JPWO2017169739A1 - Method for producing diamine compound having heterocyclic ring - Google Patents

Abstract

An object of the present invention is to provide a production method for easily and efficiently obtaining a corresponding diamine from a dialdehyde having a heterocyclic ring. In the method for producing a diamine compound having a heterocyclic ring according to the present invention, the dialdehyde compound having a heterocyclic ring, a primary amine and a solvent are mixed in a reaction vessel, and further, a hydrogenation catalyst, ammonia is mixed in the reaction vessel. And a step of performing reductive amination reaction by adding hydrogen.

Description

  The present invention relates to a method for producing a diamine compound having a heterocyclic ring.

  It is known that diamine compounds used as epoxy resin curing agents, lubricants, adhesives, softeners, surfactants, or as raw materials for polyamides and polyurethanes can be synthesized from dialdehydes by reductive amination. ing. For example, in Non-Patent Document 1, 2,5-bisformylfuran (DFF) is reacted with ammonia, hydrogen and a hydrogenation catalyst, and 2,5-bis (aminomethyl) furan (AMF) is obtained by reductive amination. ) Is described.

  Patent Document 1 describes a method for producing an aliphatic or alicyclic diamine by reacting a dialdehyde with a monoamine to form a Schiff base and performing reductive amination in the presence of a catalyst. Patent Document 2 describes a method of obtaining a diamine by supplying a solution obtained by dissolving dialdehyde in a lower alcohol to a reactor for reductive amination.

JP 54-160307 A Japanese Patent Laid-Open No. 10-130210

Ngoc-Thuc Le, Areum Byun, Yohan Han, Kee-In Lee, Hyungrok Kim, “Preparation of 2,5-Bis (Aminomethyl) Furan by Direct Reductive Amination of 2,5-Diformylfuran over Nickel-Raney Catalysts” Green and Sustainable Chemistry, 2015, 5, 115-127

When the present inventor conducted a supplementary examination of Non-Patent Document 1, when DFF and ammonia were mixed, only a polymer was produced, and AMF was not produced. In addition, the method described in Patent Document 1 is uneconomical because an excessive amount of monoamine is required to obtain a Schiff base, and two steps of obtaining the Schiff base and a reductive amination step are necessary. It is. The method of Patent Document 2 is also complicated because it requires two steps of making a solution and a reductive amination step.
Accordingly, an object of the present invention is to provide a production method for easily and efficiently obtaining a corresponding diamine compound from a dialdehyde compound having a heterocyclic ring.

This inventor repeated earnest research in order to solve the said subject. As a result, the inventors have found that the target diamine compound can be easily and efficiently produced simply by mixing a specific compound with a dialdehyde compound having a heterocyclic ring corresponding to the target diamine compound, and the present invention has been completed.
Hereinafter, the present invention will be described.

[1] A method for producing a diamine compound having a heterocyclic ring,
Mixing a dialdehyde compound having a heterocyclic ring, a primary amine and a solvent in a reaction vessel, and further adding a hydrogenation catalyst, ammonia and hydrogen to the reaction vessel to perform a reductive amination reaction. A method characterized by comprising.

  [2] The method according to [1] above, wherein the reductive amination reaction temperature is 50 ° C. or higher and 110 ° C. or lower.

  [3] The method according to [1] or [2] above, wherein the gas phase pressure in the reaction vessel containing hydrogen is 0.5 MPa or more.

  [4] The method according to any one of [1] to [3], wherein the primary amine has 3 to 7 carbon atoms.

  [5] The method according to any one of [1] to [4], wherein the heterocyclic ring contains oxygen and has 4 to 5 carbon atoms.

  [6] The method according to any one of [1] to [5], wherein the solvent is a saturated hydrocarbon alcohol having 1 to 5 carbon atoms.

  According to the method for producing a diamine compound having a heterocyclic ring according to the present invention, the conversion of a raw material dialdehyde compound into a dimer or polymer is suppressed as compared with the conventional production method, and a diamine compound having a heterocyclic ring is easily and efficiently produced. I can get well. Further, it is possible to carry out the dispersion step of the dialdehyde compound in the solvent and the reductive amination step in the same reaction vessel, which is convenient.

