Method for producing ester compounds, method for producing 2-pyrrolidone, and method for producing N-methyl-2-pyrrolidone

Abstract

To provide a manufacturing method of an ester compound that causes a carbonylation reaction of α,β-unsaturated nitrile, alcohol and carbon mono-oxide at a low reaction pressure, so as to enable an ester compound to be manufactured.SOLUTION: An manufacturing method of an ester compound causes a carbonylation reaction of α,β-unsaturated nitrile, alcohol and carbon mono-oxide in a presence of a catalyst to manufacture a prescribed ester compound. A catalyst thereof includes: a compound having at least one element selected from elements of group 9 and group 10 of the periodic table; and a bidentate phosphine ligand. The bidentate phosphine ligand is at least one kind selected from a group consisting 4,5-bis(diphenylphosphino)-9,9-dimethyl xanthene, 1,1'-bis(di-iso-propyl phosphino) ferrocene and 1,2-bis(di-tert-butyl phosphino methyl) benzene.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing an ester compound, a method for producing 2-pyrrolidone using the same, and a method for producing N-methyl-2-pyrrolidone. [Background technology]

[0002] N-methyl-2-pyrrolidone is a type of aprotic polar solvent. It has high solubility in various resins called engineering plastics. For this reason, N-methyl-2-pyrrolidone is widely used industrially, including as a cleaning agent in the electronic materials field. Known methods for producing N-methyl-2-pyrrolidone include reacting γ-butyrolactone with monomethylamine, and methods for producing γ-butyrolactone using a dehydrogenation reaction of 1,4-butanediol and a hydrogenation reaction of maleic anhydride.

[0003] Patent Document 1 describes a method in which acrylonitrile is reacted with carbon monoxide and methanol in the presence of octacarbonyldicobalt and various ligands. Non-Patent Document 1 describes a method in which acrylonitrile is reacted with carbon monoxide and methanol in the presence of octacarbonyldicobalt and pyridine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 4,331,612 [Non-patent literature]

[0005] [Non-Patent Document 1] BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 1967, page 135 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in order to carry out the carbonylation reaction of an α,β-unsaturated nitrile, an alcohol, and carbon monoxide using conventional techniques, the reaction had to be carried out under high pressure conditions, and therefore the conventional techniques for carrying out the carbonylation reaction of an α,β-unsaturated nitrile, an alcohol, and carbon monoxide were not suitable for industrial use.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for producing an ester compound, which can produce an ester compound by carbonylating an α,β-unsaturated nitrile, an alcohol, and carbon monoxide at a reaction pressure lower than that of the conventional technology. Another object of the present invention is to provide a method for producing 2-pyrrolidone and a method for producing N-methyl-2-pyrrolidone, which use the method for producing an ester compound of the present invention. [Means for solving the problem]

[0008] That is, the present invention relates to the following. [1] A method for producing an ester compound, comprising carbonylating an α,β-unsaturated nitrile represented by the following formula (1), an alcohol represented by the following formula (2), and carbon monoxide in the presence of a catalyst to produce at least one ester compound selected from the following formulas (3-1) and (3-2): the catalyst comprises a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table, and a bidentate phosphine ligand; The method for producing an ester compound, wherein the bidentate phosphine ligand is at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 1,1'-bis(di-iso-propylphosphino)ferrocene, and 1,2-bis(di-tert-butylphosphinomethyl)benzene.

[0009] [ka] (In formula (1), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, or a phenyl group.)

[0010] R4-OH (2) (In formula (2), R4 represents a hydrocarbon group having 1 to 10 carbon atoms.)

[0011] [ka] (In formulas (3-1) and (3-2), R1, R2, and R3 each represent the same group as in formula (1). R4 represents the same group as in formula (2).)

[0012] [2] The method for producing an ester compound according to [1], wherein the bidentate phosphine ligand is 1,2-bis(di-tert-butylphosphinomethyl)benzene.

[0013] [3] The method for producing an ester compound according to [1] or [2], wherein a molar ratio of the bidentate phosphine ligand to the compound having at least one element selected from Group 9 elements and Group 10 elements of the periodic table (number of moles of bidentate phosphine ligand / number of moles of compound having at least one element selected from Group 9 elements and Group 10 elements of the periodic table) is 1 to 10. [4] The method for producing an ester compound according to any one of [1] to [3], wherein the compound having at least one element selected from the group consisting of elements of Group 9 and Group 10 of the periodic table is a compound containing palladium.

[0014] [5] The method for producing an ester compound according to any one of [1] to [4], further comprising adding a Bronsted acid in the carbonylation reaction. [6] The method for producing an ester compound according to [5], wherein the Bronsted acid is p-toluenesulfonic acid.

[0015] [7] The method for producing an ester compound according to any one of [1] to [6], wherein in the formula (1), at least one of R1, R2 and R3 is a hydrogen atom. [8] The method for producing an ester compound according to [7], wherein in the formula (1), R1, R2, and R3 are all hydrogen atoms.

[0016] [9] The method for producing an ester compound according to any one of [1] to [8], wherein in the formula (2), R4 is one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a benzyl group.

[10] The method for producing an ester compound according to [9], wherein in the formula (2), R4 is a methyl group.

[11] The method for producing an ester compound according to any one of [1] to

[10] , wherein the carbonylation reaction is carried out in a reaction vessel in which the partial pressure of carbon monoxide gas is within the range of 0.5 to 10 MPaG.

[0017]

[12] A process for producing a 3-cyanopropionic acid ester by carbonylation reaction of acrylonitrile, an alcohol represented by the following formula (2), and carbon monoxide in the presence of a catalyst, the catalyst comprises a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table, and a bidentate phosphine ligand; A first step in which the bidentate phosphine ligand is at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 1,1′-bis(di-iso-propylphosphino)ferrocene, and 1,2-bis(di-tert-butylphosphinomethyl)benzene; and a second step of reacting the 3-cyanopropionic acid ester with hydrogen gas in the presence of a Ni catalyst or a Co catalyst.

[0018] R4-OH (2) (In formula (2), R4 represents a hydrocarbon group having 1 to 10 carbon atoms.)

[0019]

[13] The method for producing 2-pyrrolidone according to

[12] , wherein in the formula (2), R4 is a methyl group.

[14] The method for producing 2-pyrrolidone described in

[12] or

[13] , wherein the Ni catalyst or Co catalyst is a sponge nickel catalyst.

[0020]

[15] The method for producing 2-pyrrolidone according to any one of

[12] to

[14] , wherein in the second step, the 3-cyanopropionic acid ester is reacted with hydrogen gas in the presence of a Ni catalyst or a Co catalyst, and ammonia.

[0021]

[16] A step of producing 2-pyrrolidone by the method for producing 2-pyrrolidone according to any one of

[12] to

[15] ; and a third step of reacting the 2-pyrrolidone with methanol in the presence of an ammonium halide.

