WO2023080071A1 - Method for producing 4-hydroxybutyl aldehyde, method for producing gamma butyrolactone, method for producing n-methyl-2-pyrrolidone, and compound - Google Patents

Abstract

The present invention provides a method for producing 4-hydroxybutyl aldehyde, the method comprising a step in which an allyl alcohol is subjected to a hydroformylation reaction together with a carbon monoxide gas and a hydrogen gas in the presence of a rhodium catalyst and a catalyst that contains at least one bidentate phosphine ligand which is selected from among formulae (1) to (3) (wherein Ar represents an optionally substituted aryl group).

Description

Method for producing 4-hydroxybutyraldehyde, method for producing gamma-butyrolactone, method for producing N-methyl-2-pyrrolidone, compound

The present invention is suitable for producing 4-hydroxybutyraldehyde, producing gamma-butyrolactone using the same, producing N-methyl-2-pyrrolidone, and producing 4-hydroxybutyraldehyde by hydroformylation of allyl alcohol. It relates to a ligand compound that constitutes a catalyst used in

　4-Hydroxybutyraldehyde (4-HBA) is a useful compound that can be used as a raw material for various compounds. For example, 1,4-butanediol (1,4-BDO) can be obtained by subjecting 4-HBA to a hydrogen reduction reaction. 1,4-BDO is useful as a raw material for polybutylene terephthalate, urethane resin, and the like. Also, gamma-butyrolactone (GBL) can be produced by dehydrogenating 4-HBA or 1,4-BDO. GBL is widely used industrially as a cleaning agent for electronic materials. It is also possible to derive N-methyl-2-pyrrolidone (NMP) by reacting GBL with monomethylamine. NMP exhibits high solubility in various resins called engineering plastics. For this reason, NMP is widely used industrially, such as for cleaning agents used in the field of electronic materials.

4-HBA can be produced by hydroformylation of allyl alcohol. When an olefinic compound is hydroformylated using a rhodium catalyst and a ligand, the selectivity of linear and branched oxo compounds in the reaction product and the Yields are very different. This also applies to the hydroformylation reaction of allyl alcohol. When allyl alcohol is hydroformylated using a rhodium catalyst and a ligand to produce 4-HBA, 4-HBA having a linear structure is produced, and 3-HBA having a branched structure is produced as a by-product. Hydroxy-2-methylpropionaldehyde (HMPA) is produced, as well as low boiling by-products such as propionaldehyde.

Techniques for hydroformylating an olefinic compound using a rhodium catalyst and a ligand include, for example, the techniques described in Patent Documents 1 to 3 and Non-Patent Document 1.
Patent Document 1 discloses that allyl alcohol is reacted with carbon monoxide and hydrogen in the presence of a rhodium-containing hydroformylation catalyst to form hydroxybutyraldehydes, and the hydroxybutyraldehydes are hydrogenated to produce butanediols. A method for synthesizing is described. Specifically, using hydridocarbonyl tris(triphenylphosphine) rhodium (I) and triphenylphosphine (monodentate ligand) as catalysts, allyl alcohol is reacted with carbon monoxide and hydrogen to obtain 4- It is described that a product containing HBA was produced and that the product was hydrogenated to produce 1,4-BDO.

Patent Document 2 describes a method for hydroformylating allyl alcohol in the presence of a rhodium complex compound and a trisubstituted phosphine. Specifically, it describes the hydroformylation of allyl alcohol using a rhodium complex, triphenylphosphine (monodentate ligand) and 1,4-bis(diphenylphosphino)butane (bidentate ligand). It is

Patent Document 3 describes the use of an optically active organic diphosphine compound and a specific organic diphosphine compound as ligands in a reaction to hydroformylate allyl alcohol in the presence of a rhodium complex catalyst. In Example 6 of Patent Document 3, rhodium-hydride(carbonyl)tri(triphenylphosphine) as a catalyst and trans-4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl- Hydroformylations of allyl alcohols using 1,3-dioxolane (DIOP) and bis(diphenylphosphino)pentane, diphenylmethylphosphine have been described. Table 2 of Patent Document 3 describes that the 4-HBA selectivity in Example 6 was 84.8% and the HMPA selectivity was 13.8%.

Non-Patent Document 1 describes a calculation prediction when using a rhodium complex compound and a phosphine ligand having a xanthene skeleton as catalysts for the hydroformylation reaction. Non-Patent Document 1 uses a simple olefin, 1-octene, as a model compound for hydroformylation. Non-Patent Document 1 describes a prediction that when a phosphine ligand having a xanthene skeleton is used as a catalyst, the production ratio of linear compounds/branched compounds increases.

JP-A-51-29412 JP-A-54-106407 JP-A-6-279345

However, when conventional techniques are used to hydroformylate allyl alcohol to produce 4-hydroxybutyraldehyde (4-HBA), the amount of the target 4-HBA produced and the by-product 3- A greater ratio (4-HBA/HMPA) to the amount of hydroxy-2-methylpropionaldehyde (HMPA) produced is required. HMPA is similar in physical properties to 4-HBA and has a similar boiling point. Therefore, complicated operations are required to separate 4-HBA and HMPA in the reaction product. Therefore, in order to establish an industrial process for producing 4-HBA, in the hydroformylation reaction of allyl alcohol, the amount of HMPA produced as a by-product should be reduced, and the amount of 4-HBA produced in the reaction product should be reduced. It is desirable to increase the ratio (4-HBA/HMPA) to the amount of HMPA produced.

Non-Patent Document 1 describes the prediction that when a phosphine ligand having a xanthene skeleton is used as a catalyst for the hydroformylation reaction of 1-octene, the production ratio of linear compounds/branched compounds will increase. However, the hydroformylation reaction of a compound having a substituent such as allyl alcohol differs greatly from the hydroformylation reaction of a simple olefin such as 1-octene in the linear/branched compound selectivity. Non-Patent Document 1 does not describe predictions about the hydroformylation reaction of allyl alcohol.

The present invention has been made in view of the above circumstances, and a reaction product is obtained in which the amount of HMPA produced is small and the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA) is large. It is an object of the present invention to provide a method for producing 4-HBA that can be obtained.
The present invention also provides a ligand compound that constitutes a catalyst capable of increasing the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA) in the hydroformylation reaction of allyl alcohol. With the goal.

In addition, the present invention provides a high yield of GBL even when the reaction product containing 4-HBA produced in the process of producing 4-HBA is directly used in a reaction for producing gamma-butyrolactone (GBL) without purification. It is an object of the present invention to provide a GBL manufacturing method capable of manufacturing a GBL efficiently.
Another object of the present invention is to provide a method for producing NMP that can efficiently produce N-methyl-2-pyrrolidone (NMP) by including a step of efficiently producing GBL.

That is, the present invention relates to the following matters.
A first aspect of the present invention provides the following method for producing 4-hydroxybutyraldehyde. [1] Hydroformylation of allyl alcohol with carbon monoxide gas and hydrogen gas in the presence of a rhodium catalyst and a catalyst containing at least one bidentate phosphine ligand selected from the following formulas (1) to (3) A method for producing 4-hydroxybutyraldehyde, comprising a step of reacting.

(In formulas (1) to (3), Ar represents an aryl group which may have a substituent.)

The manufacturing method of the first aspect of the present invention preferably includes the features described in [2] to [10] below. Combinations of two or more of these features are also preferred. [2] The method for producing 4-hydroxybutyraldehyde according to [1], wherein Ar in the formulas (1) to (3) is represented by any one of the following formulas (a) to (e).

[3] The hydroformylation reaction in the presence of the rhodium catalyst and the catalyst containing the bidentate phosphine ligand is calculated by the density functional theory, the activation energy of 1,2 insertion into allyl alcohol and 2 , 1-insertion activation energy difference is 4.2 kcal/mol or more.

[4] The bidentate phosphine ligand is represented by the formula (1), and Ar in the formula (1) is represented by any one of the formulas (a), (b), and (c). A method for producing 4-hydroxybutyraldehyde according to any one of [1] to [3].
[5] Any one of [1] to [3], wherein the bidentate phosphine ligand is represented by the formula (2), and Ar in the formula (2) is represented by the formula (a) A process for the preparation of 4-hydroxybutyraldehyde described.
[6] The bidentate phosphine ligand is represented by the formula (3), and Ar in the formula (3) is any one of the formulas (a), (b), (d), and (e) A method for producing 4-hydroxybutyraldehyde according to any one of [1] to [3].