1. Dialdehyde Compound Having Heterocycle In the method for producing a diamine compound having a heterocycle according to the present invention (referred to as “diamine compound production method” in the present disclosure), the starting dialdehyde compound is N, A heterocyclic compound containing one or more heteroatoms selected from O, S and P and having two aldehyde groups. The heterocycle may be a saturated heterocycle or an aromatic heterocycle, but is preferably an aromatic heterocycle. Examples of the aromatic heterocycle include six-membered heterocycles such as pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring and triazine ring; nitrogen-containing five-membered heterocycle such as pyrrole ring, imidazole ring and pyrazole ring; furan ring and the like An oxygen-containing five-membered heterocyclic ring; a sulfur-containing five-membered heterocyclic ring such as a thiophene ring; a phosphorus-containing five-membered heterocyclic ring such as a phosphole ring; an oxazole ring, an isoxazole ring, a thiazole ring, and an isothiazole ring. Including five-membered heterocycles. Examples of the saturated heterocycle include a reduced ring of these aromatic heterocycles. The element contained in the ring is preferably N or O, more preferably a heterocyclic compound containing one O, that is, a furan ring.

  The aldehyde group may be bonded to any carbon in the heterocyclic ring, but is preferably bonded to carbons adjacent to N, O, S or P in the ring.

  Specific examples of the dialdehyde compound having a heterocyclic ring include 2,5-dialdehyde furan (DFF), 2,4-dialdehyde furan, 2,3-dialdehyde furan, 3,4-dialdehyde furan, and the like. Furanaldehyde compounds; thiophene dialdehyde compounds such as 2,5-dialdehyde thiophene, 2,4-dialdehyde thiophene, 2,3-dialdehyde thiophene, 3,4-dialdehyde thiophene; 2,5-dialdehyde pyrrole Pyrrole dialdehyde compounds such as 2,4-dialdehyde pyrrole, 2,3-dialdehyde pyrrole, 3,4-dialdehyde pyrrole; 2,5-dialdehyde phosphole, 2,4-dialdehyde phosphole, 2 1,3-dialdehyde phosphor, 3,4-dialdehyde phosphor, etc. Rudehydride compounds; Imidazole dialdehyde compounds such as 2,5-dialdehyde-1H-imidazole and 4,5-dialdehyde-1H-imidazole; 3,4-dialdehyde-1H-pyrazole, 3,5-dialdehyde-1H -Pyrazole dialdehyde compounds such as pyrazole, 4,5-dialdehyde-1H-pyrazole; oxazole dialdehyde compounds such as 2,4-dialdehyde oxazole, 2,5-dialdehyde oxazole, 4,5-dialdehyde oxazole; Thiazole dialdehyde compounds such as 2,4-dialdehyde thiazole, 2,5-dialdehyde thiazole, 4,5-dialdehyde thiazole; 2,5-dialdehyde tetrahydrofuran, 2,4-dialdehyde tetrahydrofuran, 2,3- Dialdehyde tetra Tetrahydrofurandialdehyde compounds such as drofuran and 3,4-dialdehydetetrahydrofuran; pyrrolidines such as 2,5-dialdehydepyrrolidine, 2,4-dialdehydepyrrolidine, 2,3-dialdehydepyrrolidine, 3,4-dialdehydepyrrolidine Dialdehyde compounds; pyrandialdehyde compounds such as 2,6-dialdehydepyran and 2,6-dialdehydetetrahydropyran; pyridinedialdehyde compounds such as 2,6-dialdehydepyridine; 2,6-dialdehydepyrazine and the like Pyrazine dialdehyde compounds; pyrimidine dialdehyde compounds such as 2,6-dialdehyde pyrimidine; piperidine dialdehyde compounds such as 2,6-dialdehyde piperidine; morpholine dialyzes such as 2,6-dialdehyde morpholine Compound; piperazine dialdehyde compounds such as 2,6-dialdehyde piperazine and the like. Among them, those having 4 or 5 carbon atoms constituting the ring are preferable, and a dialdehyde compound in which an aldehyde group is bonded to carbons adjacent to N, O, S or P in the ring is more preferable.

