Methylenedianiline compound production method

Abstract

To provide a new method for producing a methylenedianiline compound without the need for formaldehyde.SOLUTION: There is provided a method for producing a methylenedianiline compound, characterized by heating an aniline compound to 25-100°C under a carbon dioxide partial pressure of 0.005-10 MPa (absolute pressure) in the presence of a reducing agent and a catalyst, and then adding an acid and heating to 25-100°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a methylenedianiline compound. [Background technology]

[0002] Methylenedianiline compounds are industrially useful compounds that are used as raw materials for diphenylmethane diisocyanate, which is the main raw material for synthetic resins (polyurethanes), as epoxy resin curing agents, dyes, etc. Methods for synthesizing methylenedianiline compounds have been reported, for example, by reacting an aniline compound with formaldehyde and then reacting the resulting mixture in the presence of a hydrochloric acid, kaolinite, or zeolite catalyst (e.g., Patent Document 1, Patent Document 2, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-63915 [Patent Document 2] U.S. Patent No. 3,476,806 [Non-Patent Document 1] D.Bahulayan et al,Green Chem.,1(1999)191. Summary of the Invention [Problem to be solved by the invention]

[0004] The methylenedianiline compound manufacturing methods described in the above documents all use formaldehyde as a raw material to be reacted with aniline, but formaldehyde is a compound that not only causes sick house syndrome and sick car syndrome, but is also suspected of being carcinogenic. Therefore, if formaldehyde remains in the product during the manufacturing process, there is a risk of harming health, and there is a demand for reducing its use and finding alternative raw materials.

[0005] The present invention has been made in view of the above circumstances, and provides a method for producing a methylenedianiline compound without using formaldehyde. [Means for solving the problem]

[0006] The present inventors have investigated methods for producing methylenedianiline compounds from carbon dioxide and aniline. As a result, they have found the following method for producing a methylenedianiline compound, which uses carbon dioxide as an alternative to formaldehyde, and have completed the present invention. That is, one aspect of the present invention relates to the following method for producing a methylenedianiline compound. [1] In the presence of a reducing agent and a catalyst, the reaction is carried out under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure) according to the following formula (1):

[0007] [ka]

[0008] [In the above formula, X 1 ~X 5 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. 1 ~X 3 At least one of these represents a hydrogen atom. to 25 to 300°C, and then an acid is added thereto and the mixture is heated to 25 to 300°C,

[0009] [ka]

[0010] [In the above formula, X 1 ~X 10each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. 1 ~X 3 At least one of these represents an amino group, and X 6 ~X 8 At least one of these represents an amino group. A method for producing a methylenedianiline compound represented by the formula: [2] A method for producing a hydroxybenzoate represented by the following formula (3), characterized in that aniline is heated to 25 to 300°C under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure) in the presence of a reducing agent and a catalyst, and then an acid is added and the mixture is heated to 25 to 300°C:

[0011] [ka]

[0012] A method for producing methylenedianiline represented by the formula: [3] A method for producing 4,4'-methylenedianiline, comprising heating aniline to 25 to 300°C in the presence of a reducing agent and a catalyst under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure), and then adding an acid and heating the mixture to 25 to 300°C. [4] The method for producing a methylenedianiline compound according to the above [1], [2] and [3], wherein the reducing agent is one or more reducing agents selected from the group consisting of compounds having an H-Si bond or compounds having an H-B bond. [5] The method for producing a methylenedianiline compound according to the above [1], [2] and [3], wherein the reducing agent is one or two reducing agents selected from the group consisting of diphenylsilane and 9-borabicyclo[3.3.1]nonane. [6] The method for producing a methylenedianiline compound according to the above [1], [2] and [3], wherein the catalyst is one or more catalysts selected from the group consisting of alkyl onium salts and basic catalysts. [7] The method for producing a methylenedianiline compound according to the above [5], wherein the anion species of the alkyl onium salt is a phosphate anion, a carboxylate anion, or a bicarbonate ion. [8] The method for producing a methylenedianiline compound according to the above items [1], [2] and [3], wherein the catalyst is one or more catalysts selected from the group consisting of tributylmethylammonium dibutylphosphate, tetrabutylammonium acetate, tetrabutylammonium benzoate, tetramethylammonium acetate, choline acetate and tetraethylammonium bicarbonate. [9] The method for producing a methylenedianiline compound according to the above items [1], [2] and [3], wherein the acid is an inorganic acid.

[10] The method for producing a methylenedianiline compound according to the above [1], [2] and [3], wherein the acid is hydrochloric acid.

[11] The method for producing a methylenedianiline compound according to the above items [1], [2] and [3], further comprising using a solvent, the amount of the solvent being 0.1 to 100 parts by mass per part by mass of the aniline compound represented by the formula (1). [Effects of the Invention]

[0013] According to the present invention, a novel technique for producing a methylenedianiline compound without using formaldehyde can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less."