[17] The method for producing N-methyl-2-pyrrolidone according to

[16] , wherein the ammonium halide is ammonium chloride. Effect of the Invention

[0022] In the method for producing an ester compound of the present invention, a specific α,β-unsaturated nitrile, a specific alcohol, and carbon monoxide are carbonylated in the presence of a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table and a specific bidentate phosphine ligand. Therefore, at least one ester compound selected from formula (3-1) and formula (3-2) can be produced by carbonylation at a low reaction pressure. Therefore, the method for producing an ester compound of the present invention is suitable as an industrial method for producing an ester compound.

[0023] In the method for producing 2-pyrrolidone of the present invention, a 3-cyanopropionic acid ester can be produced by carrying out a carbonylation reaction at a low reaction pressure. The produced 3-cyanopropionic acid ester can then be used to produce 2-pyrrolidone that can be used for producing N-methyl-2-pyrrolidone. In the method for producing N-methyl-2-pyrrolidone of the present invention, 2-pyrrolidone is produced as an intermediate using the method for producing 2-pyrrolidone of the present invention, and then this intermediate is methylated to produce N-methyl-2-pyrrolidone, which is an industrially useful compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In order to solve the above problems, the present inventors have focused on a catalyst that promotes the carbonylation reaction of an α,β-unsaturated nitrile, an alcohol, and carbon monoxide and have conducted extensive research. As a result, it was found that a catalyst containing a compound having at least one element selected from the group 9 and 10 elements of the periodic table and the specific bidentate phosphine ligand shown below can be used. The specific bidentate phosphine ligand is at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 1,1'-bis(di-iso-propylphosphino)ferrocene, and 1,2-bis(di-tert-butylphosphinomethyl)benzene.

[0025] It is presumed that these specific bidentate phosphine ligands form a coordinate bond with a metal in a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table to form a stable complex. Although the details are not clear, the use of these specific bidentate phosphine ligands can lower the activation barrier in the step of adding an alcohol to an α,β-unsaturated nitrile, promoting the carbonylation reaction. For this reason, it is presumed that a sufficient reaction rate can be obtained even when the above carbonylation reaction is carried out at a low reaction pressure, and at least one ester compound selected from formula (3-1) and formula (3-2) is produced in a sufficient yield.

[0026] As a result of further investigation, the present inventors have confirmed that at least one ester compound selected from formula (3-1) and formula (3-2) can be produced at a low reaction pressure using industrially suitable apparatus and methods by carbonylating a specific α,β-unsaturated nitrile, a specific alcohol, and carbon monoxide in the presence of the above catalyst, and have thus arrived at the present invention.

[0027] The process for producing an ester compound, the process for producing 2-pyrrolidone, and the process for producing N-methyl-2-pyrrolidone of the present invention will be described in detail below. Note that the present invention is not limited to the following embodiments. [Method of producing ester compound] In the method for producing an ester compound of this embodiment, an α,β-unsaturated nitrile represented by the following formula (1), an alcohol represented by the following formula (2), and carbon monoxide are carbonylated in the presence of a catalyst, thereby producing at least one ester compound selected from the following formulas (3-1) and (3-2).

[0028] [ka] (In formula (1), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, or a phenyl group.)

[0029] R4-OH (2) (In formula (2), R4 represents a hydrocarbon group having 1 to 10 carbon atoms.)

[0030] [ka] (In formulas (3-1) and (3-2), R1, R2, and R3 each represent the same group as in formula (1). R4 represents the same group as in formula (2).)

[0031] (α,β-unsaturated nitrile) In the method for producing an ester compound according to the present embodiment, an α,β-unsaturated nitrile represented by formula (1) is used as a starting material. R1 to R3 in formula (1) are each independently selected from a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, and a phenyl group. The α,β-unsaturated nitrile represented by formula (1) in which at least one of R1 to R3 in formula (1) is a hydrogen atom is preferably used because an ester compound can be produced in high yield, and it is more preferable to use an α,β-unsaturated nitrile in which all of R1 to R3 are hydrogen atoms because an ester compound that can be easily used as a raw material for industrially useful compounds such as N-methyl-2-pyrrolidone can be obtained. Specific examples of the α,β-unsaturated nitrile represented by formula (1) include acrylonitrile, methacrylonitrile, and cinnamoyl nitrile. Among these, it is particularly preferable to use acrylonitrile in which all of R1 to R3 in formula (1) are hydrogen atoms.

[0032] (alcohol) In the method for producing an ester compound of the present embodiment, an alcohol represented by formula (2) is used. R4 in formula (2) is a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group is preferably an alkyl group, a cycloalkyl group, or an aralkyl group. As the alcohol represented by formula (2), R4 in formula (2) is preferably one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a benzyl group, because the ester compound can be produced in a high yield. In particular, R4 in formula (2) is preferably a methyl group, because an ester compound that can be easily used as a raw material for industrially useful compounds such as N-methyl-2-pyrrolidone can be obtained. Specific examples of the alcohol represented by formula (2) that can be used include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutyl alcohol, and sec-butyl alcohol.

[0033] In the method for producing an ester compound of this embodiment, it is preferable to use an alcohol represented by formula (2) as a solvent and carry out the reaction without adding any other solvent. When an alcohol represented by formula (2) is used as a solvent, the amount of the alcohol represented by formula (2) used is preferably an amount such that the concentration of the α,β-unsaturated nitrile in the mixture of the alcohol represented by formula (2) and the α,β-unsaturated nitrile represented by formula (1) is 0.01 to 10 mol / L, more preferably an amount such that the concentration is 0.1 to 5 mol / L, and even more preferably an amount such that the concentration is 0.5 to 2 mol / L. When the concentration of the α,β-unsaturated nitrile is 0.01 mol / L or more, it is not necessary to separate the alcohol and the ester compound by distilling off the excess alcohol after the carbonylation reaction by consuming a lot of energy, and the size of the reaction vessel (reaction kettle) is not excessively large, which is not advantageous in terms of cost. When the concentration of the α,β-unsaturated nitrile in the alcohol is 10 mol / L or less, there is no shortage of alcohol during the carbonylation reaction, and the ester compound can be produced in a high yield.

[0034] (solvent) In the method for producing an ester compound of the present embodiment, the carbonylation reaction may be carried out using a solvent other than the alcohol represented by formula (2). As the solvent used in the production method of the present embodiment, a chemical species that does not participate in the carbonylation reaction between the α,β-unsaturated nitrile represented by formula (1), the alcohol represented by formula (2), and carbon monoxide can be used.