2. Primary amine In the method of Non-Patent Document 1, when DFF and ammonia are mixed, a polymer is formed. How to prevent this polymerization leads to an increase in the yield of AMF. In the present invention, before mixing with ammonia, it was found that polymerization can be suppressed by reacting a primary amine with a dialdehyde compound to prepare a Schiff base. On the other hand, it was also found out that secondary amines and tertiary amines that cannot generate a Schiff base even when reacted with a dialdehyde compound do not have the above-described polymerization inhibiting effect.

  As a reaction process, a Schiff base is rapidly generated from a primary amine and the above-mentioned dialdehyde compound having a heterocyclic ring, and a diimine compound generated by the action of ammonia on the Schiff base, that is, two> C═NH It is presumed that a diamine compound is obtained by reducing a group-containing compound with hydrogen. On the other hand, it is thought that a sequential reaction in which the generated diamine compound acts on the above Schiff base instead of ammonia to form a dimer proceeds, but a more sterically bulky primary amine. And the dialdehyde compound are reacted to prepare a bulky Schiff base, whereby the rate at which the diamine compound produced on the Schiff base acts is slowed, and as a result, the yield of the diamine compound is estimated to be improved.

  Primary amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, isopentylamine, 3-aminopentane, n -Hexylamine, 2-aminohexane, 3-aminohexane, n-heptylamine, 2-aminoheptane, 3-aminoheptane, cyclohexylamine, 2-methylcyclohexylamine, 1,3-bisaminomethylcyclohexane, 2-methyl Examples thereof include chain primary amines such as cyclohexylamine and 2-ethylhexylamine; cyclic primary amines such as 2,5- (bisaminomethyl) furan and 2,5- (bisaminomethyl) tetrahydrofuran.

  Among these, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, isopentylamine, 3-aminopentane, n-hexyl having 3 to 7 carbon atoms Amine, 2-aminohexane, 3-aminohexane, n-heptylamine, 2-aminoheptane, 3-aminoheptane, cyclohexylamine, 1,3-bisaminomethylcyclohexane and 2-methylcyclohexylamine are preferred. Butylamines are more preferable from the viewpoint of easy availability, and sec-butylamine is particularly preferable from the viewpoint of having a bulkiness excellent in the sequential reaction suppressing effect. These primary amines may be used alone or in combination of two or more.

  The primary amine is preferably used in a range of 2.0 to 2.5 mol per mol of the dialdehyde compound having a heterocyclic ring. The primary amine remaining after completion of the reaction can be used again for the reaction.

3. Solvent The solvent used in the present invention is not particularly limited as long as it can appropriately dissolve the dialdehyde compound and the primary amine and is inactive to the reductive amination reaction. These solvents, ether solvents, alcohol solvents, water and the like can be used. Alcohol solvents are particularly preferred, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, Examples include 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol and the like. Among them, a saturated hydrocarbon alcohol having 1 to 5 carbon atoms is preferable, a saturated hydrocarbon alcohol having 1 to 3 carbon atoms is more preferable, and methanol or ethanol is further more preferable in terms of ease of dissolving ammonia. Alcohols can be used alone or in combination of two or more. The alcohol is preferably used so that the concentration of the dialdehyde compound having a heterocyclic ring is 0.5% by mass or more and 20% by mass or less. The concentration is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 4% by mass or more, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

  The reaction temperature of the dialdehyde compound having a heterocyclic ring and the primary amine may be room temperature. Either the dialdehyde compound having a heterocyclic ring or the primary amine may be added first or both may be added simultaneously. The order of addition of the solvent may be determined as appropriate. For example, the solvent may be added to the mixture of the dialdehyde compound and the primary amine, or the solvent may be added in portions.

  The Schiff base is rapidly formed, for example, within 3 minutes when the dialdehyde compound and the primary amine come into contact with each other. The formation of the Schiff base can be confirmed by gas chromatography. As the column for gas chromatography, for example, “DB-1701” manufactured by Agilent Technologies, Inc. can be used, and as the detector, FID (Frame Ionization Detector) can be used.

