction step is used in the first reaction step.

6. The method for producing a carbonate according to claim 5, wherein: The dehydration is carried out in the presence of a desiccant as well.

7. The method for producing a carbonate according to claim 6, wherein: The desiccant is a molecular sieve.

8. The method for producing a carbonate according to any one of claims 5 to 7, wherein: The alcohol includes alcohols having 1 to 6 carbon atoms.

9. The method for producing a carbonate according to any one of claims 5 to 7, wherein: The solid catalyst comprises at least one of CeO2 and ZrO2.

10. The method for producing a carbonate according to any one of claims 5 to 7, wherein: In the first reaction step, a solvent having a boiling point higher than that of the 2-furancarboxamide to be produced is used.

11. The method for producing a carbonate according to claim 10, wherein: The solvent comprises at least one of dialkylbenzene, alkylnaphthalene and diphenylbenzene.

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