[0035] Examples of solvents other than the alcohol represented by formula (2) include tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, n-propyl acetate, n-butyl acetate, n-heptane, acetonitrile, toluene, xylene, N-methylpyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, etc. Among these solvents, it is preferable to use any one selected from tetrahydrofuran, acetone, ethyl acetate, toluene, and xylene, since a particularly high yield can be obtained among these solvents.

[0036] When a solvent other than the alcohol represented by formula (2) is added to carry out the carbonylation reaction, the amount of the alcohol represented by formula (2) used is preferably 1 to 50 equivalents relative to the α,β-unsaturated nitrile represented by formula (1), more preferably 2 to 40 equivalents, and even more preferably 2 to 30 equivalents. When the amount of the alcohol used is 1 equivalent or more relative to the α,β-unsaturated nitrile represented by formula (1), the alcohol does not run short during the carbonylation reaction, and the ester compound can be produced in a high yield. When the amount of the alcohol used is 50 equivalents or less relative to the α,β-unsaturated nitrile represented by formula (1), it is not necessary to separate the alcohol and the ester compound by distilling off the excess alcohol after the carbonylation reaction by consuming a lot of energy, and the size of the reaction vessel (reaction kettle) is not excessively large, which is not advantageous in terms of cost.

[0037] When a solvent other than the alcohol represented by formula (2) is added to carry out the carbonylation reaction, the amount of the solvent other than the alcohol to be used is preferably an amount such that the concentration of the α,β-unsaturated nitrile relative to the total amount of the alcohol and the solvent other than the alcohol is 0.01 to 10 mol / L, more preferably an amount such that the concentration is 0.1 to 5 mol / L, and even more preferably an amount such that the concentration is 0.5 to 2 mol / L.

[0038] (Carbon monoxide) In the method for producing an ester compound of the present embodiment, it is preferable to use a gas containing carbon monoxide gas as a carbon monoxide supply source. The gas containing carbon monoxide gas may be only carbon monoxide gas, or may be a gas containing inert gas such as nitrogen gas or argon, hydrogen gas, etc. in addition to carbon monoxide gas. It is preferable that the gas containing carbon monoxide gas does not contain oxidizing gas such as air or oxygen gas. In the present embodiment, carbon monoxide gas produced by pyrolyzing used plastics may be used as carbon monoxide.

[0039] The amount of carbon monoxide used is, for example, preferably such that the partial pressure of carbon monoxide gas in a reaction vessel containing a mixture of an alcohol represented by formula (2) and an α,β-unsaturated nitrile represented by formula (1) and having a gas atmosphere containing carbon monoxide is within a range of 0.5 to 10 MPaG (gauge pressure), more preferably within a range of 1.0 to 10 MPaG, and even more preferably within a range of 2.0 to 5.0 MPaG. It is particularly preferable to carry out the carbonylation reaction while replenishing carbon monoxide consumed by the reaction so that the partial pressure of carbon monoxide gas in the reaction vessel during the reaction is maintained within a range of 2.0 to 5.0 MPaG.

[0040] When the partial pressure of carbon monoxide gas in the reaction vessel during the carbonylation reaction is 0.5 MPaG or more, the carbonylation reaction is likely to proceed. The partial pressure of carbon monoxide gas in the reaction vessel is preferably high in order to promote the carbonylation reaction. However, in order to make the partial pressure of carbon monoxide gas during the carbonylation reaction exceed 10 MPaG, it is necessary to use an expensive device. By making the partial pressure of carbon monoxide gas during the carbonylation reaction 10 MPaG or less, an ester compound can be produced using an industrially suitable device and method. In this embodiment, since the carbonylation reaction is promoted by the catalyst, a sufficient reaction rate can be obtained and an ester compound can be produced with a sufficient yield even if the partial pressure of carbon monoxide gas is 10 MPaG or less.

[0041] As the gas containing carbon monoxide gas, it is preferable to use only carbon monoxide gas. When the gas containing carbon monoxide gas is, for example, carbon monoxide gas produced by thermally decomposing used plastics, it may be a gas containing carbon monoxide gas and hydrogen gas. When a mixed gas containing carbon monoxide gas and hydrogen gas is used, the gas composition in the reaction vessel is preferably such that the partial pressure ratio of carbon monoxide gas to hydrogen gas is (hydrogen gas) / (carbon monoxide)=2 or less, and more preferably (hydrogen gas) / (carbon monoxide)=1 or less. When the partial pressure ratio of carbon monoxide gas to hydrogen gas in the reaction vessel during the carbonylation reaction is (hydrogen gas) / (carbon monoxide)=2 or less, it is possible to suppress the progress of the hydrogen reduction reaction and the decrease in the yield of the ester compound. When the partial pressure ratio of carbon monoxide gas to hydrogen gas during the carbonylation reaction is (hydrogen gas) / (carbon monoxide)=1 or less, it is possible to further suppress the generation of by-products due to the hydrogen reduction reaction. As a result, at least one ester compound selected from the formula (3-1) and the formula (3-2) is preferably obtained as a main product.

[0042] (Compound containing at least one element selected from elements of Groups 9 and 10 of the periodic table) In the production method of this embodiment, a compound containing at least one element selected from the group consisting of elements in Groups 9 and 10 of the periodic table is used as a catalyst. Examples of the compound containing at least one element selected from the group 9 elements of the periodic table include compounds containing at least one element selected from Co, Rh, and Ir, and it is particularly preferable to use a compound containing rhodium. Examples of the compound containing rhodium include rhodium(III) chloride and / or rhodium(III) nitrate.

[0043] Examples of the compound containing at least one element selected from the group 10 elements of the periodic table include compounds containing at least one element selected from Ni, Pd, and Pt, and it is particularly preferable to use a compound containing palladium. Examples of the compound containing palladium include at least one zero- or divalent palladium compound selected from palladium chloride (II), palladium nitrate (II), palladium sulfate (II), palladium acetate (II), bis(acetylacetonato)palladium (II) (Pd(acac)2), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3), and dipalladium(0)tris(dibenzylideneacetone)chloroform (Pd2(dba)3·CHCl3).

[0044] Among these compounds containing at least one element selected from Group 9 and Group 10 elements of the periodic table, it is preferable to use a compound containing palladium because it has a good effect of promoting the carbonylation reaction, and it is particularly preferable to use palladium chloride(II) and / or bis(acetylacetonato)palladium(II) (Pd(acac)2). The compound having at least one element selected from the group consisting of elements in Groups 9 and 10 of the periodic table contained in the catalyst may be of only one type, or of two or more types.