[7] The 4- according to any one of [1] to [6], wherein the amount of the rhodium catalyst used is such that the ratio of rhodium atoms to the allyl alcohol is 0.01 mol% to 5 mol%. A method for producing hydroxybutyraldehyde.
[8] Any one of [1] to [7], wherein the bidentate phosphine ligand is used in an amount of 0.5 mol to 50 mol per 1 mol of rhodium atoms contained in the rhodium catalyst. The method for producing 4-hydroxybutyraldehyde according to .

[9] The pressure of the mixed gas containing carbon monoxide gas and hydrogen gas in the reaction vessel for the hydroformylation reaction is in the range of 0.1 to 10 MPaG (gauge pressure),
According to any one of [1] to [8], wherein the partial pressure ratio of carbon monoxide gas and hydrogen gas (hydrogen gas/carbon monoxide gas) in the reaction vessel is in the range of 1/10 to 10/1. A method for producing 4-hydroxybutyraldehyde.
[10] The 4-hydroxybutyraldehyde according to any one of [1] to [9], wherein the carbon monoxide gas and the hydrogen gas are generated by thermal decomposition of waste plastics and/or biomass. Production method.

A second aspect of the present invention provides the following method for producing gamma-butyrolactone.
[11] A step of producing 4-hydroxybutyraldehyde by the method for producing 4-hydroxybutyraldehyde according to any one of [1] to [10];
A method for producing gamma-butyrolactone, comprising the step of contacting the produced 4-hydroxybutyraldehyde with a copper-containing catalyst.
The manufacturing method of the second aspect of the present invention preferably includes the features described in [11] below.
[12] The method for producing gamma-butyrolactone according to [11], wherein the copper-containing catalyst further contains an oxide of at least one metal element selected from the group consisting of zinc, zirconium and aluminum.

A third aspect of the present invention provides the following method for producing N-methyl-2-pyrrolidone.
[13] A step of producing gamma-butyrolactone by the method for producing gamma-butyrolactone according to [11] or [12];
A method for producing N-methyl-2-pyrrolidone, comprising a step of reacting the produced gamma-butyrolactone with monomethylamine.

A fourth aspect of the present invention provides the following compounds.
[14] A compound represented by the following formula (10).

The above compound can be preferably used as a catalyst in the above production method.

A fourth aspect of the present invention provides the following compounds.
[15] A compound represented by the following formula (8).

The above compound can be preferably used as a catalyst in the above production method.

According to the method for producing 4-HBA of the present invention, the amount of HMPA produced by the hydroformylation reaction is small, and the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA) is large. A product is obtained.

Since the compound of the present invention is a compound represented by the formula (10) or a compound represented by the formula (8), it can be used as a catalyst ligand in the hydroformylation reaction of allyl alcohol with a high yield. 4-HBA can be produced, and a reaction product having a large ratio of 4-HBA to HMPA (4-HBA/HMPA) can be obtained.

The method for producing GBL of the present invention includes a step of producing 4-HBA by the method for producing 4-HBA of the present invention, and a step of contacting the produced 4-HBA with a copper-containing catalyst. Therefore, the reaction product containing 4-HBA produced in the process of producing 4-HBA has a large ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA). Therefore, even if a reaction product containing 4-HBA is directly used in a reaction for producing GBL without purification, GBL can be produced at a high yield and GBL can be produced efficiently.

In addition, the method for producing NMP of the present invention includes a step of producing GBL by the method for producing GBL of the present invention, and a step of reacting the produced GBL with monomethylamine. Therefore, GBL can be efficiently produced, and the produced GBL can be used to efficiently produce NMP, which is an industrially useful compound.

In order to solve the above problems and obtain a reaction product with a large ratio of 4-HBA to HMPA (4-HBA/HMPA), allyl alcohol is mixed with carbon monoxide gas. We also focused on the phosphine ligand used together with the rhodium catalyst in the hydroformylation with hydrogen gas.
As a result, it was found that a rhodium catalyst and at least one bidentate phosphine ligand selected from the above formulas (1) to (3) should be used as the catalyst.

As will be described later, the hydroformylation reaction of allyl alcohol with carbon monoxide gas and hydrogen gas involves the step of inserting allyl alcohol into a rhodium complex catalyst in which carbon monoxide and hydrogen atoms are coordinated to form an intermediate (olefin insertion ) and a step of reductive elimination of the rhodium complex catalyst from the intermediate to form hydroxyaldehyde (reductive elimination step). All of the bidentate phosphine ligands represented by formulas (1) to (3) have a Xantphos skeleton and are electron-rich. Therefore, when the catalyst in which the bidentate phosphine ligand is coordinated to the rhodium complex is used, olefin insertion becomes the rate-limiting step. Therefore, it is presumed that the formation of 4-HBA is promoted and the formation of HMPA is suppressed in the hydroformylation reaction.
The present inventors conducted further studies and found that a large 4-HBA/HMPA reaction product can be obtained by hydroformylating allyl alcohol with carbon monoxide gas and hydrogen gas in the presence of the above catalyst. After confirming this, the present invention was conceived.

Preferred examples of the method for producing 4-hydroxybutyraldehyde, the method for producing gamma-butyrolactone, the method for producing N-methyl-2-pyrrolidone, and the compound provided by the present invention are described in detail below. In addition, this invention is not limited only to embodiment shown below. In the present invention, for example, the number, type, position, amount, ratio, material, configuration, etc. can be added, omitted, replaced, changed, etc. without departing from the gist of the present invention.

[Method for producing 4-hydroxybutyraldehyde]
The method for producing 4-hydroxybutyraldehyde (4-HBA) of the present embodiment comprises a rhodium catalyst and a catalyst containing at least one bidentate phosphine ligand selected from the following formulas (1) to (3). Below, allyl alcohol is hydroformylated with carbon monoxide gas and hydrogen gas.

(In formulas (1) to (3), Ar represents an aryl group which may have a substituent.)

(hydrogen gas, carbon monoxide gas)
In the method for producing 4-HBA of the present embodiment, allyl alcohol is hydroformylated with carbon monoxide gas and hydrogen gas. In this embodiment, the allyl alcohol and the catalyst are added into any selected reaction vessel, such as common or pressure-resistant vessels used in the field. In the present embodiment, it is preferable to supply a gas containing carbon monoxide gas and a gas containing hydrogen gas to a reaction vessel for hydroformylation reaction of allyl alcohol. The gas containing carbon monoxide gas and the gas containing hydrogen gas may be separately supplied to the reaction vessel, or may be supplied to the reaction vessel in the state of a mixed gas of the gas containing carbon monoxide gas and the gas containing hydrogen gas. may be supplied to

The gas containing carbon monoxide gas supplied to the reaction vessel may be only carbon monoxide gas, or may contain nitrogen gas, an inert gas such as argon, etc., in addition to carbon monoxide gas. . The gas containing hydrogen gas to be supplied to the reaction vessel may be hydrogen gas only, or may contain inert gas such as nitrogen gas and argon in addition to hydrogen gas. The gas containing carbon monoxide gas and the gas containing hydrogen gas preferably do not contain oxidizing gases such as air and oxygen.

In this embodiment, the carbon monoxide gas and hydrogen gas used in the hydroformylation reaction of allyl alcohol may be those generated by thermal decomposition of waste plastics and/or biomass.

The pressure of the mixed gas containing carbon monoxide gas and hydrogen gas in the reaction vessel for the hydroformylation reaction is not particularly limited, but is preferably in the range of 0.1 to 10 MPaG (gauge pressure). It is more preferably in the range of 1 to 5.0 MPaG (gauge pressure), more preferably in the range of 0.5 to 2.5 MPaG (gauge pressure). The pressure of the mixed gas in the reaction vessel was consumed by the hydroformylation reaction so as to be maintained within the range of 0.5 to 2.5 MPaG from the start to the end of the hydroformylation reaction. It is particularly preferable to carry out while supplementing with carbon monoxide gas and hydrogen gas.