4). Hydrogenation Catalyst In the method of the present invention, a hydrogenation catalyst, ammonia and hydrogen are added to a mixture of a dialdehyde compound, a primary amine and a solvent. For the hydrogen reduction of a Schiff base formed from a dialdehyde compound and a primary amine, a known catalyst containing Ni, Co, Cu, Pd, Pt, Rh, Ru, etc., which are active components for hydrogenation, is used. Can be used. The form of the catalyst is not particularly limited as long as it contains the active component, and examples thereof include a catalyst formed into a powder, an indeterminate shape, and a fixed shape, a catalyst having the active component supported on a carrier, and the like. The shape of the carrier is not particularly limited, such as powder, granule or pellet. Further, the material of the carrier is not particularly limited, and may be any material that is usually used as a catalyst carrier, such as SiO ₂ , activated carbon, Al ₂ O _{3, and the} like. Moreover, you may use Raney catalysts, such as a Raney cobalt catalyst, a Raney nickel catalyst, a Raney copper catalyst, as a catalyst which does not have a support | carrier, for example.

  Although the usage-amount of a hydrogenation catalyst should just be determined suitably in the range in which a reduction reaction advances favorably, it can be 0.05 g or more and 5 g or less per 100 mL of solvent, for example. When the amount is 0.05 g or more, the reduction reaction can proceed more efficiently. On the other hand, if the amount is 5 g or less, side reactions can be more reliably suppressed. The amount is more preferably 0.1 g or more, still more preferably 0.15 g or more, more preferably 2 g or less, still more preferably 1 g or less, and particularly preferably 0.5 g or less.

5. Ammonia In the method of the present invention, ammonia is allowed to act on a Schiff base formed from a dialdehyde compound and a primary amine to obtain a diimine compound. The amount of ammonia used may be appropriately determined within a range in which the Schiff base is sufficiently converted into a diimine compound. For example, the amount used is 20 times the molar amount or more and 200 times the molar amount or less with respect to the dialdehyde compound used as a raw material. Can be used. If the said amount is 20 times mole amount or more, the target diamine compound will be obtained more reliably. On the other hand, if the amount is 200 times the molar amount or less, waste of ammonia can be suppressed. The amount is more preferably 25 times the molar amount, more preferably 30 times the molar amount and even more preferably 40 times the molar amount. Excess ammonia can be circulated and used again for the reaction.

6). Hydrogen In the method of the present invention, hydrogen is allowed to act on a diimine compound obtained by allowing ammonia to act on a Schiff base formed from a dialdehyde compound and a primary amine to obtain a target diamine compound. The method for adding hydrogen may be appropriately determined. For example, hydrogen may be blown into the mixed solution after adding ammonia, or hydrogen is sealed in a reaction vessel containing the mixed solution so that the reaction proceeds. The mixture may be stirred.

  What is necessary is just to determine the usage-amount of hydrogen suitably, and should just use the stoichiometric amount required in order to obtain a diamine compound at least. Further, for example, hydrogen may be injected so that the pressure of the gas phase in the sealed reaction vessel is 0.5 MPa or more and 30 MPa or less. The pressure is more preferably 0.5 MPa or more, more preferably 0.7 MPa or more, particularly preferably 1.0 MPa or more, more preferably 10 MPa or less, and still more preferably 5 MPa or less. The air pressure can be 0.1 MPa. When hydrogen is injected, hydrogen in the sealed reaction vessel may be replaced with hydrogen, or hydrogen may be added without removing the air. Excess hydrogen can be circulated and used again for the reaction. Moreover, in order to advance reaction more efficiently, it is preferable to stir the liquid mixture in reaction container. The stirring speed can be adjusted to, for example, 200 rpm or more and 1000 rpm or less.

7). Conditions for Reductive Amination Reaction The order of addition of the hydrogenation catalyst, ammonia and hydrogen to the mixture containing the dialdehyde compound, primary amine and solvent is not particularly limited. For example, hydrogen may be introduced into the reaction vessel after adding the hydrogenation catalyst and ammonia to the mixture.

  What is necessary is just to adjust reaction temperature suitably so that a reductive amination reaction may advance favorably, For example, it is preferable to set it as 50 to 110 degreeC. If it is 50 degreeC or more, reductive amination reaction can advance more suitably. On the other hand, if it is 110 degrees C or less, the excessive vaporization of the component which is a liquid at normal temperature can be suppressed. As the said reaction temperature, 60 degreeC or more and 90 degrees C or less are more preferable. The reaction time may be adjusted as appropriate, for example, until the dialdehyde compound or the Schiff base formed from the dialdehyde compound and the primary amine is consumed. Specifically, for example, it can be 10 minutes or more and 10 hours or less.