[0045] The amount of the compound having at least one element selected from Groups 9 and 10 of the periodic table is preferably 0.01 mol% to 2 mol%, more preferably 0.05 mol% to 1 mol%, and even more preferably 0.1 mol% to 0.3 mol% relative to the α,β-unsaturated nitrile represented by formula (1). When the amount of the compound having at least one element selected from Groups 9 and 10 of the periodic table is 0.01 mol% or more relative to the α,β-unsaturated nitrile represented by formula (1), the reaction promotion effect of the carbonylation reaction becomes remarkable. As a result, the yield of at least one ester compound selected from Formulas (3-1) and (3-2) is high. In addition, when the amount of the compound having at least one element selected from Groups 9 and 10 of the periodic table is 2 mol% or less, the amount of catalyst lost during recovery after the carbonylation reaction is small, which is economically preferable.

[0046] (Bidentate phosphine ligand) In the production method of this embodiment, a bidentate phosphine ligand is used as a catalyst. As the bidentate phosphine ligand, at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos), 1,1'-bis(di-iso-propylphosphino)ferrocene (DiPrPF), and 1,2-bis(di-tert-butylphosphinomethyl)benzene (DTBPMB) is used. Among these, it is preferable to use DTBPMB as the bidentate phosphine ligand, since it can produce an ester compound in a high yield.

[0047] The molar ratio of the bidentate phosphine ligand to the compound having at least one element selected from Groups 9 and 10 of the periodic table (molar number of bidentate phosphine ligand / molar number of compound having at least one element selected from Groups 9 and 10 of the periodic table) is preferably 1 to 10, more preferably 1 to 5, and even more preferably 2 to 5. When the molar ratio is within the above range, the proportion of the bidentate phosphine ligand in the catalyst is sufficiently ensured. Therefore, a stable complex in which the bidentate phosphine ligand and the metal in the compound having at least one element selected from Groups 9 and 10 of the periodic table are coordinated to each other is easily formed, and the carbonylation reaction is more effectively promoted, and the ester compound is obtained in a high yield.

[0048] (Bronsted acid) In the production method of this embodiment, it is preferable to further add a Bronsted acid in the carbonylation reaction, since the carbonylation reaction is more effectively promoted by adding a Bronsted acid. Examples of Bronsted acids include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; alkanoic acids having 2 to 12 carbon atoms; sulfonic acids such as methanesulfonic acid, chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, and p-toluenesulfonic acid; sulfonated ion exchange resins; perhalogen acids such as perchloric acid; and halogenated carboxylic acids such as trichloroacetic acid and trifluoroacetic acid. Among these Bronsted acids, it is preferable to use sulfonic acids, and more preferably p-toluenesulfonic acid, because the carbonylation reaction is effectively promoted.

[0049] The amount of the Bronsted acid used is preferably 0.1 mol% to 5.0 mol% relative to the α,β-unsaturated nitrile represented by formula (1), more preferably 1.5 mol% to 5.0 mol%, and even more preferably 3.0 mol% to 4.0 mol%. When the amount of the Bronsted acid used is 0.1 mol% or more relative to the α,β-unsaturated nitrile, the effect of activating the carbonylation reaction and increasing the reaction rate is remarkable. In addition, when the amount of the Bronsted acid used is 5.0 mol% or less relative to the α,β-unsaturated nitrile, corrosion of the equipment caused by the use of the Bronsted acid is less likely to occur, which is preferable.

[0050] (Reaction conditions) The reaction conditions for the carbonylation reaction to produce an ester compound can be appropriately determined depending on the α,β-unsaturated nitrile represented by formula (1), the alcohol represented by formula (2), the type and amount of catalyst used, and the like. The reaction temperature is preferably 50 to 250°C, more preferably 60 to 200°C, and even more preferably 70 to 190°C. When the reaction temperature is 50°C or higher, the carbonylation reaction that produces the ester compound is further promoted, and the reaction time can be shortened. In addition, when the reaction temperature is 50°C or higher, the ester compound represented by formula (3-1), which is easily usable as a raw material for industrially useful compounds, is easily produced, and this is preferable. When the reaction temperature is 250°C or lower, side reactions in the carbonylation reaction can be suppressed, and the ester compound can be produced in a high yield, and this is preferable. The partial pressure of carbon monoxide gas in the reaction vessel is preferably 0.5 to 10 MPaG, more preferably 1.0 to 10 MPaG, and further preferably 2.0 to 5.0 MPaG. By setting the partial pressure of carbon monoxide gas in the reaction vessel to 0.5 to 10 MPaG, the ester compound can be produced in a higher yield.

[0051] The reaction time is preferably 1 to 40 hours, more preferably 1 to 20 hours, and even more preferably 1 to 3 hours. When the reaction time is 1 hour or more, the conversion rate of the α,β-unsaturated nitrile represented by the general formula (1) becomes sufficiently high, and the ester compound can be produced in a higher yield and with a higher selectivity. When the reaction time is 40 hours or less, side reactions in the carbonylation reaction can be suppressed. When the reaction time is 1 to 3 hours, the ester compound can be produced in a high yield and good productivity can be obtained.

[0052] In the method for producing an ester compound of the present embodiment, a pressure-resistant reaction apparatus such as an autoclave can be used as the reaction apparatus.

[0053] (Ester compounds) In the method for producing an ester compound according to the present embodiment, an ester compound represented by formula (3-1) and / or formula (3-2) is produced. In formulas (3-1) and (3-2), R1, R2, and R3 each represent the same group as in formula (1). R4 represents the same group as in formula (2). In the production method of this embodiment, it is preferable to produce the ester compound represented by formula (3-1) as the main product, which is easily usable as a raw material for industrially useful compounds, between the ester compound represented by formula (3-1) and the ester compound represented by formula (3-2). Among the ester compounds represented by formula (3-1), for example, 3-cyanopropionic acid ester in which all of R1 to R3 are hydrogen atoms can be used in the production method of 2-pyrrolidone described later.

[0054] The production ratio (molar ratio) of the ester compound represented by formula (3-1) to the ester compound represented by formula (3-2) produced in the production method of this embodiment (ester compound represented by formula (3-1) / ester compound represented by formula (3-2)) is preferably at least 1, more preferably at least 1.5. The above molar ratio can be controlled by the α,β-unsaturated nitrile represented by formula (1), the alcohol represented by formula (2), the type and amount of catalyst used, and the reaction conditions.

[0055] In the method for producing an ester compound of the present embodiment, when acrylonitrile is used as the α,β-unsaturated nitrile represented by formula (1) and methanol is used as the alcohol represented by formula (2), methyl 3-cyanopropionate represented by the following formula (4-1) and / or an ester compound represented by the following formula (4-2) are produced.

[0056] [ka] (In formula (4-1), Me is a methyl group.) (In formula (4-2), Me is a methyl group.)

[0057] In the method for producing an ester compound according to the present embodiment, a separation step may be carried out, as necessary, by a known method, to separate the ester compound represented by formula (3-1) and / or formula (3-2) from the reaction solution obtained by carrying out the carbonylation reaction described above. When both the ester compound represented by formula (3-1) and the ester compound represented by formula (3-2) are produced by the carbonylation reaction described above, a separation step may be carried out, as necessary, by a known method, to separate them.