When the pressure of the mixed gas in the reaction vessel during the hydroformylation reaction is 0.1 MPaG or more, the hydroformylation reaction proceeds easily. The pressure of the mixed gas in the reaction vessel is preferably high in order to promote the hydroformylation reaction. However, in order to increase the pressure of the mixed gas in the reaction vessel to over 10 MPaG during the hydroformylation reaction, it is necessary to use an expensive device. By setting the pressure of the mixed gas to 10 MPaG or less during the hydroformylation reaction, 4-HBA can be produced using an industrially suitable apparatus and method. In the present embodiment, the catalyst promotes the hydroformylation reaction, so even if the pressure of the mixed gas is 10 MPaG or less, a sufficient reaction rate can be obtained and 4-HBA can be produced with a sufficient yield.

The partial pressure ratio of carbon monoxide gas and hydrogen gas (hydrogen gas/carbon monoxide gas) in the reaction vessel in which the hydroformylation reaction is carried out is preferably in the range of 1/10 to 10/1, preferably 1/5 to 5. /1, more preferably 1/2 to 2/1. When the partial pressure ratio (hydrogen gas/carbon monoxide gas) of carbon monoxide gas and hydrogen gas in the reaction vessel during the hydroformylation reaction is in the range of 1/10 to 10/1, the progress of the hydroformylation reaction A sufficient reaction rate is obtained by supplying the necessary hydrogen gas and carbon monoxide gas. When the partial pressure ratio (hydrogen gas/carbon monoxide gas) is 2/1 or less, it is possible to prevent the hydrogen reduction reaction from proceeding and lowering the yield of 4-HBA.

(rhodium catalyst)
As the rhodium catalyst used in the method for producing 4-HBA of the present embodiment, one that can be used as an olefin hydroformylation catalyst can be used. Only one rhodium catalyst may be used, or two or more rhodium catalysts may be used.

Specific examples of rhodium catalysts include rhodium oxides such as RhO, Rh ₂ O ₃ and RhO ₂ , rhodium salts such as rhodium nitrate, rhodium sulfate, rhodium chloride, rhodium bromide, rhodium iodide and rhodium acetate, and Rhodium complexes such as acetylacetonatodicarbonylrhodium, acetylacetonatocarbonyl(triphenylphosphine)rhodium, hydridocarbonyltris(triphenylphosphine)rhodium(I), and _Rh4 (CO) ₁₂ , _Rh6 (CO) ₁₆ , etc. and a rhodium carbonyl cluster of. Among these rhodium catalysts, rhodium complexes are preferred, and hydridocarbonyltris(triphenylphosphine)rhodium (I) is particularly preferred, in terms of catalytic activity, solubility in solvents, and ease of handling as a catalyst.

The amount of the rhodium catalyst used is not particularly limited, but it is preferably an amount such that the ratio of rhodium atoms is 0.01 mol% to 5 mol%, and the amount is 0.05 mol% to 2 mol%, relative to allyl alcohol. is more preferable, and an amount of 0.1 mol % to 1 mol % is even more preferable. Sufficient hydroformylation activity can be obtained when the proportion of rhodium atoms is 0.01 mol % or more. Further, when the proportion of rhodium atoms is 5 mol % or less, it is economical because loss during recovery of the rhodium catalyst can be suppressed.

(bidentate phosphine ligand)
The bidentate phosphine ligand used in the method for producing 4-HBA of the present embodiment is at least one selected from the above formulas (1) to (3). Only one type of bidentate phosphine ligand may be used, or two or more types may be used.

All of the bidentate phosphine ligands represented by formulas (1) to (3) have an Xantphos skeleton, and when these bidentate phosphine ligands are used, in the hydroformylation reaction of allyl alcohol Olefin insertion becomes the rate limiting step. Although the details are not clear, this is presumed to have a great effect on the selectivity between 4-HBA and HMPA in the hydroformylation reaction of allyl alcohol. As a result, it is presumed that the production of 4-HBA is promoted and the production of HMPA is suppressed, the selectivity of 4-HBA is increased, and a reaction product having a large ratio of 4-HBA/HMPA is obtained. The value (ratio) of 4-HBA/HMPA is arbitrarily selected as required. For example, it may be 10.0 or more, 11.0 or more, 12.0 or more, 13.0 or more, 14.0 or more, or 15.0 or more, but it is not limited to these examples.

In contrast, for example, trans-4,5-bis(diphenylphosphinomethyl)-2,2, a bidentate phosphine ligand without an Xantphos skeleton conventionally used in hydroformylation reactions of allyl alcohol When -dimethyl-1,3-dioxolane (DIOP) is used, the reductive elimination from the rhodium catalyst in the hydroformylation reaction becomes the rate-limiting step.

Ar in formulas (1) to (3) is an aryl group which may have a substituent. The aryl group which may have a substituent is not particularly limited as long as it is an aromatic hydrocarbon group. Therefore, the aryl group which may have a substituent may be a monocyclic aromatic group or a polycyclic aromatic group.
The aryl groups, which may have four substituents, contained in one molecule of the bidentate phosphine ligand may be different, or may be partially or wholly the same, which facilitates production. Therefore, it is preferable that all are the same.

An optionally substituted aryl group may have one substituent or two or more substituents. When an aryl group has two or more substituents, all those substituents may be different, or some or all of them may be the same.
When the aryl group which may have a substituent has a substituent, the bonding position of the substituent in the aryl group is not particularly limited.

Substituents possessed by the optionally substituted aryl group include, for example, linear or branched alkyl groups, dialkylamino groups, cyano groups, nitro groups, amino groups, hydroxy groups, halogenated alkyl groups, and the like. is mentioned. As a substituent, a linear or branched alkyl group and/or a dialkylamino group function as an electron-donating group and the stability of the aryl group, which may have a substituent, is improved. Especially preferred.

The linear or branched alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms. Examples of linear or branched alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group. and a methyl group is preferred in terms of ease of production.

The dialkylamino group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms. Specific examples of the dialkylamino group include a dimethylamino group, a diethylamino group, a methylethylamino group, and the like, and the dimethylamino group is preferred in terms of ease of production.

Specifically, the aryl group which may have a substituent is preferably a phenyl group or a phenyl group having a substituent.
Ar in the formulas (1) to (3) gives a reaction product with a large ratio of the amount of 4-HBA to the amount of HMPA (4-HBA/HMPA), so the following formulas (a) to (e) is more preferred, and formula (b) is even more preferred because 4-HBA can be produced in high yield. "---" in each formula means a bond with the P atom.

When the bidentate phosphine ligand is represented by formula (1), a larger reaction product of 4-HBA/HMPA is obtained, so Ar in formula (1) is represented by formula (a ), (b), or (c). In particular, 4-HBA can be produced in a high yield, and a reaction product with a large ratio of 4-HBA/HMPA can be obtained. It is preferably a compound that

When the bidentate phosphine ligand is represented by formula (2), a larger reaction product of 4-HBA/HMPA is obtained, so Ar in formula (2) is represented by formula (a ) is more preferred.
When the bidentate phosphine ligand is represented by formula (3), a larger reaction product of 4-HBA/HMPA is obtained, so Ar in formula (3) is represented by formula (a ), (b), (d), or (e). In particular, since 4-HBA can be produced in high yield, a compound in which Ar in formula (3) is formula (a), or the following formula (8) in which Ar in formula (3) is formula (b) It is preferably a compound represented by.

The bidentate phosphine ligand is the difference in activation energy between 1,2 insertion and 2,1 insertion in the hydroformylation reaction calculated by the density functional theory described later (hereinafter simply referred to as "activation energy difference" is preferably 4.2 kcal/mol or more, more preferably 4.5 kcal/mol or more, even more preferably 5.0 kcal/mol or more, Larger is better. When the bidentate phosphine ligand has a difference in activation energy of 4.2 kcal/mol or more, the selectivity of 4-HBA becomes higher, and the amount of 4-HBA produced and the amount of HMPA produced increase. A reaction product with a greater ratio of (4-HBA/HMPA) is obtained. Therefore, the yield and selectivity of 4-HBA in the method for producing 4-HBA of the present embodiment can be further increased.

[Difference in activation energy between 1,2 insertion and 2,1 insertion]
When allyl alcohol is subjected to a hydroformylation reaction using the production method of the present embodiment, 4-HBA, which is the target product, is produced, and HMPA, which is a by-product, is produced. 4-HBA is a linear compound with a linear structure. HMPA is a branched compound with a branched structure. When a rhodium catalyst having an Rh—H bond is used, the 1,2-insertion in the hydroformylation reaction of allyl alcohol means that, as shown in the following reaction formula, allyl alcohol (olefin) is Rh- It is a reaction pathway in which 4-HBA is produced by inserting between H bonds to form a linear rhodium complex. 2,1-insertion is a reaction in which allyl alcohol is inserted between the Rh—H bonds of a rhodium catalyst to form a branched rhodium complex, and as shown in the reaction formula below, it is a reaction pathway in which HMPA is produced. be.