[0015] The present invention relates to a method for producing a 4,4'-methylenedianiline compound represented by the above formula (2), which comprises heating an amine compound represented by the above formula (1) to 25 to 300°C in the presence of a reducing agent and a catalyst under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure), and then adding an acid and heating the mixture to 25 to 300°C.

[0016] The aniline compound represented by the above formula (1), which is a raw material used in the production method of the present invention, may be a commercially available product or may be synthesized by a generally known method.

[0017] The purity of the aniline compound represented by the above formula (1), which is a raw material used in the production method of the present invention, is not particularly limited, but is preferably 95% by mass or more in terms of ease of purification in the purification step after the reaction.

[0018] In the aniline compound represented by the above formula (1), which is a raw material for the production method of the present invention, X 1 ~X 5 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. 1 ~X 3 At least one of these represents a hydrogen atom.

[0019] X 1 ~X 5 The halogen atom in is not particularly limited, but examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0020] X 1 ~X 5The alkyl group having 1 to 6 carbon atoms in the formula (I) is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a tert-butyl group, a pentyl group, a 3-methylbutyl group, a 2-methylbutyl group, a 1-methylbutyl group, a 1,1-dimethylpropyl group, a 1-ethylpropyl group, a hexyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, a 1,1-dimethylbutyl group, a 2,2-dimethylbutyl group, a 3,3-dimethylbutyl group, a 1,2-dimethylbutyl group, a 1,3-dimethylbutyl group, a 2,3-dimethylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-ethyl-2-methylpropyl group, and a 1-ethyl-1-methylpropyl group.

[0021] X 1 ~X 5 The alkoxy group having 1 to 6 carbon atoms in the formula (I) is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a 2-methylbutyloxy group, a 1-methylbutyloxy group, a tert-butoxy group, a pentyloxy group, a 2-methylpropyloxy group, a 1-methylbutyloxy group, a 1,1-dimethylpropyloxy group, a 1-ethylpropyltyloxy group, a 2-methylpropyloxy group, a hexyloxy group, a 1-methylpentyloxy group, a 2-methylpentyloxy group, a 3-methylpentyloxy group, a 4-methylpentyloxy group, a 1,1-dimethylbutyloxy group, a 2,2-dimethylbutyloxy group, a 3,3-dimethylbutyloxy group, a 1,2-dimethylbutyloxy group, a 1,3-dimethylbutyloxy group, a 2,3-dimethylbutyloxy group, a 1-ethylbutyloxy group, a 2-ethylbutyloxy group, a 1-ethyl-2-methylpropyloxy group, and a 1-ethyl-1-methylpropyloxy group.

[0022] X 1 ~X 5Examples of the alkyloxycarbonyl group having a total of 2 to 7 carbon atoms in the formula (I) include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropyloxycarbonyl group, a butoxycarbonyl group, a 2-methylpropyloxycarbonyl group, a 1-methylpropyloxycarbonyl group, a tert-butoxycarbonyl group, a pentyloxycarbonyl group, a 3-methylbutyloxycarbonyl group, a 1-methylbutyloxycarbonyl group, a 1,1-dimethylpropyloxycarbonyl group, a 1-ethylpropyloxycarbonyl group, a 2-methylpropyloxycarbonyl group, a 2,2-dimethylpropyloxycarbonyl group, a hexyloxycarbonyl group, a 1-methylpentyloxycarbonyl group, a 1,1-dimethylbutyloxycarbonyl group, and a 1-ethylbutyloxycarbonyl group.

[0023] In the above formula (1), X 1 ~X 5 are each independently preferably a hydrogen atom, a methyl group, or an ethyl group, more preferably a hydrogen atom, in that the compound of the general formula (2) can be obtained in high yield.

[0024] In the methylenedianiline compound represented by the above formula (2), X 1 ~X 10 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. 1 ~X 3 At least one of these represents an amino group, and X 6 ~X 8 At least one of these represents an amino group.

[0025] X 1 ~X 10 The alkyl group having 1 to 6 carbon atoms in the formula (1) is not particularly limited, but 1 ~X 5 Examples of the substituents include those exemplified in

[0026] X 1 ~X 10 The alkoxy group having 1 to 6 carbon atoms in the formula (1) is not particularly limited, but 1 ~X 5 Examples of the substituents include those exemplified in

[0027] X 1 ~X 10 The alkyloxycarbonyl group having a total of 2 to 7 carbon atoms in the formula (1) is not particularly limited, but 1 ~X 5 Examples of the substituents include those exemplified in

[0028] The methylenedianiline compound represented by the above formula (2) obtained by the production method of the present invention exists in several isomers depending on the position of the amino group, and these may be produced simultaneously.

[0029] The methylenedianiline represented by the above formula (3) obtained in the production method of the present invention exists in the form of several isomers depending on the position of the amino group; for example, 4,4'-methylenedianiline, 2,4'-methylenedianiline, and 2,2'-methylenedianiline are produced, but these may also be produced simultaneously.