[0058] In the method for producing an ester compound of this embodiment, an α,β-unsaturated nitrile represented by formula (1), an alcohol represented by formula (2), and carbon monoxide are carbonylated in the presence of a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table and a specific bidentate phosphine ligand. Therefore, the carbonylation reaction can be carried out at a low reaction pressure to produce an ester compound represented by formula (3-1) and / or the following formula (3-2). Therefore, the method for producing an ester compound of this embodiment is suitable as an industrial method for producing an ester compound.

[0059] [Method of manufacturing 2-pyrrolidone] The method for producing 2-pyrrolidone of the present embodiment includes a first step of producing a 3-cyanopropionic acid ester by carbonylating acrylonitrile, an alcohol represented by formula (2), and carbon monoxide in the presence of the catalyst, and a second step of reacting the produced 3-cyanopropionic acid ester with hydrogen gas in the presence of a Ni catalyst or a Co catalyst.

[0060] "1st process" (3-Cyanopropionic acid ester) In the first step, a 3-cyanopropionic acid ester is produced by using acrylonitrile (wherein all of R1 to R3 are hydrogen atoms) as the α,β-unsaturated nitrile represented by formula (1) in the above-mentioned method for producing an ester compound.

[0061] (alcohol) In the first step, an alcohol represented by formula (2) is used, as in the above-mentioned method for producing an ester compound. R4 in formula (2) is a leaving group that is eliminated when 2-pyrrolidone is produced from 3-cyanopropionic acid ester in the second step. For this reason, R4 is preferably a methyl group or an ethyl group, which are groups that are easily eliminated, and more preferably a methyl group.

[0062] "Second process" In the second step, the cyano group (-CN) of the 3-cyanopropionic acid ester is reduced to produce a primary amine, which then undergoes a dealcoholization reaction to close the ring (cyclization reaction) to produce 2-pyrrolidone.

[0063] (Hydrogen gas) A gas containing hydrogen gas is used as a supply source of hydrogen gas. The gas containing hydrogen gas may be a gas containing only hydrogen gas, or may be a gas containing, in addition to hydrogen gas, an inert gas such as nitrogen or argon, a reducing gas such as carbon monoxide gas, or an oxidizing gas such as air or oxygen. In this embodiment, hydrogen gas produced by gasifying used plastics may be used as the hydrogen gas.

[0064] The amount of hydrogen gas used is preferably within a range in which the partial pressure of hydrogen gas in a reaction vessel containing, for example, 3-cyanopropionic acid ester and a Ni catalyst or a Co catalyst and in which the hydrogen gas-containing gas atmosphere is 0.2 MPaG (gauge pressure) or more, more preferably within a range of 0.5 MPaG or more. It is particularly preferable to carry out the reaction while replenishing hydrogen gas consumed by the reaction so that the partial pressure of hydrogen gas in the reaction vessel during the reaction is maintained within a range of less than 1 MPaG. Even if the partial pressure of hydrogen gas in the reaction vessel during the reaction is 1 MPaG or more, there is no problem in the progress of the reaction in the second step, but it is advantageous in terms of safety if it is less than 1 MPaG. If the partial pressure of hydrogen gas during the reaction is 0.2 MPaG or more, more preferably 0.5 MPaG or more, a sufficient reaction rate can be obtained in the second step.

[0065] (Ni catalyst or Co catalyst) As the Ni catalyst or Co catalyst, it is preferable to use a sponge nickel catalyst or a sponge cobalt catalyst, and it is particularly preferable to use a sponge nickel catalyst because it has a good effect of promoting the reaction in the second step. The amount of Ni catalyst or Co catalyst used is preferably 5 to 40 mass %, more preferably 5 to 30 mass %, and even more preferably 10 to 20 mass %, based on the mass of the 3-cyanopropionic acid ester. When the amount of Ni catalyst or Co catalyst is 5 mass % or more, the reaction promotion effect in the second step becomes significant. Even if the amount of Ni catalyst or Co catalyst exceeds 40 mass %, there is no problem in the reaction promotion function in the second step, but it is disadvantageous in terms of economy.

[0066] (ammonia) In the second step, it is preferable to react the 3-cyanopropionic acid ester with hydrogen gas in the presence of a Ni catalyst or Co catalyst and ammonia. By reacting with hydrogen gas in the presence of ammonia, the amount of secondary amines and tertiary amines produced as by-products during the reaction in the second step is reduced, and the yield and selectivity of 2-pyrrolidone are increased. The amount of ammonia used is preferably 0.1 to 0.7 equivalents relative to the 3-cyanopropionic acid ester, more preferably 0.1 to 0.5 equivalents, and even more preferably 0.2 to 0.5 equivalents. When the amount of ammonia used is 0.1 equivalents or more relative to the 3-cyanopropionic acid ester, the effect of reducing the amount of by-products produced in the second step becomes significant, and the yield of 2-pyrrolidone becomes higher. When the amount of ammonia used is 0.7 equivalents or less, the amount of ammonia loss that cannot be recovered is small when ammonia is recovered and utilized, which is preferable.

[0067] (solvent) The second step may be a step of reacting the 3-cyanopropionic acid ester with hydrogen gas in a state in which the 3-cyanopropionic acid ester, the Ni catalyst or Co catalyst, and the ammonia used as necessary are dissolved or dispersed in a solvent. When a solvent is used together with ammonia in the second step, the ammonia may be dissolved in the solvent in advance.

[0068] As the solvent, for example, protic polar solvents such as water and alcohol, aprotic polar solvents such as tetrahydrofuran and acetone, non-polar solvents such as hexane and benzene, etc. As the solvent, water or alcohol is preferably used, and alcohol is more preferably used.

[0069] The alcohol used as the solvent is not particularly limited, and for example, methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutyl alcohol, sec-butyl alcohol, etc. can be used. When an alcohol is used as a solvent, the alcohol used as the solvent can be recovered after the second step together with R4-OH, which is by-produced when 2-pyrrolidone is produced from 3-cyanopropionic acid ester in the second step. Therefore, the alcohol used as the solvent can be easily reused, which is preferable. When the alcohol used as the solvent and the R4-OH by-produced together with 2-pyrrolidone are the same, the alcohol can be recovered more easily and efficiently after the second step. For this reason, it is preferable that the alcohol used as the solvent is the same as the alcohol used as the raw material in the first step.