The difference between the activation energy of 1,2-insertion and the activation energy of 2,1-insertion (2,1-insertion - 1,2-insertion) is the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4- There is a correlation with HBA/HMPA). Specifically, 4-HBA/HMPA tends to increase as the activation energy for 1,2 insertion is smaller and the activation energy for 2,1 insertion is larger. Therefore, 4-HBA/HMPA can be predicted by obtaining the difference in activation energy between 1,2-insertion and 2,1-insertion in the hydroformylation reaction of allyl alcohol calculated by the density functional theory. However, the difference in activation energy is a value that does not consider side reactions associated with isomerization of allyl alcohol. The ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA) may be slightly affected by side reactions associated with isomerization of allyl alcohol.

Depending on the type of bidentate phosphine ligand, the activation energy for 1,2 insertion and the activation energy for 2,1 insertion in the hydroformylation reaction of allyl alcohol when a rhodium catalyst having an Rh—H bond is used is Change. Therefore, the difference in activation energy can be used as an index for selecting the bidentate phosphine ligand used in the hydroformylation reaction of allyl alcohol.

The bidentate phosphine ligand is used in an amount of 0.5 mol to 50 mol, preferably 1.5 mol to 20 mol, more preferably 2.5 mol to 50 mol, per 1 mol of rhodium atoms contained in the rhodium catalyst. It ranges from 0 mol to 10 mol. When the amount of the bidentate phosphine ligand to be used is 50 mol or less, a sufficient effect of improving the reaction rate of the hydroformylation reaction can be obtained, which is economically advantageous. When the amount of the bidentate phosphine ligand used is 0.5 mol or more, the selectivity of 4-HBA becomes higher, and the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA ) is obtained.

The bidentate phosphine ligand used in the method for producing 4-HBA of the present embodiment can be produced by appropriately combining known methods.
A bidentate phosphine ligand may be used by purchasing a commercially available product.

(solvent)
In the method for producing 4-HBA of the present embodiment, it is preferable to carry out the hydroformylation reaction of allyl alcohol in a solvent. As the solvent, it is preferable to use a solvent that is inert to the starting material, allyl alcohol, and the reaction product. Specifically, as solvents, tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, n-propyl acetate, n-butyl acetate, n-heptane, acetonitrile, benzene, toluene, xylene, N-methyl-2 -pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide and the like. Among these solvents, aromatic compounds such as benzene, toluene, and xylene are particularly preferable because they are highly separable from water. By using these aromatic compounds as a solvent, water is added to the reaction solution after the hydroformylation reaction of allyl alcohol, and the desired 4-HBA is added to the aqueous layer side. can efficiently extract reaction products containing

The amount of the solvent to be used is 1 to 1 by weight with respect to allyl alcohol, since the separation of the organic layer and the aqueous layer is improved in the operation of adding water to the reaction solution after the hydroformylation reaction and separating the layers. It is preferably 50 times, more preferably 5 to 30 times, even more preferably 5 to 20 times.

(Reaction conditions)
The reaction temperature in the hydroformylation reaction of allyl alcohol is preferably 40 to 100°C, more preferably 40 to 80°C, even more preferably 50 to 70°C. When the reaction temperature is 40° C. or higher, 4-HBA can be efficiently produced without extremely slowing down the reaction rate. Further, when the reaction temperature is 100° C. or less, the selectivity of 4-HBA is not lowered due to excessively high reaction rate, and the stability of the catalyst is not impaired.

If the reaction time in the hydroformylation reaction of allyl alcohol is too short, the conversion of allyl alcohol may become insufficient. Also, if the reaction time is too long, the reaction product may decompose. Therefore, the reaction time is preferably 0.5 to 10 hours, more preferably 0.5 to 5 hours, even more preferably 1 to 3 hours. A reaction time of 0.5 to 10 hours ensures a high yield and good productivity.
As the reactor used in the method for producing 4-HBA of the present embodiment, for example, a pressure-resistant reactor such as an autoclave can be used.
4-HBA obtained in the hydroformylation step may be further purified. Alternatively, it may be stored as it is or used as a raw material for other production without purification. For example, the obtained 4-HBA may be used as it is in a method for producing gamma-butyrolactone and the like without being purified.
High yield may mean, for example, 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 97% or more, but is limited to these examples only. not.

[Method for producing gamma-butyrolactone]
The method for producing gamma-butyrolactone (GBL) of the present embodiment includes the steps of producing 4-HBA by the method for producing 4-HBA of the present embodiment, and the steps of contacting the produced 4-HBA with a copper-containing catalyst. including. In the method for producing GBL of the present embodiment, 4-HBA is brought into contact with a copper-containing catalyst, and 4-HBA is dehydrogenated to produce GBL.

The method for producing GBL of the present embodiment includes a step of producing 4-HBA by the method for producing 4-HBA of the present embodiment. Therefore, the reaction product containing 4-HBA produced in the process of producing 4-HBA has a low HMPA content, and the ratio of the amount of 4-HBA produced to the amount of HMPA produced (4-HBA/HMPA) is large. Therefore, even if a reaction product containing 4-HBA is directly used in a reaction for producing GBL without purification, GBL can be produced at a high yield and GBL can be produced efficiently. High yield may mean, for example, 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 97% or more, but is limited to these examples only. not.

Further, in the method for producing GBL of the present embodiment, highly pure 4-HBA obtained by further purifying the reaction product containing 4-HBA produced by the method for producing 4-HBA of the present embodiment, It may be used in reactions to produce GBL. In this case, the reaction product containing 4-HBA produced in the step of producing 4-HBA has a large ratio of 4-HBA/HMPA, so purification is easy. As a method for purifying the reaction product containing 4-HBA, for example, a known method such as a method of separating each component by distillation utilizing the boiling point difference of each component contained in the reaction product can be used. .

(Catalyst containing copper)
In this embodiment, the copper-containing catalyst that is contacted with 4-HBA contains copper as the active metal. The copper-containing catalyst preferably further contains an oxide of at least one metal element selected from the group consisting of zinc, zirconium and aluminum. The copper-containing catalyst may further contain other metal oxides in addition to copper and oxides of at least one metal element selected from the group consisting of zinc, zirconium and aluminum.

As for other metal oxides, chromium oxides are preferable. Dehydrogenation reaction of 4-HBA when the copper-containing catalyst contains an oxide of at least one metal element selected from the group consisting of zinc, zirconium and aluminum, and an oxide of chromium in addition to metallic copper. can be expected to activate the reaction that produces GBL by lowering the activation barrier of In addition, since the copper-containing catalyst contains chromium oxide, it suppresses the side reaction that produces 1,4-butanediol produced by the reduction of 4-HBA and other impurities, and improves the selectivity of GBL. An improvement effect can be expected. For these reasons, the copper-containing catalyst used in the dehydrogenation reaction of 4-HBA more preferably contains chromium oxide.

The copper-containing catalyst preferably consists of copper, at least one selected from the group consisting of zinc, zirconium and aluminum, chromium, and oxygen.
Specific examples of copper-containing catalysts containing chromium oxides include catalysts containing zinc and chromium oxides and metallic copper (CuZnCrOx); catalysts containing zirconium and chromium oxides and metallic copper (CuZrCrOx); catalysts containing oxides of aluminum and chromium and copper metal (CuAlCrOx); catalysts containing oxides of zinc, zirconium and chromium and copper metal (CuZnZrCrOx); oxidation of zinc, aluminum and chromium oxides of zirconium, aluminum and chromium, and copper metal (CuZrAlCrOx); oxides of zinc, zirconium, aluminum, and chromium, and copper metal catalyst (CuZnZrAlCrOx) and the like. In the above formula, x representing the proportion of oxygen atoms is an arbitrarily selected number. x in the formula may be, for example, 0.025 to 13.5, 0.045 to 10.5, 0.065 to 6.5, or 0.085 ~2.25.

The content of each metal of copper, zinc, zirconium, aluminum, and chromium in the catalyst containing copper can be arbitrarily selected. Since the content of each metal in the catalyst containing copper can further promote the reaction that produces GBL, it is 1.0 mol or less of zinc, 5.0 mol or less of zirconium, and 5.0 mol or less of aluminum per 1 mol of copper. mol or less, preferably 0.5 mol or less of chromium.