[0030] The catalyst used in the present invention may be a commercially available product or may be synthesized by a commonly known method. The catalyst is not particularly limited, but is preferably one or more selected from the group consisting of alkyl onium salts or basic catalysts, since they can produce the compound represented by formula (2) in high yield.

[0031] The cationic moiety of the alkyl onium salt is not particularly limited, but is preferably a cation selected from the group consisting of ammonium-based cations, imidazolium-based cations, pyrazolium-based cations, pyridinium-based cations, pyrrolidinium-based cations, phosphonium-based cations, and sulfonium-based cations. Among these cations, ammonium-based cations and imidazolium-based cations are preferred because they allow the compound represented by formula (2) to be obtained in high yield.

[0032] The ammonium cation is preferably a quaternary ammonium cation.

[0033] Examples of quaternary ammonium cations include tetramethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, tetraoctylammonium cation, tetranonylammonium cation, tetradecylammonium cation, triethylmethylammonium cation, tripropylmethylammonium cation, tributylmethylammonium cation, tripentylmethylammonium cation, trihexylmethylammonium cation, trioctylmethylammonium cation, tridecylmethylammonium cation, trimethylethylammonium cation, tripropylethylammonium cation, tributylethylammonium cation, tripropylethylammonium cation, tripentylethylammonium cation, trihexylethylammonium cation, trioctylethylammonium cation, tridecylethylammonium cation, tripropylmethyl Ammonium cation, tributylmethylammonium cation, tripentylmethylammonium cation, trihexylmethylammonium cation, trioctylmethylammonium cation, N,N-dimethyl-N-ethyl-N-propylammonium cation, N,N-dimethyl-N-ethyl-N-butylammonium cation, N,N-dimethyl-N-ethyl-N-pentylammonium cation, N,N-dimethyl-N-ethyl-N-hexylammonium cation, N,N-dimethyl-N-ethyl-N-octylammonium cation, N Tetraalkylammonium cations such as N-dimethyl-N-ethyl-N-decylammonium cation, N,N-diethyl-N-methyl-N-propylammonium cation, N,N-diethyl-N-methyl-N-pentylammonium cation, N,N-diethyl-N-methyl-N-hexylammonium cation, N,N-diethyl-N-methyl-N-octylammonium cation, and N,N-diethyl-N-methyl-N-decylammonium cation, as well as 2-hydroxyethyl-trimethyl cation, N-ethyl-N-(2-methoxyethyl)-N,Examples include quaternary ammonium cations with hydroxyalkyl groups or substituents with ether bonds, such as N-dimethylammonium cation, N-ethyl-N-(3-methoxyethyl)-N,N-dimethylammonium cation, and N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium cation.

[0034] Among these quaternary ammonium cations, tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, and 2-hydroxyethyl-trimethyl cation are preferred because they allow the compound of formula (2) to be obtained in high yield.

[0035] Examples of the imidazolium cation include 1,3-dimethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-methyl-3-propylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-methyl-3-pentylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-methyl-3-octylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, imidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1,2-dimethyl-3-pentylimidazolium cation, 1-hexyl-2,3-dimethylimidazolium cation, 1-vinylimidazolium cation, 1-ethyl-3-vinylimidazolium cation, 1-butyl-3-vinylimidazolium cation, 1-allylimidazolium cation, 1-allyl-3-methylimidazolium cation, 1-allyl-3-ethylimidazolium cation, 1-allyl-3-propylimidazolium cation, 1,3-bis(2,4,6-trimethylphenyl)imidazolium, 1,3-bis(2,6-diisopropylphenyl)imidazolium, and the like.

[0036] Examples of the pyrazolium cation include a 1-methylpyrazolium cation, a 3-methylpyrazolium cation, a 1-ethyl-2-methylpyrazolium cation, a 1-methyl-2-propylpyrazolium cation, and a 1-butyl-2-methylpyrazolium cation.

[0037] Examples of the pyridinium cation include a 1-methylpyridinium cation, a 1-ethylpyridinium cation, a 1-propylpyridinium cation, a 1-butylpyridinium cation, a 1-pentylpyridinium cation, a 1-hexylpyridinium cation, a 1-octylpyridinium cation, a 1-ethyl-3-methylpyridinium cation, a 1-propyl-3-methylpyridinium cation, a 1-butyl-3-methylpyridinium cation, a 1-hexyl-3-methylpyridinium cation, a 1-octyl-3-methylpyridinium cation, a 1-decyl-3-methylpyridinium cation, a 1-ethyl-4-methylpyridinium cation, a 1-propyl-4-methylpyridinium cation, a 1-butyl-4-methylpyridinium cation, a 1-hexyl-4-methylpyridinium cation, a 1-octyl-4-methylpyridinium cation, and a 1-decyl-4-methylpyridinium cation.