  The reaction of the present invention can be carried out by arbitrarily selecting a batch format, a semi-batch format, a continuous flow format, or the like. As the reactor, a reactor suitable for the reaction type, for example, a batch reactor, a tubular reactor, or a continuous tank reactor can be arbitrarily selected. In particular, a batch reactor capable of performing a pressure reaction is preferable. What is necessary is just to determine suitably the scale of a reactor, ie, a capacity | capacitance, according to the required scale.

8). Target diamine compound By the above reductive amination reaction, a diamine compound having a heterocyclic ring corresponding to the dialdehyde compound having a heterocyclic ring as a raw material is produced. The obtained diamine compound is preferably purified by a known method such as washing, distillation, crystallization and the like in order to remove by-products.

  Specific examples of the diamine compound produced corresponding to the above dialdehyde compound include 2,5-bis (aminomethyl) furan (AMF), 2,4-bis (aminomethyl) furan, 2,3-bis ( Furanbis (aminomethyl) compounds such as aminomethyl) furan and 3,4-bis (aminomethyl) furan; 2,5-bis (aminomethyl) thiophene, 2,4-bis (aminomethyl) thiophene, 2,3- Thiophene bis (aminomethyl) compounds such as bis (aminomethyl) thiophene and 3,4-bis (aminomethyl) thiophene; 2,5-bis (aminomethyl) pyrrole, 2,4-bis (aminomethyl) pyrrole, 2 Pyrrole bis (aminomethyl) compounds such as 1,3-bis (aminomethyl) pyrrole and 3,4-bis (aminomethyl) pyrrole; Phosphorbis (aminomethyl) compounds such as bis (aminomethyl) phosphole, 2,4-bis (aminomethyl) phosphole, 2,3-bis (aminomethyl) phosphole, 3,4-bis (aminomethyl) phosphole; Imidazole bis (aminomethyl) compounds such as 5-bis (aminomethyl) -1H-imidazole and 4,5-bis (aminomethyl) -1H-imidazole; 3,4-bis (aminomethyl) -1H-pyrazole, 3 , 5-bis (aminomethyl) -1H-pyrazole, pyrazole bis (aminomethyl) compounds such as 4,5-bis (aminomethyl) -1H-pyrazole; 2,4-bis (aminomethyl) oxazole, 2,5 -Oxazols such as bis (aminomethyl) oxazole and 4,5-bis (aminomethyl) oxazole Bis (aminomethyl) compounds; thiazole bis (aminomethyl) compounds such as 2,4-bis (aminomethyl) thiazole, 2,5-bis (aminomethyl) thiazole, 4,5-bis (aminomethyl) thiazole; 2 , 5-bis (aminomethyl) tetrahydrofuran, 2,4-bis (aminomethyl) tetrahydrofuran, 2,3-bis (aminomethyl) tetrahydrofuran, 3,4-bis (aminomethyl) tetrahydrofuran, etc. Compound: Pyrrolidine bis (2,5-bis (aminomethyl) pyrrolidine, 2,4-bis (aminomethyl) pyrrolidine, 2,3-bis (aminomethyl) pyrrolidine, 3,4-bis (aminomethyl) pyrrolidine, etc. Aminomethyl) compound; 2,6-bis (aminomethyl) pyra Pyranbis (aminomethyl) compounds such as 2,6-bis (aminomethyl) tetrahydropyran; tetrahydropyranbis (aminomethyl) compounds such as 2,6-bis (aminomethyl) pyridine; A pyrazine bis (aminomethyl) compound such as 2,6-bis (aminomethyl) pyrazine; a pyrimidine bis (aminomethyl) compound such as 2,6-bis (aminomethyl) pyrimidine; 2,6-bis (aminomethyl) piperidine; Piperidine bis (aminomethyl) compounds such as; morpholine bis (aminomethyl) compounds such as 2,6-bis (aminomethyl) morpholine; piperazine bis (aminomethyl) compounds such as 2,6-bis (aminomethyl) piperazine, etc. Is mentioned.