Zinc in the copper-containing catalyst is preferably 1.0 mol or less, more preferably 0.005 to 0.4 mol, and 0.01 to 0.3 mol, relative to 1 mol of copper. is more preferably 0.01 to 0.2 mol, and particularly preferably 0.05 to 0.1 mol.

Zirconium in the copper-containing catalyst is preferably 5.0 mol or less, more preferably 0.01 to 1.0 mol, and 0.05 to 0.4 mol, per 1 mol of copper. is more preferably 0.05 to 0.3 mol, and particularly preferably 0.1 to 0.2 mol.

Aluminum in the catalyst containing copper is preferably 5.0 mol or less, more preferably 0.01 to 3.0 mol, and 0.05 to 1.0 mol, per 1 mol of copper. is more preferably 0.1 to 0.8 mol, and particularly preferably 0.2 to 0.6 mol.

The amount of chromium in the catalyst containing copper is preferably 0.5 mol or less, more preferably 0.01 to 0.4 mol, more preferably 0.03 to 0.3 mol, per 1 mol of copper. more preferably 0.05 to 0.2 mol, more preferably 0.07 to 0.15 mol.

As a method for producing a copper-containing catalyst, a known method such as a coprecipitation method, a pore filling method, or a hydrothermal synthesis method can be used.

(Step of producing gamma-butyrolactone)
In the step of producing GBL by contacting 4-HBA with a copper-containing catalyst in the method for producing GBL of the present embodiment (hereinafter sometimes referred to as “GBL production step”), an aqueous solution of 4-HBA is It is preferable to vaporize and bring the vaporized 4-HBA into contact with the copper-containing catalyst. As the aqueous solution of 4-HBA, it is preferable to use an aqueous solution containing 1 to 30% by mass of 4-HBA, more preferably 5 to 25% by mass, still more preferably 10 to 20% by mass. By vaporizing an aqueous solution containing 1 to 30% by mass of 4-HBA and bringing the 4-HBA into contact with a copper-containing catalyst in the vapor phase, the reaction to generate GBL can be further accelerated. This step may include a step of preparing or adjusting an aqueous solution of 4-HBA having a preferred concentration as described above.

In the GBL production process, when an aqueous solution containing 30% by mass or more of 4-HBA is used as the aqueous solution of 4-HBA, it is preferable to adjust the liquid hourly space velocity (LHSV) in terms of raw materials. For example, when an aqueous solution containing 30 to 50% by mass of 4-HBA is used, the liquid hourly space velocity (LHSV) in terms of raw material is preferably 1.6 hr ^-1 or less in order to maintain the yield of GBL. It is more preferable to make it 0.4 hr ⁻¹ or less. The lower limit of the liquid hourly space velocity (LHSV) can be selected as required, and may be, for example, 0.1 hr ⁻¹ or more, but is not limited to this.

In the GBL production process, it is preferable to bring 4-HBA and a copper-containing catalyst into contact in the gas phase at a reaction temperature of over 200°C. When the reaction temperature is higher than 200° C., 4-HBA exists in the gaseous phase during the reaction, promoting the reaction to produce GBL and producing GBL at a higher yield. The reaction temperature is preferably 400° C. or lower because the safety of the reaction to generate GBL is further enhanced. The reaction temperature is more preferably 210 to 370°C, even more preferably 230 to 360°C, and particularly preferably 260 to 350°C.

The GBL production process can be performed, for example, using a fixed-bed gas-phase reactor having a reaction vessel filled with a copper-containing catalyst.
GBL obtained in the GBL manufacturing process may be purified by a general method such as distillation under reduced pressure. GBL obtained in the GBL production process can be preferably used as a raw material for N-methyl-2-pyrrolidone.

[Method for producing N-methyl-2-pyrrolidone]
The method for producing N-methyl-2-pyrrolidone (NMP) of the present embodiment includes a step of producing GBL by the method for producing GBL of the present embodiment, and a step of reacting the produced GBL with monomethylamine. .

The step of reacting GBL and monomethylamine in the method for producing NMP of the present embodiment is, for example, a step of producing NMP by putting GBL, monomethylamine, and a solvent into a reaction vessel and causing a liquid phase reaction. be able to.
As the reaction vessel, a reaction vessel made of stainless steel can be preferably used.
Alcohols or water can be used as the solvent, preferably water.

In the step of reacting GBL with monomethylamine, the molar ratio of monomethylamine to 1 mol of GBL used as a raw material is preferably in the range of 1 to 10, more preferably in the range of 1 to 5, and even more preferably. It ranges from 1 to 1.5. When the molar ratio of monomethylamine to 1 mol of GBL is in the range of 1 to 10, NMP can be produced in high yield.

The reaction between GBL and monomethylamine may be carried out in the air or in an inert gas atmosphere such as a nitrogen gas atmosphere or an argon atmosphere, preferably in a nitrogen gas atmosphere.
The reaction between GBL and monomethylamine is preferably carried out at a reaction temperature of 100 to 400°C, more preferably 150 to 350°C, still more preferably 200 to 300°C. When the reaction temperature is 100 to 400° C., the reaction to produce NMP is promoted, and NMP can be produced in a higher yield.
The reaction time of GBL and monomethylamine is preferably 0.1 to 10 hours, more preferably 0.5 to 7 hours, still more preferably 1 to 5 hours. A reaction time of 0.1 to 10 hours ensures a high yield and good productivity.
High yield may mean, for example, 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 97% or more, but is limited to these examples only. not.

The reaction solution containing NMP produced in the step of reacting GBL and monomethylamine may be purified by a general method such as distillation under reduced pressure.
The NMP manufacturing method of this embodiment includes a step of manufacturing a GBL by the GBL manufacturing method of this embodiment. Therefore, GBL can be efficiently produced, and the produced GBL can be used to efficiently produce NMP, which is an industrially useful compound.

The present invention will be described in more detail below with reference to examples and comparative examples. In addition, the present invention is not limited only to the following examples.

[Analysis method]
Conversion rate and yield of the compound produced in the method for producing 4-hydroxybutyraldehyde (4-HBA), the method for producing gamma-butyrolactone (GBL), and the method for producing N-methyl-2-pyrrolidone (NMP) shown below asked for Specifically, under the following analysis conditions, using high performance liquid chromatography (HPLC), the raw materials and reaction products in the reaction solution are analyzed, quantified using the absolute calibration curve method, and the results are used. Each value was calculated by

<Analysis conditions: 4-HBA production method>
Column: Shodex SUGAR SH-1011 (manufactured by Showa Denko K.K.)
Column size: 8.0mm x 300mm
Column temperature: 40°C
Eluent: 0.01 N sulfuric acid aqueous solution Flow rate of eluent: 0.5 ml/min
Detector: UV (ultraviolet) 210 nm, RI (differential refractive index)

<Analysis conditions: GBL manufacturing method, NMP manufacturing method>
Column: Shodex RSpak KS-801 (manufactured by Showa Denko KK)
Column size: 8.0mm x 250mm
Column temperature: 40°C
Eluent: pure water Eluent flow rate: 0.6 ml/min
Detector: UV (ultraviolet) 210 nm, RI (differential refractive index)

[Method for producing 4-hydroxybutyraldehyde (4-HBA)]
(Example 1)
In a stainless steel autoclave reaction vessel with a capacity of 100 mL, 1.89 g of allyl alcohol (AAL), 30 g of toluene as a solvent, and hydridocarbonyl tris(triphenylphosphine) rhodium (I) (RhH(CO) (PPh ₃ ) ₃ (manufactured by Tokyo Chemical Industry Co., Ltd.)) 0.0536 g (0.18 mol % with respect to allyl alcohol), and 4,6-bis(diphenylphosphino)phenoxy which is a bidentate phosphine ligand 0.129 g of sardine (Nixantphos, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst) was added.

Then, the reaction vessel is filled with a mixed gas of carbon monoxide gas and hydrogen gas and the pressure is 2.0 MPaG (gauge pressure) (carbon monoxide gas partial pressure 1.0 MPaG (gauge pressure), hydrogen gas partial pressure The pressure was adjusted to 1.0 MPaG (gauge pressure), and the reaction was carried out at a reaction temperature of 65°C for 3 hours while stirring the inside of the reaction vessel. After the reaction, 30 g of water was added to the reaction solution for extraction, and a liquid separation operation was performed to recover the aqueous layer, thereby obtaining an aqueous solution containing a reaction product containing 4-HBA.