[0038] Examples of the pyrrolidinium cation include a 1-dimethylpyrrolidinium cation, a 1-ethyl-1-methylpyrrolidinium cation, a 1-methyl-1-propylpyrrolidinium cation, a 1-butyl-1-methylpyrrolidinium cation, a 1-methyl-1-pentylpyrrolidinium cation, a 1-hexyl-1-methylpyrrolidinium cation, a 1-methyl-1-octylpyrrolidinium cation, a 1-decyl-1-methylpyrrolidinium cation, a 1-vinyl-1-methylpyrrolidinium cation, Examples include 1-allyl-1-methylpyrrolidinium cation, 1-diethylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-butyl-1-ethylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-octylpyrrolidinium cation, 1-decyl-1-ethylpyrrolidinium cation, 1-dipropylpyrrolidinium cation, and 1,1-dibutylpyrrolidinium cation.

[0039] Examples of the phosphonium cation include tetramethylphosphonium cation, tetraethylphosphonium cation, tetrapropylphosphonium cation, tetrabutylphosphonium cation, tetrapentylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, tetradecylphosphonium cation, tributylmethylphosphonium cation, tributylethylphosphonium cation, tributylpropylphosphonium cation, tributylhexylphosphonium cation, tributyloctylphosphonium cation, tributyldecylphosphonium cation, and tributyldodecylphosphonium cation.

[0040] Examples of the sulfonium cations include trimethylsulfonium, triethylsulfonium, tripropylsulfonium, tributylsulfonium, tripentylsulfonium, trihexylsulfonium, trioctylsulfonium, and tridecylsulfonium.

[0041] The anion moiety of the alkyl onium salt is not particularly limited, but is preferably an anion selected from the group consisting of a halogen-based anion, a phosphorus-based anion, a sulfur-based anion, a carboxylate-based anion, a bicarbonate ion, etc. Among these anions, a phosphorus-based anion, a carboxylate-based anion, or a bicarbonate ion is preferred because it allows the compound represented by formula (2) to be obtained in high yield.

[0042] The halogen-based anions include fluoride ions, chloride ions, bromide ions, and iodide ions.

[0043] Examples of the phosphorus-based anion include a phosphonate anion, an alkylphosphonate anion, a phosphinate anion, an alkylphosphinate anion, a phosphate anion, an alkylphosphate anion, etc. Among these phosphorus-based anions, a dialkylphosphate anion is preferred, and a dibutylphosphate anion is more preferred, in that the compound represented by formula (2) can be obtained in high yield.

[0044] Examples of the sulfur-based anion include a sulfate anion, a p-toluenesulfonate anion, a methanesulfonate anion, and a trifluoromethanesulfonate anion.

[0045] The carboxylate anion has at least one carboxylate anion (-COO - ), and may contain a functional group having a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of carboxylate anions include, but are not limited to, formate ion, acetate ion, propionate ion, butyrate ion, valerate ion, acrylate ion, oxalate ion, maleate ion, fumarate ion, adipate ion, benzoate ion, salicylate ion, phthalate ion, terephthalic acid, and lactate ion. Among these carboxylate anions, acetate ion and benzoate ion are preferred because they allow the compound represented by formula (2) to be obtained in high yield.

[0046] That is, the alkyl onium salt used in the present invention is preferably one or more selected from the group consisting of tetrabutylammonium acetate, tributylmethylammonium dibutylphosphate, tetrabutylammonium benzoate, 1-butyl-3-methylimidazolium acetate, tetramethylammonium acetate, choline acetate, tetraethylammonium bicarbonate, 1,3-dimethylimidazolium dimethylphosphate, 1,3-bis(2,6-diisopropylphenyl)imidazolium-2-carboxylate, and tetrabutylammonium salicylate.

[0047] The basic catalyst includes inorganic basic compounds and organic basic compounds, and among these basic catalysts, organic basic compounds are preferred.

[0048] Examples of the inorganic basic compound include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal hydrides, alkaline earth metal hydrides, and alkali metal carbonates.

[0049] Examples of the organic basic compound include aliphatic amines, alicyclic amines, aromatic amines, nitrogen-containing heterocyclic compounds, metal alkoxides, metal amides, alkyl metals, etc. Among these organic basic compounds, nitrogen-containing heterocyclic compounds are preferred because they can produce the compound represented by formula (2) in high yield.

[0050] Examples of the nitrogen-containing heterocyclic compound include pyrrole, imidazole, piperidine, pyridine, N,N-dimethyl-4-aminopyridine, pyrimidine, 1,4-diazabicyclooctane, diazabicycloundecene, diazabicyclononene, 1,5,7-triazabicyclo[4,4,0]dec-5-ene, etc. Note that 1,5,7-triazabicyclo[4,4,0]dec-5-ene is preferred because it allows the compound represented by formula (2) to be obtained in good yield.

[0051] The amount of the catalyst used is preferably 0.001 to 10 equivalents, more preferably 0.01 to 1 equivalent, relative to 1 equivalent of the amine compound represented by the above formula (1), in terms of excellent reaction yield.

