Method for producing dimethanol compounds having a norbornane skeleton

Abstract

A method for producing a desired compound represented by formula (1), the method comprising a step (A) for subjecting a mixed solution containing a starting compound represented by formula (2) and a solvent to hydrogenation reduction in the presence of a catalyst having a hydrogenating ability, in which the solvent is a linear or branched secondary or tertiary alcohol. (In formula (1), R represents H, CH3, or C2H5.) (In formula (2), R represents H, CH3, or C2H5; and R1 represents CH3, C2H5, C3H7, or C4H9.)

Description

[Technical Field]

[0001] The present invention relates to a method for producing a dimethanol compound having a norbornane skeleton. [Background technology]

[0002] Dimethanol compounds having a norbornane skeleton are known to exhibit excellent characteristics when used as adhesives or resin raw materials. For example, Patent Document 1 describes a method for producing a dimethanol compound having a norbornane skeleton by hydrogenating a corresponding ester compound. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 147242 Summary of the Invention [Problem to be solved by the invention]

[0004] Hydrogenation reactions are typically carried out by reacting an ester-containing compound with hydrogen gas using a catalyst containing copper oxide and a reaction solvent. In Patent Document 1, the substrate ester compound, toluene solvent, and copper oxide catalyst are charged, and the reaction is carried out at a reaction temperature of 215°C, a reaction pressure of 10 MPa, and a reaction time of 8 hours. However, the catalyst amount is 20 wt% relative to the substrate, and the toluene solvent amount is 300 wt% relative to the substrate. Furthermore, the resulting dimethanol compound has low solubility in toluene, resulting in a paste-like product of the catalyst, dimethanol compound, and unreacted ester compound, which precipitates in the toluene solvent. In this case, the catalyst can be separated by filtration by diluting with methanol after the reaction is complete, but it has been found that approximately 1% of the intermediate ester compound remains in the reaction solution in addition to the target dimethanol compound. When the target compound is used as a polymer raw material, intermediates that may accompany the target compound tend to inhibit the reaction. Furthermore, because both the target compound and the intermediate have high viscosity and high boiling points, it is difficult to separate them by simple distillation or thin-film distillation. It is also conceivable to use distillation purification with a large number of stages to separate the intermediate from the target compound, but this is not an economical method because it reduces the yield. Therefore, the technology of Patent Document 1 has room for improvement in terms of suppressing the production of intermediates.

[0005] On the other hand, by using an alcohol-based solvent, the problem of precipitation of a paste-like product in the solvent can be solved. However, in the case of methanol or ethanol, the high reaction temperature during the hydrogenation reaction causes a partial pressure, which reduces the hydrogen gas concentration in the gas phase, and the reaction time tends to be long, and therefore it is difficult to say that this method is economical. Furthermore, in Patent Document 1, cyclohexanol is used as a solvent, and although the low hydrogen gas concentration described above can be avoided, it has been found that a transesterification reaction occurs with some of the intermediates, and a by-product, a transesterification reaction product, is likely to be produced in the reaction solution. In this case, as with the intermediates described above, the reaction to polymerize tends to be inhibited, and since both the target compound and the by-product have high viscosity and high boiling points, it is difficult to separate the by-product from the target compound by simple distillation or thin-film distillation. Furthermore, using a high number of distillation stages for the separation reduces the yield, making it difficult to say that it is an economical method. Therefore, the technology of Patent Document 1 has room for improvement in terms of suppressing the generation of by-products.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for producing a dimethanol compound, which can suppress the production of both intermediates and by-products in the production of a dimethanol compound by a hydrogenation reaction.

[0007] The present inventors have found that the above-mentioned problems can be solved by using a specific alcohol as a solvent in a hydrogenation reaction in the production of a dimethanol compound having a norbornane skeleton, and have completed the present invention.

[0008] That is, the present invention is as follows. [1] A method for producing a target compound represented by the following formula (1): The method includes a step (A) of subjecting a mixed liquid containing a raw material compound represented by the following formula (2) and a solvent to hydrogenation reduction in the presence of a catalyst having hydrogenation ability, The production method, wherein the solvent is a linear or branched secondary alcohol or a tertiary alcohol. [ka] (In the formula (1), R represents H, CH, or C H ). [ka] (In the formula (2), R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9.) [2] The method according to [1], wherein the boiling point of the solvent is 100 to 230°C. [3] The method according to [1] or [2], wherein the solvent is represented by the following formula (a): [ka] (In the formula (a), R1 represents H or CH3. R2 represents CH 3、 C2H 5、 R3 represents C3H7 or C4H9. R3 represents C3H7, C4H9, C5H 11、 C6H 13、 C7H 15、 C8H 17、 C9H 19、 C 10 H 21、 C 11 H 23、 or C 12 H 25 represents.) [4] The production method according to any one of [1] to [3], wherein the content of the intermediate represented by the following formula (3) in the target compound is 0.5 mass % or less: [ka] (In the formula, R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9.) [5] The production method according to any one of [1] to [4], wherein the content of a by-product represented by the following formula (4) in the target compound is 0.5 mass % or less: [ka] (Wherein, R represents H, CH3, or C2H5. R2 represents C4H9, C5H 11 , C6H 13 , C7H 15 , C8H17 , C9H 19 , C 10 H 21 , C 11 H 23 , C 12 H 25 , C 13 H 27 , C 14 H 29 represents.) [6] The method according to any one of [1] to [5], wherein the solvent is 2-octanol and / or tetrahydrolinanol. [7] The production method according to any one of [1] to [6], wherein in the step (A), the catalyst is activated at a first temperature and a first pressure, and after the activation, the raw material compound is hydrogenated at a second temperature and a second pressure. [8] The manufacturing method according to [7], wherein the second pressure is greater than 5 MPa and less than 20 MPa. [9] The manufacturing method according to [7] or [8], wherein the second pressure is greater than 5 MPa and equal to or less than 8 MPa.