(Example 2)
<Production of bidentate phosphine ligand>
4,6-Bis(diphenylphosphino)phenoxazine (1 g, 1.81 mmol) and 20 mL of dehydrated tetrahydrofuran were placed in a 200-mL two-necked flask purged with nitrogen, and 0.1 g of sodium hydride was added. It was refluxed for 1 hour at a temperature of °C. Further, a mixed solution of 0.62 g of benzyl chloride and 5 mL of tetrahydrofuran was added, and the mixture was refluxed at a temperature of 70° C. for 16 hours for reaction. After that, the temperature of the reaction solution was lowered to room temperature, and benzene and an aqueous sodium chloride solution were added to separate the solution. After the organic layer was washed with water and dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was washed with hexane. After that, by recrystallizing with dichloromethane and ethanol, 0.9 g of the compound represented by the following formula (4) was obtained as a pale gray solid. The yield of the compound represented by formula (4) was 78%.

¹ H-NMR and ³¹ P-NMR measurements were performed on the obtained compound represented by formula (4), and the structure was identified by the following results.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 7.33 (m, 5H), 7.24 (m, 20H), 6.59 (t, J = 9.6Hz, 2H), 6.31 (dd, J = 7.9, 1.3 Hz, 2H), 6.04 (dq, J = 7.8, 1.6, 1.6 Hz, 2H), 4.80 (s, 2H)
³¹ P-NMR (162 MHz, CDCl ₃ ): δ -18.4

As a bidentate phosphine ligand, 0.1496 g of a bidentate phosphine ligand represented by formula (4) (4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst) was used, and the reaction time was 2 hours. An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in Example 1, except that

(Example 3)
<Production of bidentate phosphine ligand>
Cesium carbonate (18.07 g, 55.5 mol) was introduced into a two-necked flask with a capacity of 200 mL that was purged with nitrogen, dried in vacuo at a temperature of 150° C. for 2 hours, and then palladium (II) acetate (0.15 g , 0.70 mmol), triphenylphosphine (0.73 g, 2.77 mmol), 1-naphthol (2 g, 13.87 mmol), 1,2-dibromobenzene (2 mL, 16.6 mmol), N, 80 mL of N-dimethylformamide was added, and the mixture was refluxed at a temperature of 140° C. for 72 hours for reaction. Thereafter, the temperature of the reaction solution was lowered to room temperature, and diethyl ether and water were added to separate the solution. After the organic layer was washed with water and dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by chromatography. As a result, 2.5 g of a compound represented by the following formula (5) was obtained as a white solid. The yield of the compound represented by formula (5) was 83%.

In a nitrogen-substituted three-necked flask with a capacity of 200 mL, the compound represented by the formula (5) (2 g, 9.13 mmol) and N,N,N',N'-tetramethylethylenediamine (4.11 ml, 27.49 mmol) ) and 100 mL of dehydrated diethyl ether were charged, and an n-butyllithium solution (2.5 M hexane solution, 11 mL, 27.49 mmol) was added dropwise over 20 minutes while maintaining the temperature at 0°C. After completion of dropping, the mixture was stirred at room temperature for 16 hours. Further, chlorodiphenylphosphine (4.93 ml, 27.4 mmol) was added while maintaining the temperature at 0°C. Then, the mixture was stirred at room temperature for 3 hours or longer to react. Dichloromethane and water were added to the reaction solution to separate the layers. After the organic layer was washed with water and dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was washed with hexane. Then, by recrystallizing with dichloromethane and hexane, 2.5 g of the compound represented by the following formula (6) was obtained as a pale yellow solid. The yield of the compound represented by formula (6) was 47%.

¹ H-NMR and ³¹ P-NMR measurements were performed on the obtained compound represented by formula (6), and the structure was identified according to the following results.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 7.85 (d, J = 7.8 Hz, 1 H), 7.67 (d, J = 6.4 Hz, 1 H), 7.53 (d, J = 7 .8Hz, 1H), 7.45 (t, J = 7.7Hz, 1H), 7.23 (m, 21H), 7.01 (t, J = 7.7Hz, 1H), 6.80 (dd , J=8.5, 3.6 Hz, 1 H), 6.66 (ddd, J=7.5, 3.6, 1.4 Hz, 1 H).
³¹ P-NMR (162 MHz, CDCl ₃ ): δ -17.4 (d, J = 21.9 Hz, 1 P), -20.5 (d, J = 21.9 Hz, 1 P)

Example except that 0.1369 g (4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst) of the bidentate phosphine ligand represented by formula (6) was used as the bidentate phosphine ligand An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in 2.

(Example 4)
<Production of bidentate phosphine ligand>
Phosphorus trichloride (4.3 mL, 50 mmol) and 300 mL of dehydrated diethyl ether were charged into a 500 mL three-necked flask that was purged with nitrogen, and diethylamine (10.4 mL, 100 mmol) was added thereto at -78°C over 30 minutes. Dripped. After completion of the dropwise addition, the mixture was stirred at room temperature for 16 hours to react, and the reaction solution was filtered. After the obtained filtrate was distilled to remove the solvent, the residue was distilled under reduced pressure to obtain 6.5 g of dichlorodiethylaminophosphine as a colorless liquid. The yield of dichlorodiethylaminophosphine was 75%.

5-bromo-m-xylene (25 g, 135.09 mmol) and 250 mL of dehydrated diethyl ether were charged in a three-necked flask with a capacity of 500 mL that was purged with nitrogen, and n-butyllithium solution (2. 5M hexane solution, 88.4 mL, 141.5 mmol) was added dropwise over 20 minutes. After completion of the dropwise addition, the mixture was stirred at a temperature of 0°C for 4 hours. Furthermore, dichlorodiethylaminophosphine (11.19 g, 64.33 mmol) was added and stirred at a temperature of 0° C. for 4 hours to synthesize [bis-(3,5-dimethylphenyl)](diethylamino)phosphine. After that, 33 mL of hydrogen chloride solution was added to the reaction solution in which [bis-(3,5-dimethylphenyl)](diethylamino)phosphine was synthesized while maintaining the temperature at 0° C., and the mixture was stirred at room temperature for 1 hour to react. The reaction solution was filtered through celite, the resulting filtrate was dried under reduced pressure to remove the solvent, and the residue was dried under reduced pressure over 1 day. A chlorophosphine was obtained. The obtained bis(3,5-dimethylphenyl)chlorophosphine was used for the next reaction without purification.

In a nitrogen-substituted three-necked flask with a capacity of 200 mL, the compound represented by the formula (5) (2 g, 9.13 mmol) and N,N,N',N'-tetramethylethylenediamine (4.11 ml, 27.49 mmol) ) and 100 mL of dehydrated diethyl ether were charged, and an n-butyllithium solution (2.5 M hexane solution, 11 mL, 27.49 mmol) was added dropwise over 20 minutes while maintaining the temperature at 0°C. After completion of dropping, the mixture was stirred at room temperature for 16 hours. Furthermore, bis(3,5-dimethylphenyl)chlorophosphine (excess amount) represented by the formula (7) was added while maintaining the temperature at 0°C. Then, the mixture was stirred at room temperature for 3 hours or longer to react. Dichloromethane and water were added to the reaction solution to separate the layers. After the organic layer was washed with water and dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was washed with hexane. After that, by recrystallizing with dichloromethane and hexane, 1.9 g of the compound represented by the following formula (8) was obtained as a pale yellow solid. The yield of the compound represented by formula (8) was 30%.

¹ H-NMR and ³¹ P-NMR measurements were performed on the obtained compound represented by formula (8), and the structure was identified by the following results.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 7.81 (d, J = 7.4 Hz, 1 H), 7.64 (d, J = 6.9 Hz, 1 H), 7.51 (d, J = 7 .4Hz, 1H), 7.47 (t, J = 7.4Hz, 1H), 7.17 (d, J = 8.2Hz, 1H), 7.00 (t, J = 7.4Hz, 1H) , 6.86-6.82.(m, 9H), 6.80(d, J=7.4Hz, 4H), 6.66(ddd, J=7.3, 3.4, 1.4Hz, 1H), 2.18 (d, J=4.6Hz, 24H).
³¹ P-NMR (162 MHz, CDCl ₃ ): δ -17.5 (d, J = 21.9 Hz, 1 P), -21.2 (d, J = 21.9 Hz, 1 P)

Example except that 0.1631 g (4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst) of the bidentate phosphine ligand represented by formula (8) was used as the bidentate phosphine ligand An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in 2.