[0052] The reducing agent used in the present invention may be a commercially available product or may be synthesized by a known method. The reducing agent is not particularly limited, but is preferably one or more selected from the group consisting of a compound having an H-Si bond, a compound having an H-Al bond, and a compound having an H-B bond, in that it can produce the compound represented by formula (2) in high yield.

[0053] Examples of the compound having an H-Si bond, the compound having an H-Al bond, and the compound having an H-B bond include diphenylsilane, phenylsilane, triethylsilane, tris(trimethylsilyl)silane, poly(methylhydrosiloxane), lithium aluminum hydride, diisobutylaluminum hydride, sodium bis(2-methoxyethoxy)aluminum hydride, borane, diborane, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 9-borabicyclo[3.3.1]nonane, lithium tri(1-methylpropyl)borohydride, sodium tri(1-methylpropyl)borohydride, and potassium tri(1-methylpropyl)borohydride. In order to obtain the compound represented by formula (2) in high yield, it is preferable to use one or more compounds selected from the group consisting of compounds having an H-Si bond and compounds having an H-B bond, and it is preferable to use at least one compound selected from the group consisting of diphenylsilane and 9-borabicyclo[3.3.1]nonane in the synthesis.

[0054] The amount of the reducing agent used is preferably 2 to 20 equivalents, more preferably 2.5 to 5 equivalents, relative to 1 equivalent of the amine compound represented by the above formula (1), in terms of excellent reaction yield.

[0055] The acid used in the present invention may be a commercially available product or may be synthesized by a known method. The acid is not particularly limited, but includes inorganic acids such as hydrochloric acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, and phosphoric acid; organic Bronsted acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hydroxybutyric acid, malic acid, salicylic acid, acrylic acid, oxalic acid, maleic acid, fumaric acid, adipic acid, benzoic acid, phthalic acid, terephthalic acid, citric acid, ricinoleic acid, sebacic acid, succinic acid, ferulic acid, and lactic acid; organic Lewis acids such as pentafluorophenylboron and trimethylsilyltriflyl imide; and solid acids such as clay minerals, zeolites, and silica alumina. Among these acids, inorganic acids are preferred because they can produce the compound represented by formula (2) in high yield. Hydrochloric acid, sulfuric acid, or nitric acid is more preferred, and hydrochloric acid is particularly preferred.

[0056] The carbon dioxide used in the present invention can be any that can be obtained by a known method, and is not particularly limited. For example, commercially available carbon dioxide, carbon dioxide separated from a steam-reformed hydrocarbon gas, carbon dioxide separated from a combustion exhaust gas, or carbon dioxide obtained in a lime kiln can be used.

[0057] The purity of the carbon dioxide of the present invention is not particularly limited, but in consideration of ease of reaction, it is preferably 95% or more, more preferably 98% or more.

[0058] The partial pressure of carbon dioxide in the present invention is not particularly limited, but from the viewpoints of reaction rate and energy cost, it is preferably 0.005 to 10 MPa (absolute pressure), more preferably 0.05 to 2 MPa (absolute pressure). Note that the absolute pressure is a pressure where an absolute vacuum is 0 MPa.

[0059] The reaction time of the present invention, i.e., the heat treatment time during which the reaction proceeds, is preferably 0.5 to 48 hours before the addition of acid and 1 to 48 hours after the addition of acid, from the viewpoints of reaction yield and facility operation costs, and more preferably 1 to 12 hours before the addition of acid and 2 to 24 hours after the addition of acid.

[0060] The reaction temperature of the present invention, i.e., the heat treatment temperature when the reaction proceeds, is preferably 15 to 300°C before the addition of acid and 20 to 300°C after the addition of acid, more preferably 20 to 100°C before the addition of acid and 25 to 150°C after the addition of acid, and even more preferably 25 to 80°C before the addition of acid and 30 to 100°C after the addition of acid, from the viewpoints of reaction yield and facility operation costs.

[0061] The reaction method in this embodiment may be any of a flow method (a method in which raw materials are continuously introduced, the reaction is continuously carried out, and the product is continuously recovered), a batch method (a method in which the steps of introducing raw materials, reaction, and product recovery are carried out in order), and a semi-batch method (a method in which some raw materials are introduced, and then other raw materials are continuously introduced, and the product is continuously recovered).

[0062] A solvent may be further used when carrying out the production method of this embodiment. The solvent is not particularly limited, but examples thereof include water, methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, 1-methylpropyl alcohol, 2-methylpropyl alcohol, tert-butyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, tetrahydrofuran, dioxane, diisopropyl ether, cyclopentyl methyl ether, acetonitrile, propylnitrile, benzonitrile, methoxyethanol, dimethoxyethane, propylene glycol dimethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, benzene, toluene, xylene, aniline, and pyridine. These solvents may be used alone or in combination of two or more, as necessary.