[10] The method according to [9], wherein the solvent is a linear or branched tertiary alcohol.

[11] The method according to

[10] , wherein the solvent is tetrahydrolinanol. [Effects of the Invention]

[0009] According to the production method of the present invention, it is possible to provide a production method that can suppress the production of both intermediates and by-products in the production of a dimethanol compound by a hydrogenation reaction. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out with appropriate modifications within the scope of its gist.

[0011] <Method of producing a dimethanol compound having a norbornane skeleton> The production method of this embodiment is a method for producing a target compound represented by the following formula (1) (i.e., a dimethanol compound having a norbornane skeleton represented by the above formula (1); hereinafter, also simply referred to as "target compound"), and includes a step (A) of subjecting a mixed liquid containing a raw material compound represented by the following formula (2) and a solvent to hydrogenation reduction in the presence of a catalyst having hydrogenation ability, wherein the solvent is a linear or branched secondary alcohol or tertiary alcohol. [ka] (In the formula (1), R represents H, CH, or C H ). [ka] (In the formula (2), R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9.)

[0012] Since the production method of this embodiment is configured as described above, it is possible to suppress the production of both intermediates and by-products in the production of a dimethanol compound by a hydrogenation reaction. Such a target compound can be preferably used as a paint additive, adhesive, resin raw material, etc.

[0013] The synthetic route for producing the target compound is not limited to the following, but for example, a synthetic route shown in the following formula (I) can be adopted using dicyclopentadiene or cyclopentadiene and an olefin having a functional group as raw materials. [ka] (In the above formula (I), R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9. R2 represents an organic group in a linear or branched secondary or tertiary alcohol, preferably C4H9, C5H 11 , C6H 13 , C7H 15 , C8H 17 , C9H 19 , or C 10 H 21 represents.)

[0014] Formula (3) in the above formula (I) represents a synthetic intermediate that can accompany the target compound. Hereinafter, for the sake of convenience, this synthetic intermediate will also be referred to simply as "intermediate." Furthermore, formula (4) in the above formula (I) represents a by-product that can accompany the target compound, and hereinafter, for the sake of convenience, this will also be referred to simply as "by-product."

[0015] [Monoolefin having 14 to 19 carbon atoms represented by formula (5)] In this embodiment, the monoolefin having 14 to 19 carbon atoms and represented by the following formula (5) can be produced by carrying out a Diels-Alder reaction between an olefin having a functional group and dicyclopentadiene. [ka] (In formula (5), R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9.)

[0016] Examples of the olefin having a functional group used in the Diels-Alder reaction include, but are not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and among these, methyl methacrylate, ethyl methacrylate, methyl acrylate, and ethyl acrylate are preferred.

[0017] The dicyclopentadiene used in the Diels-Alder reaction of this embodiment is preferably high-purity, and the content of impurities such as butadiene and isoprene is preferably low. The purity of dicyclopentadiene is preferably 90% or higher, more preferably 95% or higher. It is also known that dicyclopentadiene depolymerizes to cyclopentadiene (so-called monocyclopentadiene) under heating conditions, so cyclopentadiene can be used instead of dicyclopentadiene. It is believed that the monoolefin having 14 to 19 carbon atoms represented by the above formula (5) is essentially produced via a monoolefin having 9 to 14 carbon atoms represented by the following formula (6) (first-stage Diels-Alder reaction product). The produced monoolefin represented by the following formula (6) is then subjected to a Diels-Alder reaction (second-stage Diels-Alder reaction) with cyclopentadiene (diene) present in the reaction system as a new dienophile, thereby producing the monoolefin having 14 to 19 carbon atoms represented by the above formula (5). [ka] (In formula (6), R represents H, CH3, or C2H5. R1 represents CH3, C2H5, C3H7, or C4H9.)

[0018] The presence of cyclopentadiene in the reaction system tends to promote efficient progress of the two-stage Diels-Alder reaction, so the reaction temperature for the Diels-Alder reaction is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher. On the other hand, in order to suppress the by-production of high-boiling substances, the reaction is preferably carried out at a temperature of 250°C or lower. Furthermore, hydrocarbons, alcohols, esters, and the like can also be used as reaction solvents, and preferred examples include aliphatic hydrocarbons having 6 or more carbon atoms, cyclohexane, toluene, xylene, ethylbenzene, mesitylene, propanol, and butanol.