(Example 5)
<Production of bidentate phosphine ligand>
Phenoxazine (5 g, 1.81 mmol) and 80 mL of dehydrated tetrahydrofuran were placed in a 200 mL two-necked flask purged with nitrogen, 1.65 g of sodium hydride was added, and the mixture was refluxed at 40° C. for 1 hour. . Thereafter, the temperature of the solution was lowered to room temperature, a mixed solution of 6.17 g of tert-butyldimethylchlorosilane and 10 mL of tetrahydrofuran was added, and the mixture was refluxed at a temperature of 70° C. for 3 hours or more to react. Then, the temperature of the reaction solution was lowered to room temperature, and the reaction solution was put into ice water to stop the reaction. Thereafter, ethyl acetate was added to the reaction solution, the organic layer was washed with water, dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by chromatography. As a result, 2.5 g of a compound represented by the following formula (9) was obtained as a white solid. The yield of the compound represented by formula (9) was 60%.

In a nitrogen-substituted three-necked flask with a capacity of 200 mL, the compound represented by the formula (9) (2 g, 6.73 mmol) and N,N,N',N'-tetramethylethylenediamine (1.64 ml, 14.12 mmol) ) and 100 mL of dehydrated diethyl ether were charged, and an n-butyllithium solution (2.5 M hexane solution, 8.82 mL, 14.12 mmol) was added dropwise over 10 minutes while maintaining the temperature at 0°C. After completion of dropping, the mixture was stirred at room temperature for 16 hours. Furthermore, bis(3,5-dimethylphenyl)chlorophosphine (excess amount) represented by the formula (7) was added while maintaining the temperature at 0°C. After that, the mixture was stirred at room temperature for 16 hours to react. Dichloromethane and water were added to the reaction solution to separate the layers. After the organic layer was washed with water and dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure to obtain a solid reaction product.

Subsequently, the obtained solid reaction product was dried, 50 mL of tetrahydrofuran was added, followed by tetrabutylammonium fluoride trihydrate (3.4 g, 10.76 mmol), and stirred at room temperature for 48 hours. , reacted. After that, the solvent was distilled off under reduced pressure, and dichloromethane and water were added to separate the layers. The organic layer was washed with water and dried over anhydrous sodium sulfate, and the residue was washed with hexane and ethanol. After that, by recrystallizing with dichloromethane and ethanol, 2.3 g of the compound represented by the following formula (10) was obtained as a pale gray solid. The yield of the compound represented by formula (10) was 50%.

¹ H-NMR and ³¹ P-NMR measurements were performed on the obtained compound represented by formula (10), and the structure was identified by the following results.
¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 7.18 (m, 8H), 6.66 (s, 4H), 6.46 (m, 4H), 5.74 (dd, J=6. 9, 2.8Hz, 2H), 4.01 (s, 2H), 1.96 (s, 24H)
³¹ P-NMR (162 MHz, CDCl ₃ ): δ -18.0

Example except that 0.1549 g (4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst) of the bidentate phosphine ligand represented by formula (10) was used as the bidentate phosphine ligand An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in 1.

(Comparative example 1)
Instead of the bidentate phosphine ligand, triphenylphosphine (PPh ₃ ) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), which is a monodentate phosphine ligand, is 0.0612 g (per mol of rhodium atoms contained in the rhodium catalyst). An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in Example 1, except that 4 mol) was used.

(Comparative example 2)
As a bidentate phosphine ligand, trans-4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl-1,3-dioxolane (DIOP) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.116 g ( An aqueous solution containing a reaction product containing 4-HBA was obtained in the same manner as in Example 2, except that 4 mol per 1 mol of rhodium atoms contained in the rhodium catalyst was used.

Conditions for the hydroformylation reaction of allyl alcohol in the methods for producing 4-HBA of Examples 1 to 5, Comparative Examples 1 and 2 (partial pressure (gauge pressure) of carbon monoxide gas in reaction vessel, hydrogen gas Partial pressure (gauge pressure)), reaction temperature, reaction time) are shown in Table 1, respectively.

In the methods for producing 4-HBA of Examples 1 to 5 and Comparative Example 2, the difference in activation energy between 1,2-insertion and 2,1-insertion in the hydroformylation reaction of allyl alcohol is shown below. Calculated by Table 1 shows the results.

[Method for calculating the difference in activation energy between 1,2 insertion and 2,1 insertion]
Using Gaussian 16, which is a software for quantum chemical calculation, the transition state calculation of the 1,2-insertion process and the 2,1-insertion process is performed based on the density functional theory (DFT method) wB97XD/6-31+G* method, The Gibbs free energy in each transition state was obtained from the vibrational analysis in that state.

Then, the difference between (1) the Gibbs free energy (activation energy) of the transition state of 1,2 insertion and (2) the Gibbs free energy (activation energy) of the transition state of 2,1 insertion ((2)- (1)) was calculated as the activation energy difference.

The calculation time for the activation energy of 1,2 insertion and the activation energy of 2,1 insertion varies depending on the type and molecular size of the bidentate phosphine ligand. Therefore, depending on the type and molecular size of the bidentate phosphine ligand, the computational cost may become enormous. For this reason, in the present invention, the Gibbs free energy of the transition state was calculated using the calculation technique described below while balancing the trade-off between calculation time and calculation accuracy.

That is, for bidentate phosphine ligands with a relatively small molecular weight of 700 or less, the above transition state under toluene solvent conditions in a continuous dielectric model (hereinafter sometimes referred to as "PCM model") Calculations were performed to obtain the Gibbs free energy. For bidentate phosphine ligands with a relatively large molecular weight of more than 700, the above transition state calculation or structure optimization was performed under gas phase conditions. After that, the optimized structure was subjected to vibrational analysis under toluene solvent conditions in the PCM model to calculate the Gibbs free energy (activation energy).

Regarding the bidentate phosphine ligand in Calculation Example 1 described later, although the molecular weight exceeds 700, the calculation time of the Gibbs free energy did not become enormous, so the above-mentioned used when the molecular weight is 700 or less We applied the method to obtain the Gibbs free energy.

In addition, depending on the type of aryl group in the aryl group that may have a substituent on the bidentate phosphine ligand, the bonding position of the substituent on the aryl group, etc., the convergence of the numerical calculation may not be good. Specifically, a situation occurs in which the four thresholds set as the convergence conditions in Gaussian 16 cannot be simultaneously satisfied within a practical time. In that case, the int (grid=ultrafine) option was used to improve the precision of integration to obtain the molecular structure necessary for calculating the activation energy.

In addition, with regard to 4-HBA, HMPA, and other by-products (propionaldehyde, 1-propyl alcohol (PrOH), GBL) obtained by the 4-HBA production methods of Examples 1 to 5 and Comparative Examples 1 and 2, Analyzed using liquid chromatography under the above analysis conditions, the conversion rate of allyl alcohol (AAL), the yield of 4-HBA, the yield of HMPA, the yield of other by-products, the amount of 4-HBA produced, and The ratio (4-HBA/HMPA) to the amount of HMPA produced was determined. Table 1 shows the results.

The yield of 4-HBA shown in Table 1 is the sum of the yield of 4-HBA and the yield of 2-hydroxytetrahydrofuran. Since 4-HBA in the aqueous solution is in equilibrium with 2-hydroxytetrahydrofuran, the yield of 2-hydroxytetrahydrofuran contained in the aqueous solution containing the reaction product was also converted into the yield of 4-HBA.

As shown in Table 1, reactions obtained in the methods for producing 4-HBA of Examples 1 to 5 using at least one selected from formulas (1) to (3) as bidentate phosphine ligands All of the products had a smaller amount of HMPA and a 4-HBA/HMPA ratio of 10.0 or more compared to the reaction products obtained by the 4-HBA production methods of Comparative Examples 1 and 2. , was big.
In particular, as a bidentate phosphine ligand, an optionally substituted aryl group is a compound represented by formula (8) or a compound represented by formula (10) represented by formula (b) In Examples 4 and 5 using the compound, the yield of 4-HBA was 90% or more, confirming that 4-HBA can be produced in high yield.