[0063] Among these, in terms of excellent reaction yield, one or more selected from the group consisting of tetrahydrofuran, dioxane, diisopropyl ether, cyclopentyl methyl ether, dimethoxyethane, toluene, acetonitrile, aniline, and pyridine are preferred, tetrahydrofuran, dioxane, cyclopentyl methyl ether, toluene, acetonitrile, aniline, and pyridine are more preferred, and tetrahydrofuran and acetonitrile are more preferred.

[0064] The amount of the solvent used is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, and even more preferably 1 to 20 parts by mass, per part by mass of the amine compound represented by the above formula (1) or (2), in terms of excellent reaction yield. [Example]

[0065] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention should not be construed as being limited to these. The compounds used in the examples and comparative examples are abbreviated as follows: Diphenylsilane: Ph2SiH2 9-Borabicyclo[3.3.1]nonane: 9-BBN Tetrabutylammonium acetate: [Bu4N][OAc] Tributylmethylammonium dibutyl phosphate: [Bu3MeN][O(O)P(OBu)2] Tetrabutylammonium benzoate: [Bu4N][OBz] 1-Butyl-3-methylimidazolium acetate: [BMImd][OAc] Tetramethylammonium acetate: [Me4N][OAc] Choline acetate: [Ch][OAc] Tetraethylammonium bicarbonate: [EtN][COOH] 1,3-Dimethylimidazolium dimethyl phosphate: [DMImd][DMP] 1,3-Bis(2,6-diisopropylphenyl)imidazolium-2-carboxylate: IPr-CO2 Tetrabutylammonium salicylate: [Bu4N][SAc] 1,5,7-Triazabicyclo[4,4,0]dec-5-ene: TBD Acetonitrile: CH3CN Tetrahydrofuran: THF The following analytical method was used to identify the methylenedianiline compound.

[0066] 1 H-NMR spectra were measured using ULTRASHIELD PLUS AVANCE III (400 MHz) and ASCEND AVANCE III HD (400 MHz) manufactured by BRUKER. 1 H-NMR was measured using deuterated dimethyl sulfoxide (DMSO-d6) as a measurement solvent and tetramethylsilane (TMS) as an internal standard.

[0067] Mass spectrometry was performed using a Shimadzu GCMS-QP-2010SE.

[0068] Commercially available reagents were used.

[0069] In the following examples, the production rate is 1 The selectivity of 4,4'-methylenedianiline in the following examples is the ratio of 4,4'-methylenedianiline to the total methylenediamines produced, calculated by H-NMR. Therefore, it represents the production rate including not only 4,4'-methylenedianiline but also its isomers, 2,2-methylenedianiline, 2,4-methylenedianiline, etc. In addition, the selectivity of 4,4'-methylenedianiline in the following examples is the ratio of 4,4'-methylenedianiline to the total methylenediamines produced, calculated by the above 1 The values ​​are calculated by H-NMR. Example 1

[0070] [ka]

[0071] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tetrabutylammonium acetate (30.2 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 54%).

[0072] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as an orange oil. 1 The selectivity for 4,4'-methylenedianiline was 67% from H-NMR. 1 H-NMR(400MHz,DMSO-d6)δ(ppm):6.81(brd,J=8.4Hz,4H),6.46(brd,J=8.4Hz,4H),4.80(brs,4H),3.55(s,2H) Example 2

[0073] [ka]

[0074] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tributylmethylammonium dibutylphosphate (41.8 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 58%).

[0075] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as an orange oil. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 71%. Example 3

[0076] [ka]

[0077] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tetrabutylammonium benzoate (36.4 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 52%).

[0078] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as an orange oil. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 72%. Example 4

[0079] [ka]

[0080] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM 1-butyl-3-methylimidazolium acetate (20.6 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50 °C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80 °C for 17 hours. After cooling to 0 °C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production rate of methylenediamine based on aniline: 49%).

[0081] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as a reddish purple oil. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 72%. Example 5

[0082] [ka]

[0083] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 51 mM tetramethylammonium acetate (13.5 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 17 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 59%).

[0084] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as a yellow oil. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 69%. Example 6

[0085] [ka]

[0086] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM choline acetate (13.5 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 17 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 57%).

[0087] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain 4,4'-methylenedianiline as a yellow oil. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 72%. Example 7

[0088] [ka]

[0089] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tetraethylammonium bicarbonate (19.6 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 57%).

[0090] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain a gray solid of 4,4'-methylenedianiline. 1 The selectivity for 4,4'-methylenedianiline was 67% from H-NMR. Example 8

[0091] [ka]

[0092] The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa. 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM 1,3-dimethylimidazolium dimethylphosphate (19.6 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50 °C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80 °C for 17 hours. After cooling to 0 °C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production yield of methylenediamine based on aniline: 38%).