[0019] The Diels-Alder reaction can be carried out in a variety of reaction systems, including a batch system using a tank reactor or the like, a semi-batch system in which a substrate or a substrate solution is supplied to a tank reactor under reaction conditions, and a continuous flow system in which substrates are passed through a tubular reactor under reaction conditions.

[0020] The reaction product obtained by the Diels-Alder reaction (monoolefin having 14 to 19 carbon atoms and represented by the above formula (5)) can be used as it is as a raw material for the subsequent hydroformylation reaction, or it may be purified by a method such as distillation, extraction, or crystallization and then subjected to the subsequent step. Note that the monoolefin having 14 to 19 carbon atoms and represented by the above formula (5) is not limited to those synthesized as described above, and any commercially available product may be used in the production method of this embodiment.

[0021] [Starting compound represented by formula (2)] The raw material compound represented by formula (2) in formula (I) above can be produced, for example, by hydroformylating a monoolefin having 14 to 19 carbon atoms represented by formula (5) with carbon monoxide and hydrogen gas in the presence of a rhodium compound and an organophosphorus compound.

[0022] The rhodium compound used in the hydroformylation reaction is not particularly limited, and examples thereof include compounds that form complexes with organophosphorus compounds and exhibit hydroformylation activity in the presence of carbon monoxide and hydrogen, such as rhodium acetylacetonate dicarbonyl (hereinafter also referred to as "Rh(acac)(CO)"), RhO, and Rh(CO). 12 , Rh6(CO) 16Alternatively, a catalyst precursor such as Rh(NO3)3 may be introduced into the reaction mixture together with the organophosphorus compound to form a catalytically active rhodium-metal hydride carbonyl phosphorus complex in the reaction vessel, or a rhodium-metal hydride carbonyl phosphorus complex may be prepared in advance and introduced into the reactor. In this embodiment, it is preferable to react Rh(acac)(CO)2 with the organophosphorus compound in the presence of a solvent, and then introduce the resulting catalytically active rhodium-organophosphorus complex into the reactor together with an excess of the organophosphorus compound, and use it in the hydroformylation reaction.

[0023] The amount of the rhodium compound used in the hydroformylation reaction is preferably 0.1 to 60 micromoles, more preferably 0.1 to 30 micromoles, even more preferably 0.2 to 20 micromoles, and even more preferably 0.5 to 10 micromoles, per mole of the monoolefin having 14 to 19 carbon atoms and represented by formula (5), which is the substrate of the hydroformylation reaction. By using an amount of the rhodium compound that is less than 60 micromoles per mole of the monoolefin having 14 to 19 carbon atoms, it is possible to reduce the cost of the rhodium catalyst without installing a recovery and recycling facility for the rhodium complex, thereby reducing the economic burden associated with the recovery and recycling facility.

[0024] In the above hydroformylation reaction, the organophosphorus compound that forms a catalyst for the hydroformylation reaction together with the rhodium compound includes a phosphine represented by the general formula P(-R1)(-R2)(-R3) or a phosphite represented by the general formula P(-OR1)(-OR2)(-OR3). Specific examples of R1, R2, and R3 in the above general formula include an aryl group that may be substituted with an alkyl or alkoxy group having 1 to 4 carbon atoms, and an alicyclic alkyl group that may be substituted with an alkyl or alkoxy group having 1 to 4 carbon atoms. Triphenylphosphine and triphenylphosphite are preferred. The amount of the organophosphorus compound used is preferably 300 to 10,000 times, more preferably 500 to 10,000 times, even more preferably 700 to 5,000 times, and even more preferably 900 to 2,000 times the molar amount of rhodium atoms in the rhodium compound. When the amount of the organophosphorus compound used is 300 times or more the moles of rhodium atoms, the rhodium metal hydride carbonyl phosphorus complex as the catalytic active material tends to contribute to stability, resulting in an improvement in reaction efficiency. On the other hand, when the amount of the organophosphorus compound used is 10,000 times or less the moles of rhodium atoms, economic efficiency tends to improve in terms of the cost of the organophosphorus compound.

[0025] The hydroformylation reaction can be carried out without using a solvent, but is preferably carried out using a solvent inert to the reaction. The solvent is not particularly limited as long as it dissolves the monoolefin having 14 to 19 carbon atoms represented by formula (5), dicyclopentadiene or cyclopentadiene, the rhodium compound, and the organophosphorus compound. Specific examples include hydrocarbons such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons; esters such as aliphatic esters, alicyclic esters, and aromatic esters; alcohols such as aliphatic alcohols and alicyclic alcohols; and aromatic halides. Among these, hydrocarbons are preferred, and among these hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons are preferred.

[0026] The temperature when carrying out the hydroformylation reaction is preferably 40°C to 160°C, more preferably 80°C to 140°C. When the reaction temperature is 40°C or higher, a sufficient reaction rate can be obtained and the amount of residual monoolefin starting material can be reduced. Furthermore, by keeping the reaction temperature at 160°C or lower, the generation of by-products derived from the monoolefin starting material and the reaction product can be reduced, and a decrease in reaction performance can be prevented.