Further, as shown in Table 1, in the 4-HBA production methods of Examples 1 to 5, the 1,2-insertion activation energy and the 2,1-insertion activation energy calculated by the density functional theory difference was 4.2 kcal/mol or more. On the other hand, in the method for producing 4-HBA of Comparative Example 2, the difference in activation energy was less than 4.2 kcal/mol in spite of using a bidentate phosphine ligand. Therefore, the magnitude relationship of the calculated value of the activation energy difference in the 4-HBA production methods of Examples 1 to 5 and Comparative Example 2 is the same as that in the 4-HBA production methods of Examples 1 to 5 and Comparative Example 2. This coincided with the magnitude relationship of the experimental results for 4-HBA/HMPA. From this, it can be confirmed that 4-HBA/HMPA tends to increase as the difference in activation energy between 1,2 insertion and 2,1 insertion calculated by the density functional theory increases. The validity of the calculation method was confirmed.

(Calculation example 1 to calculation example 3)
When the compounds shown in Table 2 are used as bidentate phosphine ligands, the difference in activation energy between 1,2-insertion and 2,1-insertion in the hydroformylation reaction of allyl alcohol is calculated using the above calculation method. calculated by Table 2 shows the results.

As shown in Table 2, in the case of Calculation Examples 1 to 3 using the bidentate phosphine ligand shown in Table 2, the same density generalization as in the method for producing 4-HBA in Examples 1 to 5 The difference between the 1,2-insertion activation energy and the 2,1-insertion activation energy calculated by the function method was 4.2 kcal/mol or more. From this, even when the bidentate phosphine ligands shown in Table 2 were used instead of the bidentate phosphine ligands used in the methods for producing 4-HBA in Examples 1 to 5, 4-HBA/ Reaction products with high HMPA are expected to be obtained.

[Method for producing gamma-butyrolactone (GBL)]
As a fixed-bed gas-phase reactor, it has a cylindrical reaction vessel with a diameter of 4.5 mm and a height of 50 mm. and a reaction liquid collecting container (cooling) having a gas vent at the bottom of the reaction container was used.
CuZnZrAlCrOx (molar ratio Cu:Zn:Zr:Al:Cr=1.0:0.1:0.1:0.45:0.1) was produced as a copper-containing catalyst by a coprecipitation method.

0.8 g of the above copper-containing catalyst is packed in a reaction vessel of a fixed bed gas phase reactor, and hydrogen gas at 300 ° C. is passed through the reaction vessel at a flow rate of 30 mL / min for 1 hour to obtain a copper-containing catalyst. hydrogen reduction was performed.
After that, the 20% by mass aqueous solution of the reaction product containing 4-HBA produced in Example 1 was sent to the vaporizer at 0.1 ml/min to be vaporized, and nitrogen gas as a carrier gas was supplied from the top of the reaction vessel. It was fed at 10 ml/min and was brought into contact with a copper-containing catalyst at 300° C. for reaction to produce GBL. At this time, GHSV (gas hourly space velocity) was 8707 hr ^-1 and LHSV (liquid hourly space velocity in terms of raw material) was 1.5 hr ^-1 . The reaction product containing 4-HBA prepared in Example 1 was used as it was without purification.

As a result of analyzing the obtained GBL by HPLC, the conversion of 4-HBA was 98.5%, the GBL yield was 97.5%, and the GBL selectivity was 99.0%.
From this, the reaction product containing 4-HBA produced in Example 1 can produce GBL at a high yield even if it is used as it is for the reaction for producing GBL without purification, and GBL can be produced efficiently. I have confirmed that it is possible. This is because the 4-HBA/HMPA of the reaction product containing 4-HBA produced in Example 1 is large.

[Method for producing N-methyl-2-pyrrolidone (NMP)]
12.92 g of GBL produced by the above production method using the reaction product containing 4-HBA produced in Example 1 and 40% monomethylamine aqueous solution (Fujifilm 12.89 g (manufactured by Wako Pure Chemical Industries, Ltd.) (molar ratio of monomethylamine to 1 mol of GBL: 1.1) and 51.66 g of water as a solvent were added. Then, under a nitrogen gas atmosphere, the reaction initiation pressure was set to 101.3 kPa, and the reaction was allowed to proceed while stirring at 240° C. for 3 hours to generate NMP.

The resulting reaction solution containing NMP was analyzed using HPLC to determine the conversion rate of GBL and the yield of NMP. As a result, the conversion rate of GBL was 98.4% and the yield of NMP was 97.9%.
From this, it was confirmed that NMP can be efficiently produced at a high yield using GBL produced using the reaction product containing 4-HBA produced in Example 1 as a starting material.

The present invention provides a method for producing 4-HBA that produces a small amount of HMPA and yields a large 4-HBA/HMPA reaction product.

Claims (15)

1. A step of hydroformylating allyl alcohol with carbon monoxide gas and hydrogen gas in the presence of a rhodium catalyst and a catalyst containing at least one bidentate phosphine ligand selected from the following formulas (1) to (3): A method for producing 4-hydroxybutyraldehyde, comprising:
   

   

   
   (In formulas (1) to (3), Ar represents an aryl group which may have a substituent.)
2. The method for producing 4-hydroxybutyraldehyde according to claim 1, wherein Ar in the formulas (1) to (3) is represented by any one of the following formulas (a) to (e).
   

   
3. The hydroformylation reaction in the presence of a rhodium catalyst and said catalyst containing said bidentate phosphine ligand is calculated by the density functional theory, the activation energy of 1,2 insertion into allyl alcohol and 2,1 insertion The method for producing 4-hydroxybutyraldehyde according to claim 1 or 2, wherein the difference from the activation energy of is 4.2 kcal/mol or more.
4. Claim 1, wherein the bidentate phosphine ligand is represented by the formula (1), and Ar in the formula (1) is represented by any one of the formulas (a), (b), and (c). The method for producing 4-hydroxybutyraldehyde according to any one of claims 3 to 4.
5. The bidentate phosphine ligand is represented by the formula (2), and Ar in the formula (2) is represented by the formula (a), according to any one of claims 1 to 3. A method for producing 4-hydroxybutyraldehyde.
6. The bidentate phosphine ligand is represented by the formula (3), and Ar in the formula (3) is represented by any one of the formulas (a), (b), (d), and (e). , The method for producing 4-hydroxybutyraldehyde according to any one of claims 1 to 3.
7. The 4-hydroxy according to any one of claims 1 to 6, wherein the amount of the rhodium catalyst used is such that the ratio of rhodium atoms to the allyl alcohol is 0.01 mol% to 5 mol%. A method for producing butyraldehyde.
8. The amount of the bidentate phosphine ligand used is in the range of 0.5 mol to 50 mol per 1 mol of rhodium atoms contained in the rhodium catalyst, according to any one of claims 1 to 7. A process for the preparation of 4-hydroxybutyraldehyde described.
9. The pressure of the mixed gas containing carbon monoxide gas and hydrogen gas in the reaction vessel for the hydroformylation reaction is in the range of 0.1 to 10 MPaG (gauge pressure),
   Any one of claims 1 to 8, wherein the partial pressure ratio of carbon monoxide gas and hydrogen gas (hydrogen gas/carbon monoxide gas) in the reaction vessel is in the range of 1/10 to 10/1. The method for producing 4-hydroxybutyraldehyde according to .
10. The production of 4-hydroxybutyraldehyde according to any one of claims 1 to 9, wherein the carbon monoxide gas and the hydrogen gas are generated by thermal decomposition of waste plastics and/or biomass. Method.
11. A step of producing 4-hydroxybutyraldehyde by the method for producing 4-hydroxybutyraldehyde according to any one of claims 1 to 10;
    A method for producing gamma-butyrolactone, comprising the step of contacting the produced 4-hydroxybutyraldehyde with a copper-containing catalyst.
12. The method for producing gamma-butyrolactone according to claim 11, wherein the catalyst containing copper further contains an oxide of at least one metal element selected from the group consisting of zinc, zirconium and aluminum.
13. a step of producing gamma-butyrolactone by the method for producing gamma-butyrolactone according to claim 11 or 12;
    A method for producing N-methyl-2-pyrrolidone, comprising a step of reacting the produced gamma-butyrolactone with monomethylamine.
14. A compound represented by the following formula (10).
    

    
15. A compound represented by the following formula (8).