[0070] (Reaction conditions) The reaction conditions in the second step may be any conditions that allow the 3-cyanopropionic acid ester to react with hydrogen gas in the presence of a Ni catalyst or a Co catalyst. The reaction temperature is preferably 50°C to 180°C, more preferably 100°C to 150°C, and even more preferably 130°C to 150°C. If the reaction temperature is 50°C or higher, when the cyano group (-CN) of the 3-cyanopropionic acid ester is reduced to generate a primary amine, the ring-closing reaction due to the dealcoholization reaction is promoted. As a result, the amount of by-products such as secondary amines produced in the second step is reduced, and 2-pyrrolidone can be produced in a higher yield. If the reaction temperature is 180°C or lower, side reactions such as the condensation reaction of 2-pyrrolidone can be suppressed, which is preferable.

[0071] The reaction time in the second step is preferably 0.5 to 3 hours, more preferably 1 to 3 hours, and even more preferably 1 to 2 hours. When the reaction time is 0.5 hours or more, the reduction and ring-closing reaction of the 3-cyanopropionic acid ester in the second step proceeds sufficiently, so that 2-pyrrolidone can be produced in a higher yield. When the reaction time is 3 hours or less, 2-pyrrolidone can be produced efficiently, and good productivity can be obtained.

[0072] In the second step, a pressure-resistant reaction apparatus such as an autoclave can be used as the reaction apparatus.

[0073] In the method for producing 2-pyrrolidone according to the present embodiment, a 3-cyanopropionic acid ester is produced by the above-mentioned method for producing an ester compound, and thus a 3-cyanopropionic acid ester can be obtained by a carbonylation reaction at a low reaction pressure. The produced 3-cyanopropionic acid ester can then be used to produce 2-pyrrolidone that can be used for producing N-methyl-2-pyrrolidone.

[0074] [Method of producing N-methyl-2-pyrrolidone] The method for producing N-methyl-2-pyrrolidone of the present embodiment includes a step of producing 2-pyrrolidone by the above-mentioned method for producing 2-pyrrolidone, and a third step of reacting the produced 2-pyrrolidone with methanol in the presence of ammonium halide.

[0075] "3rd process" (methanol) The amount of methanol used is preferably 1 mol to 20 mol, more preferably 1 mol to 10 mol, and even more preferably 1 mol to 5 mol, per mol of 2-pyrrolidone. When the amount of methanol used is 1 mol or more per mol of 2-pyrrolidone, there is no shortage of methanol, and N-methyl-2-pyrrolidone can be obtained in high yield. When the amount of methanol used is 20 mol or less per mol of 2-pyrrolidone, the size of the reaction vessel used in the third step can be reduced, which is preferable.

[0076] (Ammonium Halides) As the ammonium halide, for example, ammonium bromide, ammonium chloride, etc. can be used. It is preferable to use ammonium chloride since N-methyl-2-pyrrolidone can be obtained in high yield.

[0077] The amount of ammonium halide used is preferably 0.01 mol to 0.50 mol, more preferably 0.10 mol to 0.40 mol, and even more preferably 0.15 mol to 0.30 mol per mol of 2-pyrrolidone. When the amount of ammonium halide used is 0.01 mol or more per mol of 2-pyrrolidone, the effect of promoting the methylation reaction of 2-pyrrolidone becomes significant, and N-methyl-2-pyrrolidone is obtained in a high yield. When the amount of ammonium halide used is 0.50 mol or less per mol of 2-pyrrolidone, the reaction equipment used in the third step is less likely to be corroded, which is preferable.

[0078] (Reaction conditions) The reaction conditions in the third step may be any conditions that allow 2-pyrrolidone to react with methanol in the presence of ammonium halide. The reaction temperature is preferably 250°C to 350°C, more preferably 270°C to 350°C, and even more preferably 270°C to 320°C. When the reaction temperature is 250°C or higher, the methylation reaction of 2-pyrrolidone is promoted, and N-methyl-2-pyrrolidone is obtained in a high yield. When the reaction temperature is 350°C or lower, the reaction equipment used in the third step is less likely to be corroded, which is preferable.

[0079] The reaction time in the third step is preferably 2 to 7 hours, more preferably 2 to 6 hours, and even more preferably 3 to 5 hours. When the reaction time is 2 hours or more, the methylation reaction of 2-pyrrolidone proceeds sufficiently, so that N-methyl-2-pyrrolidone can be produced in a higher yield. When the reaction time is 7 hours or less, N-methyl-2-pyrrolidone can be produced efficiently, and good productivity can be obtained.

[0080] In the method for producing N-methyl-2-pyrrolidone of this embodiment, a known reaction apparatus can be used as the reaction apparatus.

[0081] In the method for producing N-methyl-2-pyrrolidone according to this embodiment, 2-pyrrolidone as an intermediate is produced using the above-described method for producing 2-pyrrolidone, and this is methylated to produce N-methyl-2-pyrrolidone, which is an industrially useful compound.

Examples

[0082] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. Note that the present invention is not limited only to the following Examples.

[0083] [Analysis method] For the "ester compound", "2-pyrrolidone", and "N-methyl-2-pyrrolidone" produced by the following method for producing an ester compound, method for producing 2-pyrrolidone, and method for producing N-methyl-2-pyrrolidone, the conversion rate and yield were determined. For "N-methyl-2-pyrrolidone", the selectivity was also determined. Specifically, under the following analysis conditions, the raw materials and target products in the reaction solution were analyzed using high performance liquid chromatography (HPLC), quantified using the absolute calibration curve method, and each value was calculated using the results.

[0084] <HPLC analysis conditions> Column: Shodex (registered trademark) RSpak KS-801 (manufactured by Showa Denko K.K.) Column size: 8.0 mm × 250 mm Column temperature: 40°C Eluent: Pure water Flow rate of eluent: 1.0 ml / min Detector: UV (ultraviolet) 210 nm, RI (differential refractive index)

[0085] [Method for producing ester compound] (Example 1) In a 100 ml stainless steel reaction vessel equipped with an autoclave (manufactured by Nitto Koatsu Co., Ltd.), 1.73 g of acrylonitrile (manufactured by Showa Denko K.K.), 25.7 g of methanol (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent), 0.0198 g of bis(acetylacetonato)palladium(II) (Pd(acac)2), 0.1027 g of 1,2-bis(di-tert-butylphosphinomethyl)benzene (DTBPMB), and 0.1981 g of p-toluenesulfonic acid (PTSA) were placed in the proportions shown in Table 1.

[0086] [Table 1]

[0087] After replacing the inside of the reaction vessel with carbon monoxide gas, the partial pressure of carbon monoxide in the reaction vessel was set to 4 MPaG (gauge pressure) and heated to 120°C. The inside of the reaction vessel was then set to 90°C, and the contents were reacted for 3 hours while being stirred. The pressure drop in the reaction vessel was then measured, and the reaction liquid in the reaction vessel was cooled to room temperature and the residual pressure was released. The reaction liquid in the reaction vessel was then subjected to HPLC analysis using the above-mentioned analytical method.