[0027] The hydroformylation reaction is carried out under pressure with carbon monoxide (hereinafter also referred to as "CO") and hydrogen (hereinafter also referred to as "H2") gases. CO and H2 gases can be introduced into the reaction system independently, or they can be introduced into the reaction system as a pre-prepared mixed gas. The molar ratio of CO and H2 gases introduced into the reaction system (=CO / H2) is preferably 0.2 to 5, more preferably 0.5 to 2, and even more preferably 0.8 to 1.2. When the molar ratio of CO and H2 gases is within the above range, the reaction activity of the hydroformylation reaction and the selectivity for the target aldehyde tend to be improved. Note that the CO and H2 gases introduced into the reaction system decrease as the reaction progresses, so the use of a pre-prepared mixed gas of CO and H2 may simplify reaction control.

[0028] The reaction pressure of the hydroformylation reaction is preferably 1 to 12 MPa, more preferably 1.2 to 8 MPa, and even more preferably 1.5 to 5 MPa. A reaction pressure of 1 MPa or higher tends to facilitate a sufficient reaction rate and reduce the amount of residual monoolefins (the starting material). Furthermore, a reaction pressure of 12 MPa or lower tends to be economically advantageous because it eliminates the need for expensive equipment with excellent pressure resistance. In particular, when the reaction is carried out in a batch or semi-batch system, CO and H gas are discharged and the pressure is reduced after the reaction is complete, and therefore, the lower the pressure, the less CO and H gas are lost, which tends to be economically advantageous.

[0029] The hydroformylation reaction is preferably carried out as a batch or semi-batch reaction. The semi-batch reaction can be carried out by adding the rhodium compound, the organophosphorus compound, and the solvent to a reactor, pressurizing the reactor with CO / H gas, heating the reactor, and then adjusting the reaction conditions as described above, and then feeding the raw material monoolefin or a solution thereof to the reactor.

[0030] The reaction product obtained in the hydroformylation reaction can be used as it is as a raw material for the subsequent reduction reaction, but it may also be subjected to the subsequent step after purification, for example, by distillation, extraction, crystallization, etc. The raw material compound represented by the formula (2) is not limited to those synthesized as described above, and any commercially available product may be used in the production method of this embodiment.

[0031] [Process (A)] The production method of this embodiment includes step (A) of subjecting a mixed solution containing a raw material compound represented by formula (2) and a solvent to hydrogenation reduction in the presence of a catalyst having hydrogenation ability (hereinafter also referred to as a "hydrogenation catalyst"). In this embodiment, a linear or branched secondary alcohol or tertiary alcohol is used as the solvent in step (A). The use of such a solvent not only enables the production of a target compound from the raw material compound but also suppresses the production of both intermediates and by-products. The reason why the use of the solvent in this embodiment can suppress the production of both intermediates and by-products is not necessarily clear, but is predicted as follows. That is, with linear or branched secondary alcohols and / or tertiary alcohols, due to appropriate steric hindrance, transesterification, which causes by-products, is unlikely to occur, and even if it does occur, it is thought that the target product is likely to be obtained by subsequent hydrogenation. However, the mechanism of action of this embodiment is not limited to the above.

[0032] In step (A), the use of a linear or branched secondary alcohol and / or tertiary alcohol as a solvent is important for the reduction reaction in this embodiment. If aliphatic hydrocarbons, alicyclic hydrocarbons, or aromatic hydrocarbons are used in the hydrogenation reaction, the resulting dimethanol compound is poorly soluble in the solvent, resulting in a paste-like product of the catalyst, the dimethanol compound, and unreacted ester compound, which tends to precipitate in the solvent. While the use of an alcoholic solvent can solve the problem of the paste-like product, using a primary alcohol such as methanol or ethanol as the hydrogenation solvent creates a partial pressure due to the high reaction temperature during the hydrogenation reaction, resulting in a low hydrogen gas concentration in the gas phase, requiring a long reaction time. Furthermore, the inventors have found that, for example, using cyclohexanol, a cyclic alcohol, can solve the problems of the paste-like product and the low hydrogen gas concentration in the gas phase, but a partial transesterification reaction with the ester compound occurs, resulting in approximately 1% of the transesterification reaction product remaining in the hydrogenation reaction solution. In contrast to the above, by carrying out hydrogenation using a linear or branched secondary alcohol and / or tertiary alcohol as a solvent, the problems of a paste-like product, a low hydrogen gas concentration in the gas phase, and 1% or more of the transesterification reaction product remaining can be solved.

[0033] The linear or branched secondary alcohol and / or tertiary alcohol is not particularly limited, and examples thereof include secondary alcohols such as 2-octanol, 2-nonanol, 2-decanol, 4-decanol, 2-undecanol, 3-undecanol, 4-undecanol, 5-undecanol, 2-dodecanol, 2-tridecanol, and 2-tetradecanol; and tertiary alcohols such as tetrahydrolinanol, 3-methyl-3-heptanol, 3-ethyl-3-pentanol, 4-methyl-4-heptanol, 3,4-dimethyl-3-hexanol, 3,5-dimethyl-3-hexanol, and 3-ethyl-2-methyl-3-pentanol.