[0093] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain an orange solid of 4,4'-methylenedianiline. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 71%. Example 9

[0094] [ka]

[0095] 1,3-bis(2,6-diisopropylphenyl)imidazolium-2-carboxylate (42.8 mg, 1.00 mmol) was placed in a Pyrex tube and then purged with carbon dioxide to adjust the carbon dioxide partial pressure in the Pyrex tube to 0.1 MPa. 2.0 mL of 500 mM aniline (93.1 mg, 1.00 mmol) in acetonitrile was added. 460 μL (2.49 mmol) of diphenylsilane was added to the reaction solution, and the mixture was stirred at 50 °C in a sealed tube for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80 °C for 17 hours. After cooling to 0 °C, the mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production rate of methylenediamine based on aniline: 42%).

[0096] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain an orange solid of 4,4'-methylenedianiline. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 65%. Example 10

[0097] [ka]

[0098] Tetrabutylammonium salicylate (38.8 mg, 1.00 mmol) was placed in a Pyrex tube, which was then purged with carbon dioxide to adjust the carbon dioxide partial pressure inside the Pyrex tube to 0.1 MPa. 2.0 mL of a 500 mM aniline (93.1 mg, 1.00 mmol) acetonitrile solution was added. 460 μL (2.49 mmol) of diphenylsilane was added to the reaction solution, which was then stirred at 50°C in a sealed tube for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 17 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (production rate of methylenediamine based on aniline: 23%).

[0099] The reaction product was extracted with chloroform (6.0 mL), and the combined organic layers were washed with water (6.0 mL) and saturated brine (6.0 mL), dried over magnesium sulfate, and then concentrated under reduced pressure to obtain an orange solid of 4,4'-methylenedianiline. 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 61%. Example 11

[0100] [ka]

[0101] Tetrabutylammonium acetate (39.0 mg, 0.0259 mmol) and a 0.50 M solution of 9-borabicyclo[3.3.1]nonane in tetrahydrofuran (10.0 mL, 5.00 mmol) were placed in a Schlenk flask, and the atmosphere was replaced with carbon dioxide. The carbon dioxide partial pressure in the Schlenk flask was adjusted to 0.1 MPa, and the mixture was stirred at room temperature for 20 minutes. After replacing the atmosphere with argon, aniline (0.46 mL, 5.04 mmol) was added and the mixture was stirred at room temperature for 24 hours. The reaction mixture was cooled to 0°C, and then 5.00 mL (5.00 mmol) of 1 M hydrochloric acid was added. The mixture was stirred at 80°C for 8 hours. The reaction mixture was cooled to 0°C and neutralized with 5.50 mL (5.50 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The production of 4,4'-methylenedianiline was confirmed by H-NMR (the production rate of methylenediamine based on aniline was 17%). 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 83%. Example 12

[0102] [ka]

[0103] A Schlenk flask was charged with 1,5,7-triazabicyclo[4,4,0]dec-5-ene (38.8 mg, 1.00 mmol) and a 0.50 M tetrahydrofuran solution of 9-borabicyclo[3.3.1]nonane (10.0 mL, 5.00 mmol). The flask was then purged with carbon dioxide, and the carbon dioxide partial pressure in the Schlenk flask was adjusted to 0.1 MPa. The mixture was stirred at room temperature for 20 minutes. After purging the system with argon, aniline (0.46 mL, 5.04 mmol) was added and the mixture was stirred at room temperature for 24 hours. The reaction mixture was cooled to 0°C, and 5.00 mL (5.00 mmol) of 1 M hydrochloric acid was added. The mixture was stirred at 80°C for 8 hours. The reaction mixture was then cooled to 0°C and neutralized with 5.50 mL (5.50 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1The production of 4,4'-methylenedianiline was confirmed by H-NMR (the production rate of methylenediamine based on aniline was 14%). 1 H-NMR revealed that the selectivity for 4,4'-methylenedianiline was 88%. (Comparative Example 1) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tetrabutylammonium acetate (30.2 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 2) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM dibutyl tetrabutylammonium phosphate (41.8 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 3) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM tetrabutylammonium benzoate (36.4 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. Comparative Example 4 The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 51 mM tetramethylammonium acetate (13.5 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 5) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 50 mM choline acetate (13.5 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 6) The Pyrex tube was purged with carbon dioxide to adjust the carbon dioxide partial pressure inside the Pyrex tube to 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and tetraethylammonium bicarbonate (19.6 mg, 0.100 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After allowing the reaction mixture to cool to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, it was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 7) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.1 mg, 1.00 mmol) and 1,3-bis(2,6-diisopropylphenyl)imidazolium-2-carboxylate (42.8 mg, 1.00 mmol) in acetonitrile was added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 8) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a tetrahydrofuran mixture of 500 mM aniline (93.1 mg, 1.00 mmol) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (13.9 mg, 1.00 mmol) was added. The mixture was stirred at 50°C in a sealed tube for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, the atmosphere was purged with argon, and the mixture was stirred at 80°C for 18 hours. After cooling to 0°C, the mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution. 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. Comparative Example 9 The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a 500 mM aniline (93.1 mg, 1.00 mmol) acetonitrile solution and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, 1.00 mL (1.00 mmol) of 1 M hydrochloric acid was added, and the atmosphere was replaced with argon, followed by stirring at 80°C for 18 hours. After cooling to 0°C, the reaction mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution, and then 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 10) A 0.50 M solution of 9-borabicyclo[3.3.1]nonane in tetrahydrofuran (10.0 mL, 5.00 mmol) was placed in a Schlenk flask and then purged with carbon dioxide. The carbon dioxide partial pressure in the Schlenk flask was adjusted to 0.1 MPa and the mixture was stirred at room temperature for 20 minutes. After purging the system with argon, aniline (0.460 mL, 5.04 mmol) was added and the mixture was stirred at room temperature for 24 hours. After cooling the reaction mixture to 0°C, 5.00 mL (5.00 mmol) of 1 M hydrochloric acid was added and the mixture was stirred at 80°C for 8 hours. After purging the atmosphere with argon, 5.00 mL (5.00 mmol) of 1 M hydrochloric acid was added and the mixture was stirred at 80°C for 18 hours. After cooling the reaction mixture to 0°C, the mixture was neutralized with 1.00 mL (1.00 mmol) of 1 M aqueous sodium hydroxide solution and 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR. (Comparative Example 11) The Pyrex tube was purged with carbon dioxide to a carbon dioxide partial pressure of 0.1 MPa, and 2.0 mL of a mixed solution of 500 mM aniline (93.0 mg, 1.00 mmol) and 50 mM tetrabutylammonium acetate (30.1 mg, 0.100 mmol) in acetonitrile and 460 μL (2.49 mmol) of diphenylsilane were added and stirred in a sealed tube at 50°C for 4 hours. After cooling to room temperature, the reaction mixture was replaced with an argon atmosphere and then stirred at 80°C for 17 hours. After cooling, 1,3,5-trimethoxybenzene was used as an internal standard. 1 The formation of 4,4'-methylenedianiline could not be confirmed by 1 H-NMR.