[0088] (Examples 2 to 8, Comparative Examples 1 to 7) The reaction was carried out in the same manner as in Example 1, except that the bidentate phosphine ligand and carbon monoxide-containing gas shown in Table 1 were used, and the reaction was carried out at the amount of carbon monoxide-containing gas used, reaction temperature, and reaction time shown in Table 1. In Example 6, a mixed gas of carbon monoxide gas and hydrogen gas was used as the carbon monoxide-containing gas. Thereafter, the reaction solution in the reaction vessel was subjected to HPLC analysis by the above-mentioned analytical method.

[0089] Table 1 shows the "conversion rate of acrylonitrile," "yield of ester compounds (yield of methyl 3-cyanopropionate represented by formula (4-1) (yield of 3-CPM) and yield of ester compounds represented by formula (4-2) (yield of iso isomer))," and "ratio of yield of 3-CPM to yield of iso isomer (n / i ratio)," which were calculated from the results of HPLC analysis of the reaction solutions obtained in Examples 1 to 8 and Comparative Examples 1 to 7.

[0090] The amounts (mol%) of compounds having group 9 and 10 elements, bidentate phosphine ligands, and Bronsted acids used in Table 1 are the molar percentages relative to acrylonitrile. The amount of alcohol used (mol / L) in Table 1 is the molar concentration of acrylonitrile in a mixture of acrylonitrile and alcohol. The amount of carbon monoxide-containing gas used (MPaG) in Table 1 is the partial pressure (gauge pressure) of carbon monoxide or hydrogen gas in the reaction vessel at the start of the reaction.

[0091] The following symbols in Table 1 represent the compounds shown below. "Pd(acac)2" Bis(acetylacetonato)palladium(II) (Tokyo Chemical Industry Co., Ltd.) "PTSA" p-Toluenesulfonic acid (FUJIFILM Wako Pure Chemical Corporation)

[0092] "DTBPMB" 1,2-bis(di-tert-butylphosphinomethyl)benzene (manufactured by Tokyo Chemical Industry Co., Ltd.) represented by the following structural formula "DiPrPF" 1,1'-bis(di-iso-propylphosphino)ferrocene (manufactured by Tokyo Chemical Industry Co., Ltd.) represented by the following structural formula "Xantphos" is 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (manufactured by Tokyo Chemical Industry Co., Ltd.) represented by the following structural formula.

[0093] [ka] (In formula (DTBPMB), t-Bu is a tert-butyl group.) (In formula (DiPrPF), i-Pr is an isopropyl group.) (In the formula (Xantphos), Ph is a phenyl group.)

[0094] "DPPP" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "DPPB" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "DPPF" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "DtBuPF" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "DPEPhos" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "DIOP" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.) "tBu-Xantphos" is a compound represented by the following structural formula (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0095] [ka] (In formula (DPPF), Ph is a phenyl group.) (In formula (DtBuPF), t-Bu is a tert-butyl group.) (In formula (DPEPhos), Ph is a phenyl group.) (In formula (DIOP), Ph is a phenyl group.) (In the formula (tBu-Xantphos), t-Bu is a tert-butyl group.)

[0096] As shown in Table 1, in Examples 1 to 8 in which (DTBPMB), (DiPrPF), and (Xantphos) were used as the bidentate phosphine ligand, 3-CPM was produced. In contrast, 3-CPM was not produced in Comparative Examples 2 and 4 to 7. Moreover, although 3-CPM was produced in Comparative Examples 1 and 3, the conversion of acrylonitrile was low and the yield of 3-CPM was also low compared to Examples 1 to 8.

[0097] In Example 2, in which (DTBPMB) was used as the bidentate phosphine ligand, the conversion of acrylonitrile was high, and the yield of 3-CPM and the yield of the iso form were also high, despite the short reaction time, compared with Example 7, in which (DiPrPF) was used. In Example 2, in which (DTBPMB) was used as the bidentate phosphine ligand, the conversion of acrylonitrile was higher, and the yield of 3-CPM and the yield of the iso form were also higher than in Example 8, in which (Xantphos) was used.

[0098] From Examples 1 to 4, it was confirmed that when (DTBPMB) was used as the bidentate phosphine ligand, the higher the reaction temperature, the higher the yield of 3-CPM and the higher the n / i ratio. From Examples 3 and 5, it was confirmed that when (DTBPMB) was used as the bidentate phosphine ligand, increasing the partial pressure of carbon monoxide in the reaction vessel increased the conversion of acrylonitrile, and increased the yield of 3-CPM and the yield of the iso isomer. From Examples 5 and 6, it was confirmed that when (DTBPMB) was used as a bidentate phosphine ligand, the conversion rate of acrylonitrile was increased by including hydrogen gas in the gas containing carbon monoxide, and the yield of 3-CPM and the yield of the iso form were increased. From this, it was confirmed that even when the gas containing carbon monoxide gas includes hydrogen gas, the carbonylation reaction of acrylonitrile proceeds efficiently and the production of propionitrile due to the hydrogen reduction reaction of acrylonitrile is suppressed.

[0099] [Method of manufacturing 2-pyrrolidone] Example 9 A stainless steel reaction vessel having an internal volume of 100 ml equipped with an autoclave (manufactured by Nitto Koatsu Co., Ltd.) was charged with 1.5 g of methyl 3-cyanopropionate (3-CPM) produced in Example 4, 20.0 g of methanol (special grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.28 g of sponge nickel catalyst (product name: R-200, manufactured by Nikko Rica Corporation), and 1.22 g of 7N ammonia methanol solution (manufactured by Tokyo Chemical Industry Co., Ltd.) in the proportions shown in Table 2.

[0100] [Table 2]

[0101] After replacing the inside of the reaction vessel with hydrogen gas, the partial pressure of hydrogen in the reaction vessel was set to 0.8 MPaG (gauge pressure), the temperature was set to 130°C, and the contents were reacted for 1 hour while stirring. Next, the pressure drop in the reaction vessel was measured, and the reaction liquid in the reaction vessel was cooled to room temperature and the residual pressure was released. After that, the reaction liquid in the reaction vessel was subjected to the above-mentioned HPLC analysis.

[0102] (Examples 10 to 12) The reaction was carried out in the same manner as in Example 9, except that the amount of ammonia used was as shown in Table 2 and the reaction temperature was as shown in Table 2. Then, the reaction solution in the reaction vessel was subjected to HPLC analysis by the above-mentioned analytical method.