[0034] In this embodiment, from the viewpoint of more effectively suppressing the production of intermediates and by-products, the boiling point of the solvent is preferably 100 to 230° C., more preferably 140 to 220° C., and even more preferably 160 to 200° C. The boiling point is a known value as the boiling point of the target solvent at room temperature and normal pressure.

[0035] In this embodiment, from the viewpoint of more effectively suppressing the production of intermediates and by-products, the solvent is preferably represented by the following formula (a): [ka] (In the formula (a), R1 represents H or CH3. R2 represents CH 3、 C2H 5、 R3 represents C3H7 or C4H9. R3 represents C3H7, C4H9, C5H 11、 C6H 13、 C7H 15、 C8H 17、 C9H 19、 C 10 H 21、 C 11 H 23、 or C 12 H 25 represents.) Among the above, solvents such as 2-octanol and tetrahydrolinanol are particularly preferred.

[0036] The hydrogenation catalyst used in step (A) is, but is not limited to, a catalyst containing at least one element selected from the group consisting of copper, chromium, iron, zinc, and aluminum. Among these, copper-based catalysts such as Cu-Cr catalysts, Cu-Zn catalysts, Cu-Zn-Al catalysts, and Cu-Fe-Al catalysts are preferred, and Cu-Cr catalysts and Cu-Zn-Al catalysts are more preferred.

[0037] The amount of the hydrogenation catalyst used is not particularly limited, but is preferably 1 to 50% by mass relative to the substrate, i.e., the raw material compound represented by formula (2). When the amount of the hydrogenation catalyst used is 1% by mass or more, the reaction proceeds sufficiently, and as a result, the yield of the target product tends to be improved. Furthermore, even if the amount of the hydrogenation catalyst used exceeds 50% by mass, the effect of improving the reaction rate commensurate with the amount of catalyst used in the reaction tends not to be obtained, so from an economical point of view, it is preferable to keep the amount used at 50% by mass or less. In other words, by setting the amount of the hydrogenation catalyst used within the above-mentioned range, the hydrogenation reaction tends to be carried out efficiently. From the above viewpoint, the amount of the hydrogenation catalyst used is more preferably 2 to 20% by mass, and even more preferably 5 to 10% by mass.

[0038] In this embodiment, from the viewpoint of further increasing the reaction efficiency, it is preferable to activate the catalyst at a first temperature and a first pressure in step (A), and then, after the activation, hydrogenate the raw material compound at a second temperature and a second pressure. As described above, since by-produced water is thought to deactivate the activated hydrogenation catalyst, it is preferable to remove water before hydrogenation.

[0039] Activation of the hydrogenation catalyst is an operation for reducing the hydrogenation catalyst and can be carried out at a first temperature and a first pressure. In this embodiment, the first temperature is preferably 100°C or higher and 170°C or lower. When the first temperature is 170°C or lower, the occurrence of side reactions and decomposition reactions tends to be suppressed. Furthermore, when the first temperature is 100°C or higher, the reduction reaction of the catalyst tends to be completed within an appropriate time. From the same viewpoint, the first temperature is more preferably 120°C or higher and 170°C or lower. In this embodiment, the first pressure is preferably 0.5 MPa or more and 5 MPa or less. When the first pressure is 0.5 MPa or more, a sufficient reaction rate tends to be obtained, and when it is 5 MPa or less, the loss of H gas during water removal tends to be small, which tends to be economically advantageous. From the same viewpoint, the first pressure is more preferably 1 MPa or more and 3 MPa or less, and even more preferably 1.5 MPa or more and 2 MPa or less. In this embodiment, the reaction time for activating the hydrogenation catalyst is preferably 0.2 hours or more and 3 hours or less. When the first reaction time is 0.2 hours or more, the reduction state of the catalyst tends to be better, and when the first reaction time is 3 hours or less, the reaction time tends to be reduced while the reduction reaction of the catalyst proceeds sufficiently.

[0040] Although activation of the hydrogenation catalyst may be performed in the absence of the raw material compound, in this embodiment, activation is preferably performed in the presence of the raw material compound from the viewpoint of reaction efficiency. When activation of the hydrogenation catalyst is performed in the presence of the raw material compound, water is by-produced as reduced water. The procedure for removing such water is not particularly limited, but may include, for example, purging the gas phase several times to remove water present in the gas phase from the reaction system, or installing a nozzle line in the mixed solution in advance and bubbling inert gas such as H2 gas or N2 to remove water from the reaction system. To determine whether the treatment is complete, a trap may be installed at the end of the exhaust gas and the operation may be continued until the amount of water reaches 2 to 3 times the expected amount, or the moisture content of the reaction solution may be measured.