  The present application claims the benefit of priority based on Japanese Patent Application No. 2016-66110 filed on March 29, 2016. The entire contents of the specification of Japanese Patent Application No. 2016-66110 filed on March 29, 2016 are incorporated herein by reference.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.
The raw material conversion rates and yields in the following examples and comparative examples were determined by the following equations.
Raw material conversion rate (mol%) = [(number of moles of reacted raw material) / (number of moles of added raw material)] × 100
Product yield (mol%) = [(mol number of target product) / (mol number of added raw material)] × 100

Reference Example 1: Polymerization inhibition experiment 20 mL of screw vial was mixed with 0.10 g of 2,5-diformylfuran (DFF) as a dialdehyde having a heterocyclic ring, and n-butylamine as a primary amine was 2 with respect to DFF. A 25-fold molar amount was added, diluted with 10.0 g of methanol, and allowed to stand at room temperature for 1 hour. Furthermore, 10 mL of an ammonia / methanol solution (manufactured by Wako Pure Chemical Industries, 2 mol / L) was added and allowed to stand at room temperature for 3 hours, and then the formation of a polymer was confirmed by appearance. The results are shown in Table 1.

Reference Example 2: Polymerization Suppression Experiment In Reference Example 1, production of a polymer was confirmed in the same manner as in Reference Example 1 except that n-butylamine was changed to sec-butylamine. The results are shown in Table 1.

Reference Example 3: Polymerization Suppression Experiment In Reference Example 1, production of a polymer was confirmed in the same manner as in Reference Example 1 except that n-butylamine was changed to tert-butylamine. The results are shown in Table 1.

Reference Example 4: Polymerization Suppression Experiment In Reference Example 1, production of a polymer was confirmed in the same manner as in Reference Example 1 except that n-butylamine was changed to 1,3-bis (aminomethyl) cyclohexane. The results are shown in Table 1.

Reference Example 5: Polymerization Suppression Experiment In Reference Example 1, production of a polymer was confirmed in the same manner as in Reference Example 1 except that n-butylamine was changed to dibutylamine which is a secondary amine. The results are shown in Table 1.

Reference Example 6: Polymerization Suppression Experiment In Reference Example 1, production of a polymer was confirmed in the same manner as in Reference Example 1 except that n-butylamine was changed to pyrrolidine, which is a secondary amine. The results are shown in Table 1.

Reference Example 7: Polymerization Suppression Experiment In Reference Example 1, the same procedure as in Reference Example 1 was conducted except that n-butylamine was changed to triethylamine, which is a tertiary amine, and the addition amount of triethylamine was changed to 4 mol% with respect to DFF. Thus, formation of a polymer was confirmed. The results are shown in Table 1.

  As a result shown in Table 1, in the case of a primary amine, a polymer was not confirmed. In Reference Examples 3 and 4, a slight color change was observed in the product solution, but the polymer itself could not be confirmed. On the other hand, when a secondary amine and a tertiary amine were used, the solution itself was clearly discolored, and a polymer was confirmed in the solution. Therefore, in the following examples, the reaction was performed using a primary amine.

Example 1: Production of diamine In an autoclave with an internal volume of 100 mL, 0.50 g of 2,5-diformylfuran (DFF) as a dialdehyde having a heterocyclic ring and n-butylamine as a primary amine with respect to DFF A 25-fold molar amount was added, 10.0 g of methanol was added as an alcohol solvent, and the mixture was stirred for 3 minutes. Further, 29.2 g of methanol and 0.15 g of Raney nickel catalyst (manufactured by Kawaken Fine Chemical Co., Ltd., product number NDHT-90) were added and sealed. Thereto was added 9.2 g of liquid ammonia (180-fold molar amount with respect to DFF), and hydrogen was injected to adjust the total pressure to 1.0 MPa. The mixture was stirred at 450 rpm for 1.5 hours under the condition of 75 ° C. After completion of the reaction, the autoclave was ice-cooled, and the content liquid was subjected to 2,5-bis (aminomethyl) furan (AMF) by gas chromatography (column: “DB-1701” manufactured by Agilent Technologies, detector: FID). Quantitative analysis was performed. The results are shown in Table 2.

Example 2: Production of diamine The reaction was conducted in the same manner as in Example 1 except that the primary amine was changed to sec-butylamine in Example 1. The results are shown in Table 2.