[0104] [Table 1]

[0105] [Table 2]

[0106] [Table 3]

[0107] [Table 4]

[0108] [Table 5]

[0109] [Table 6]

Claims

1. In the presence of a reducing agent and a catalyst, a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure) is reacted with the following formula (1) 【Chemical 1】 [In the above formula, X １ ~X ５ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. １ ~X ３ At least one of these represents a hydrogen atom. to 25 to 300°C, and then an acid is added thereto and the mixture is heated to 25 to 300°C, 【Chemistry 2】 [In the above formula, X １ ~X １０ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an alkyloxycarbonyl group having a total of 2 to 7 carbon atoms, an amino group, or a nitro group. １ ~X ３ At least one of X represents an amino group; ６ ~X ８ At least one of these represents an amino group. A method for producing a methylenedianiline compound represented by the formula:

2. Aniline is heated to 25 to 300°C in the presence of a reducing agent and a catalyst under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure), and then an acid is added and the mixture is heated to 25 to 300°C, whereby a reaction product represented by the following formula (3) is obtained: 【Chemistry 3】 A method for producing methylenedianiline represented by the formula:

3. A method for producing a 4,4'-methylenedianiline compound, comprising heating aniline to 25 to 300°C in the presence of a reducing agent and a catalyst under a carbon dioxide partial pressure of 0.005 to 10 MPa (absolute pressure), adding an acid, and then heating the mixture to 25 to 300°C.

4. The method according to any one of claims 1 to 3, wherein the reducing agent is one or more reducing agents selected from the group consisting of compounds having an H-Si bond and compounds having an H-B bond.

5. 4. The method for producing a methylenedianiline compound according to claim 1, wherein the reducing agent is one or two reducing agents selected from the group consisting of diphenylsilane and 9-borabicyclo[3.3.1]nonane.

6. The method for producing a methylenedianiline compound according to any one of claims 1 to 3, wherein the catalyst is one or more catalysts selected from the group consisting of alkyl onium salts and basic catalysts.

7. The method for producing a methylenedianiline compound according to any one of claims 1 to 3, wherein the anion species of the alkyl onium salt is a phosphate anion, a carboxylate anion, or a bicarbonate ion.

8. 4. The method for producing a methylenedianiline compound according to claim 1, wherein the catalyst is one or more catalysts selected from the group consisting of tributylmethylammonium dibutylphosphate, tetrabutylammonium acetate, tetrabutylammonium benzoate, tetramethylammonium acetate, choline acetate, and tetraethylammonium bicarbonate.

9. 4. The method for producing a methylenedianiline compound according to claim 1, wherein the acid is an inorganic acid.

10. 4. The method for producing a methylenedianiline compound according to claim 1, wherein the acid is hydrochloric acid.

11. The method for producing a methylenedianiline compound according to any one of claims 1 to 3, further comprising using a solvent, and using the solvent in an amount of 0.1 to 100 parts by mass per part by mass of the aniline compound represented by formula (1).

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