[0041] The hydrogenation of the starting compound is an operation to obtain the target compound and can be carried out at a second temperature and a second pressure. In this embodiment, the second temperature is preferably higher than 170°C and not higher than 250°C. When the second temperature is not higher than 250°C, the occurrence of side reactions and decomposition reactions tends to be suppressed, and the target compound tends to be obtained in a high yield. Furthermore, when the second temperature is higher than 170°C, the reaction tends to be completed within a reasonable time, and a decrease in productivity and a decrease in the yield of the target product tend to be avoided. From the same viewpoint, the second temperature is more preferably not lower than 190°C and not higher than 230°C. In this embodiment, the second pressure is preferably greater than 5 MPa and equal to or less than 20 MPa. When the second pressure is equal to or less than 20 MPa, the occurrence of side reactions and decomposition reactions tends to be suppressed, and the target compound tends to be obtained in a high yield. Furthermore, when the second pressure is greater than 5 MPa, the reaction tends to be completed within a reasonable time. From the same viewpoint, the second pressure is more preferably greater than 5 MPa and equal to or less than 15 MPa, and even more preferably greater than 5 MPa and equal to or less than 12 MPa. In terms of reactor design (equipment cost), it is preferable to carry out the hydrogenation at a low pressure. From this perspective, the second pressure is preferably 8 MPa or less, and more preferably more than 5 MPa but not more than 8 MPa. Under such conditions, the reaction time tends to be long. Here, if the reaction temperature is increased to shorten the reaction time, the amount of intermediates and by-products tends to increase. However, even in such cases, the use of the solvent of this embodiment can significantly reduce the production of intermediates and by-products. In this embodiment, from the perspective of more effectively reducing the production of intermediates and by-products when the second pressure is 8 MPa or less, it is preferable to use a linear or branched tertiary alcohol as the solvent in step (A), and it is particularly preferable to use tetrahydrolinanol as the solvent. From the above viewpoint, in this embodiment, when tetrahydrolinalool is used as a solvent, it is preferable that the second pressure is more than 5 MPa and not more than 8 MPa, and the second temperature is 215°C or more and 250°C or less; from the viewpoint of further reducing the reaction time, when tetrahydrolinalool is used as a solvent, it is more preferable that the second pressure is more than 5 MPa and not more than 8 MPa, and the second temperature is 220°C or more and 250°C or less. In the hydrogenation in this embodiment, a gas inert to the hydrogenation reaction (for example, nitrogen or argon) may be present. The pressures mentioned above refer to values ​​as hydrogen partial pressures.

[0042] In this embodiment, from the viewpoint of the physical properties obtained when the target compound is further processed, the content of the intermediate represented by the above formula (3) in the target compound obtained in step (A) in this embodiment is preferably 0.5 mass% or less. The content of the intermediate can be measured based on the method described in the Examples below. Furthermore, the content of the intermediate can be adjusted to the above range by using a linear or branched secondary alcohol and / or a tertiary alcohol in step (A), for example.

[0043] In this embodiment, from the viewpoint of the physical properties obtained when the target compound is further processed, it is preferable that the content of the by-product represented by the above formula (4) in the target compound obtained in step (A) in this embodiment is 0.5 mass% or less. The content of the intermediate can be measured based on the method described in the Examples below. Furthermore, the content of the intermediate can be adjusted to the above range by using a linear or branched secondary alcohol and / or a tertiary alcohol in step (A), for example.

[0044] The target compound obtained in step (A) of this embodiment can be purified, for example, by distillation, extraction, crystallization, or the like. [Example]

[0045] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0046] <Analysis method> (1) Gas chromatographic analysis conditions Analytical equipment: Shimadzu Corporation capillary gas chromatograph GC-2010 Plus Analytical column 1: GL Sciences, InertCap1 (30 m, 0.32 mm I.D., film thickness 0.25 μm) Oven temperature 1: 60°C (0.5 min) - 15°C / min - 280°C (4 min) Detector 1: FID, temperature 280℃ Internal standard: paraxylene Analytical column 2: GL Sciences, InertCapWAX (30 m, 0.32 mm I.D., film thickness 0.25 μm) Oven temperature 2: 60°C (0.5 min) - 20°C / min - 250°C (20 min) Detector 2: FID, temperature 250℃ (2)GC-MS measurement conditions Analytical equipment: Shimadzu Corporation, GCMS-QP2010 Plus Ionization voltage: 70V Analytical column: Agilent Technologies, DB-1 (30 m, 0.32 mm I.D., film thickness 1.00 μm) Oven temperature: 60°C (0.5 min) - 15°C / min - 280°C (4 min)

[0047] Example 1

[0048] (Obtaining monoolefins) A 500 mL stainless steel reactor was charged with 215 g (2.50 mol) of methyl acrylate and 165 g (1.25 mol) of dicyclopentadiene, and the reaction was carried out for 2 hours at 220° C. A reaction liquid containing 152 g of a monoolefin represented by the following formula (5a) was obtained, and after distillation and purification, a portion was subjected to the subsequent reaction. [ka]