Comparative Example 1: Production of diamine The reaction was conducted in the same manner as in Example 1 except that the primary amine was not added. The results are shown in Table 2.

Example 3 Production of Diamine In Example 1, the reaction was performed in the same manner as in Example 1 except that the amount of liquid ammonia to be added was changed to 90-fold molar amount with respect to DFF. The results are shown in Table 2.

Example 4: Production of diamine In Example 3, the reaction was performed in the same manner as in Example 3 except that the primary amine was changed to sec-butylamine. The results are shown in Table 2.

Example 5: Production of diamine The reaction was conducted in the same manner as in Example 1 except that the amount of ammonia to be added was changed to a 26-fold molar amount with respect to DFF. The results are shown in Table 2.

Example 6: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to sec-butylamine. The results are shown in Table 2.

Example 7: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to isopropylamine. The results are shown in Table 2.

Example 8: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to 2-heptylamine. The results are shown in Table 2.

Example 9: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to 2-pentylamine. The results are shown in Table 2.

Example 10: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to cyclohexylamine. The results are shown in Table 2.

Example 11: Production of diamine The reaction was conducted in the same manner as in Example 5 except that in Example 5, the primary amine was changed to 2-methylcyclohexylamine. The results are shown in Table 2.

  As shown in Table 2, although the amount of ammonia with respect to the starting heterocyclic dialdehyde compound tended to affect the yield, it was demonstrated that the method of the present invention can efficiently produce the corresponding diamine compound.

Example 12: Examination of ammonia pressure In an autoclave with an internal volume of 100 mL, 2.50 g of 2,5-diformylfuran (DFF) as a dialdehyde having a heterocyclic ring and sec-butylamine as a primary amine against DFF 2.25-fold molar amount was added, 10.0 g of methanol was added as an alcohol solvent, and the mixture was stirred for 3 minutes. Further, 19.2 g of methanol and 0.66 g of Raney nickel catalyst (manufactured by Kawaken Fine Chemical Co., Ltd., product number NDHT-90) were added and sealed. Thereto, 16.2 g of liquid ammonia (50-fold molar amount with respect to DFF) was added, and hydrogen was injected to adjust the total pressure to 3.0 MPa. The mixture was stirred at 400 rpm for 1.5 hours under the condition of 75 ° C. After completion of the reaction, the autoclave was ice-cooled, and the content liquid was subjected to 2,5-bis (aminomethyl) furan (AMF) by gas chromatography (column: “DB-1701” manufactured by Agilent Technologies, detector: FID). Quantitative analysis was performed. The results are shown in Table 3.

Example 13: Examination of catalyst amount A diamine compound was produced in the same manner as in Example 12 except that the catalyst amount was changed from 0.66 g to 0.32 g. The results are shown in Table 3.

  As shown in Table 3, when the DFF concentration is 5 times that of Example 1 and the amount of ammonia relative to the starting heterocyclic dialdehyde compound is relatively low, the hydrogen pressure is relatively high. It was revealed that the target compound can be produced with high yield. Furthermore, the yield of the target compound could be maintained at 90% or more even when the catalyst amount was reduced to ½.

  According to the production method of the present invention, a corresponding diamine compound can be efficiently produced from a dialdehyde compound having a heterocyclic ring. The obtained diamine compound can be used as a curing agent for an epoxy resin.

Claims (6)

A method for producing a diamine compound having a heterocyclic ring,
Mixing a dialdehyde compound having a heterocyclic ring, a primary amine and a solvent in a reaction vessel, and further adding a hydrogenation catalyst, ammonia and hydrogen to the reaction vessel to perform a reductive amination reaction. A method characterized by comprising.   The method according to claim 1, wherein the reaction temperature of the reductive amination is 50 ° C or higher and 110 ° C or lower.   The method according to claim 1 or 2, wherein the pressure of the gas phase in the reaction vessel containing the hydrogen is 0.5 MPa or more.   The method according to claim 1, wherein the primary amine has 3 to 7 carbon atoms.   The method according to claim 1, wherein the heterocyclic ring contains oxygen and has 4 or more and 5 or less carbon atoms.   The method according to claim 1, wherein the solvent is a saturated hydrocarbon alcohol having 1 to 5 carbon atoms.