[0103] The "conversion rate of 3-CPM" and "yield of 2-pyrrolidone" calculated from the results of HPLC analysis of the reaction solutions obtained in Examples 9 to 12 are shown in Table 2. The amount of catalyst used (mass %) in Table 2 is the ratio of the mass of sponge nickel catalyst to the mass of 3-CPM. The amounts of ammonia and methanol used (equivalents) in Table 2 are equivalents to 1 equivalent of 3-CPM. The amount of methanol used (equivalents) in Table 2 is the amount supplied as methanol to the reaction vessel, and does not include the amount of methanol supplied as ammonia methanol. The hydrogen pressure (MPaG) in Table 2 is the partial pressure (gauge pressure) of hydrogen gas in the reaction vessel at the start of the reaction.

[0104] As shown in Table 2, in Examples 9 and 11, in which hydrogen gas was reacted in the presence of ammonia, the yield of 2-pyrrolidone was 90% or more, and the yield of 2-pyrrolidone was higher than that in Examples 10 and 12, in which no ammonia was used. Moreover, as shown in Table 2, Example 9 in which the reaction temperature was 130°C had a higher yield of 2-pyrrolidone than Example 11 in which the reaction temperature was 100°C. Moreover, as shown in Table 2, Example 10 in which the reaction temperature was 130°C had a higher yield of 2-pyrrolidone than Example 12 in which the reaction temperature was 100°C.

[0105] [Method of producing N-methyl-2-pyrrolidone] (Example 13) In a 100 ml stainless steel reaction vessel equipped with an autoclave (manufactured by Nitto Koatsu Co., Ltd.), 10.0 g of 2-pyrrolidone produced in Example 9, 7.5 g of methanol (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., special grade reagent), and 1.0 g of ammonium chloride (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., special grade reagent) were placed in the proportions shown in Table 3. The contents in the reaction vessel were reacted for 2.0 hours at a reaction temperature of 275° C. while stirring. Thereafter, the reaction solution in the reaction vessel was cooled to room temperature, and the reaction solution in the reaction vessel was subjected to the above-mentioned HPLC analysis.

[0106] [Table 3]

[0107] (Examples 14 to 16) The reaction was carried out in the same manner as in Example 13, except that the amounts of 2-pyrrolidone, methanol, and ammonium halide used were shown in Table 3, and the reaction time was shown in Table 3. Then, the reaction solution in the reaction vessel was subjected to HPLC analysis by the above-mentioned analytical method.

[0108] The "conversion rate of 2-pyrrolidone" and "yield and selectivity of N-methyl-2-pyrrolidone (NMP)" calculated from the results of HPLC analysis of the reaction solutions obtained in Examples 13 to 16 are shown in Table 3. The molar ratio of methanol and the molar ratio of ammonium halide in Table 3 are the ratio of the amount (mol) of each compound to the amount (mol) of 2-pyrrolidone.

[0109] As shown in Table 3, N-methyl-2-pyrrolidone (NMP) was obtained in a high yield of 65% or more by reacting 2-pyrrolidone with methanol in the presence of ammonium chloride.

Claims

1. The present invention relates to a method for producing an ester compound, comprising the steps of: subjecting an α,β-unsaturated nitrile represented by the following formula (1), an alcohol represented by the following formula (2), and carbon monoxide to a carbonylation reaction in the presence of a catalyst to produce ester compounds represented by the following formulas (3-1) and (3-2): the catalyst comprises a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table, and a bidentate phosphine ligand; The method for producing an ester compound, wherein the bidentate phosphine ligand is at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 1,1'-bis(di-iso-propylphosphino)ferrocene, and 1,2-bis(di-tert-butylphosphinomethyl)benzene. 【Chemistry 1】 (In formula (1), R １ , R ２ , R ３ are all hydrogen atoms.) R ４ -OH (2) (In formula (2), R ４ represents a hydrocarbon group having 1 to 10 carbon atoms. 【Chemistry 2】 (In the formulas (3-1) and (3-2), R １ , R ２ , R ３ Each of R represents the same group as in formula (1). ４ represents the same group as in formula (2).

2. The method for producing an ester compound according to claim 1, wherein the bidentate phosphine ligand is 1,2-bis(di-tert-butylphosphinomethyl)benzene.

3. 3. The method for producing an ester compound according to claim 1 or 2, wherein a molar ratio of the bidentate phosphine ligand to the compound having at least one element selected from Group 9 elements and Group 10 elements of the periodic table (number of moles of bidentate phosphine ligand / number of moles of compound having at least one element selected from Group 9 elements and Group 10 elements of the periodic table) is 1 to 10.

4. The method for producing an ester compound according to any one of claims 1 to 3, wherein the compound having at least one element selected from the group consisting of elements of Group 9 and Group 10 of the periodic table is a compound containing palladium.

5. The method for producing an ester compound according to any one of claims 1 to 4, wherein a Bronsted acid is further added in the carbonylation reaction.

6. The method for producing an ester compound according to claim 5, wherein the Bronsted acid is p-toluenesulfonic acid.

7. In the formula (2), R ４ is one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a benzyl group.

8. In the formula (2), R ４ The method for producing an ester compound according to claim 7, wherein is a methyl group.

9. The method for producing an ester compound according to any one of claims 1 to 8, wherein the carbonylation reaction is carried out in a reaction vessel in which the partial pressure of carbon monoxide gas is within a range of 0.5 to 10 MPaG.

10. This is a process for producing a 3-cyanopropionic acid ester by carbonylating acrylonitrile, an alcohol represented by the following formula (2), and carbon monoxide in the presence of a catalyst, the catalyst comprises a compound having at least one element selected from Group 9 and Group 10 elements of the periodic table, and a bidentate phosphine ligand; A first step in which the bidentate phosphine ligand is at least one selected from the group consisting of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 1,1'-bis(di-iso-propylphosphino)ferrocene, and 1,2-bis(di-tert-butylphosphinomethyl)benzene; and a second step of reacting the 3-cyanopropionic acid ester with hydrogen gas in the presence of a Ni catalyst or a Co catalyst. R ４ -OH (2) (In formula (2), R ４ represents a hydrocarbon group having 1 to 10 carbon atoms.

11. In the formula (2), R ４ The method for producing 2-pyrrolidone according to claim 10, wherein is a methyl group.

12. The method for producing 2-pyrrolidone according to claim 10 or 11, wherein the Ni catalyst or Co catalyst is a sponge nickel catalyst.

13. The method for producing 2-pyrrolidone according to any one of claims 10 to 12, wherein in the second step, the 3-cyanopropionic acid ester is reacted with hydrogen gas in the presence of a Ni catalyst or a Co catalyst, and ammonia.

14. A process for producing 2-pyrrolidone by using the process for producing 2-pyrrolidone according to any one of claims 10 to 13; and a third step of reacting the 2-pyrrolidone with methanol in the presence of an ammonium halide.

15. The method for producing N-methyl-2-pyrrolidone according to claim 14, wherein the ammonium halide is ammonium chloride.

Images