[0049] (Obtaining aldehydes) The hydroformylation reaction of the monoolefin represented by formula (5a) was carried out in a 500 mL stainless steel reactor. The reactor was charged with 100 g of the distilled and purified monoolefin represented by formula (5a), 96 g of 2-octanol (Kokura Synthetic Industries), 213 mg of triphenyl phosphite (Wako Pure Chemical Industries, Ltd.) (1500 mol ppm relative to the monoolefin), and 355 μg of Rh(acac)(CO)2 (N.E. Chemcat Corporation) (3 mol ppm relative to the monoolefin). The atmosphere in the reactor was replaced with nitrogen and a CO / H2 mixed gas three times each, after which the system was pressurized with a CO / H2 mixed gas and the reaction was carried out at 100 °C and 2 MPa for 3 hours. After completion of the reaction, the reaction solution was analyzed by gas chromatography and GC-MS. As a result, it was found that the reaction solution contained 112.6 g of a raw material compound represented by the following formula (2a) having a molecular weight of 248 as the main product (substrate conversion rate 100% (= (charged monoolefin - remaining charged monoolefin) / charged monoolefin) × 100%), and the aldehyde yield was 99.5% (= main product / charged monoolefin × 100%). Next, the raw material compound represented by formula (2a) was purified by distillation, and a portion thereof was subjected to the subsequent reaction. [ka]

[0050] (Reduction of catalyst) A 300 mL stainless steel reactor equipped with a nitrogen bubbling nozzle was charged with 54.94 g of the distilled and purified raw material compound represented by formula (2a), 8.24 g of Cu-Zn-Al catalyst (E-01X, manufactured by JGC Catalysts and Chemicals Co., Ltd.), and 120.86 g of 2-octanol (manufactured by Kokura Synthetic Industries Co., Ltd.). The atmosphere in the reactor was replaced with nitrogen and H2 gas three times each, after which the system was pressurized with H2 gas and the catalyst was reduced at 150 °C and 2 MPa for 1 hour. A trap was installed in the exhaust gas line, and the pressure was reduced to 0 MPa while maintaining the temperature at 150 °C. A small amount of nitrogen gas was then introduced through the nitrogen bubbling nozzle to remove the reduced water from the reaction solution. The trapped volume was 3.90 g.

[0051] (Obtaining dimethanol by hydrogenation reaction) Subsequently, the atmosphere in the reactor was replaced with H2 gas three times, and then the system was pressurized with H2 gas and the hydrogenation reaction was carried out at 215°C and 9.5 MPa. 2-octanol was used as the solvent for the hydrogenation reaction. During the reaction, sampling was carried out every 5 hours. The sample solution was diluted with acetone, and the catalyst was filtered through a membrane filter with a pore size of 0.2 μm. Gas chromatography and GC-MS analyses were then used to quantitatively analyze the target compound represented by the following formula (1a) with a molecular weight of 222 as the main product, as well as the ester compound (intermediate) represented by the following formula (3a) with a molecular weight of 250 and the transesterification compound (by-product) represented by the following formula (4a) with a molecular weight of 349. The quantitative analysis was performed using analytical column 2 (InertCapWAX). After 15 hours, the amount of the intermediate represented by formula (3a) was 0.45% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4a) was 0.42% (= by-product represented by formula (4a) / (all components other than 2-octanol and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 47.46 g of the target compound represented by formula (1a) (substrate conversion rate 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%)), and the yield of the target compound was 96.50% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (the distillation plate count was one, the distillation temperature was 170-180 °C, and the vacuum was 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). It was confirmed that the main fraction containing the target compound represented by formula (1a) was 44.03 g, the dimethanol purity was 99.17% (= target compound represented by formula (1a) / (all components other than acetone) × 100)), and the distillation yield was 92.00% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX). The amount of the intermediate represented by formula (3a) was 0.43% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4a) was 0.40% (=by-product represented by formula (4a) / (all components other than 2-octanol and acetone)×100). [ka]

[0052] <Comparative Example 1> A hydrogenation reaction was carried out in the same manner as in Example 1, except that 1-octanol was used instead of 2-octanol as the solvent for the hydrogenation reaction. After 15 hours, the amount of the intermediate represented by formula (3a) was 0.47% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4b) was 4.23% (= by-product represented by formula (4b) / (all components other than 2-octanol and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 45.58 g of the target compound represented by formula (1a) (substrate conversion rate: 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%), and dimethanol yield: 92.67% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (the distillation plate count was one, the distillation temperature was 170-180 °C, and the vacuum was 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The results confirmed that the main fraction containing the target compound represented by formula (1a) was 40.49 g, the dimethanol purity was 98.28% (= target compound represented by formula (1a) / (all components other than acetone) × 100), and the distillation yield was 87.30% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX), and the amount of the intermediate represented by formula (3a) was 0.45% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4b) was 1.27% (=by-product represented by formula (4b) / (all components other than 2-octanol and acetone)×100). In this embodiment, since no solvent was used, the hydrogenation yield was low and the product contained a large amount of the by-product represented by formula (4b), resulting in low product purity. [ka]

[0053] <Comparative Example 2> A hydrogenation reaction was carried out in the same manner as in Example 1, except that 2-ethylhexanol was used instead of 2-octanol as the solvent for the hydrogenation reaction. After 15 hours, the amount of the intermediate represented by formula (3a) was 0.30% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4c) was 3.93% (= by-product represented by formula (4c) / (all components other than 2-octanol and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 45.81 g of the target compound represented by formula (1a) (substrate conversion rate: 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%), and dimethanol yield: 93.14% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (the distillation plate count was one, the distillation temperature was 170-180 °C, and the vacuum was 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The results confirmed that the main fraction containing the target compound represented by formula (1a) was 40.85 g, the dimethanol purity was 98.46% (= target compound represented by formula (1a) / (all components other than acetone) × 100), and the distillation yield was 87.80% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX), and the amount of the intermediate represented by formula (3a) was 0.29% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4c) was 1.26% (=by-product represented by formula (4c) / (all components other than 2-octanol and acetone)×100). In this embodiment, since no solvent was used, the hydrogenation yield was low, and the product contained a large amount of the by-product represented by formula (4c), resulting in low product purity. [ka]

[0054] <Example 2> A hydrogenation reaction was carried out in the same manner as in Example 1, except that tetrahydrolinanol was used instead of 2-octanol as the solvent for the hydrogenation reaction. After 15 hours, the amount of the intermediate represented by formula (3a) was 0.35% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4d) was 0% (= by-product represented by formula (4d) / (all components other than 2-octanol and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 48.11 g of the target compound represented by formula (1a) (substrate conversion rate: 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%), and dimethanol yield: 97.82% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (the distillation plate count was one, the distillation temperature was 170-180 °C, and the vacuum was 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The results confirmed that the main fraction containing the target compound represented by formula (1a) was 44.99 g, the dimethanol purity was 99.67% (= target compound represented by formula (1a) / (all components other than acetone) × 100), and the distillation yield was 93.20% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX), and the amount of the intermediate represented by formula (3a) was 0.33% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). In addition, the amount of the by-product represented by formula (4d) was 0.00% (=by-product represented by formula (4d) / (all components other than 2-octanol and acetone)×100). The use of the solvent in this embodiment resulted in a high hydrogenation yield and a low amount of the by-product represented by formula (4d), resulting in a high product purity. [ka]

[0055] <Comparative Example 3> A hydrogenation reaction was carried out in the same manner as in Example 1, except that cyclohexanol was used instead of 2-octanol as the solvent for the hydrogenation reaction. After 15 hours, the amount of the intermediate represented by formula (3a) was 0.50% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4e) was 0.96% (= by-product represented by formula (4e) / (all components other than 2-octanol and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 47.17 g of the target compound represented by formula (1a) (substrate conversion rate: 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%), and dimethanol yield: 95.91% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (the distillation plate count was one, the distillation temperature was 170-180 °C, and the vacuum was 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The results confirmed that the main fraction containing the target compound represented by formula (1a) was 43.76 g, the dimethanol purity was 98.64% (= target compound represented by formula (1a) / (all components other than acetone) × 100), and the distillation yield was 91.50% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX), and the amount of the intermediate represented by formula (3a) was 0.45% (= intermediate represented by formula (3a) / (all components other than 2-octanol and acetone) × 100). The amount of the by-product represented by formula (4e) was 0.91% (=by-product represented by formula (4e) / (all components other than 2-octanol and acetone)×100). In this embodiment, since the solvent was not used, the hydrogenation yield was low, and the product contained a large amount of the by-product represented by formula (4e), resulting in low product purity. [ka]

[0056] The reaction conditions and results of the reaction in Examples 1 and 2 and Comparative Examples 1 to 3 are shown in Table 1.

[0057] [Table 1]

[0058] Example 3 (Obtaining aldehydes) The hydroformylation reaction of the monoolefin represented by formula (5a) was carried out in a 500 mL stainless steel reactor. The reactor was charged with 100 g of the distilled and purified monoolefin represented by formula (5a), 96 g of 2-octanol (Kokura Synthetic Industries), 213 mg of triphenyl phosphite (Wako Pure Chemical Industries, Ltd.) (1500 mol ppm relative to the monoolefin), and 355 μg of Rh(acac)(CO)2 (N.E. Chemcat Corporation) (3 mol ppm relative to the monoolefin). The atmosphere in the reactor was replaced with nitrogen and a CO / H2 mixed gas three times each, after which the system was pressurized with a CO / H2 mixed gas and the reaction was carried out at 100 °C and 2 MPa for 3 hours. After completion of the reaction, the reaction solution was analyzed by gas chromatography and GC-MS. As a result, it was found that a reaction solution containing 112.6 g of the raw material compound represented by the above formula (2a) was obtained as the main product (substrate conversion rate 100% (= (charged monoolefin - remaining charged monoolefin) / charged monoolefin) × 100%), and the aldehyde yield was 99.5% (= main product / charged monoolefin × 100%)). Next, the raw material compound represented by formula (2a) was purified by distillation, and a portion thereof was subjected to the subsequent reaction.

[0059] (Reduction of catalyst) A 300 mL stainless steel reactor equipped with a nitrogen bubbling nozzle was charged with 54.94 g of the distilled and purified raw material compound represented by formula (2a), 8.24 g of Cu-Zn-Al catalyst (E-01X, manufactured by JGC Catalysts and Chemicals Co., Ltd.), and 120.86 g of tetrahydrolinanol (manufactured by Tokyo Chemical Industry Co., Ltd.). The atmosphere in the reactor was replaced with nitrogen and H2 gas three times each, after which the system was pressurized with H2 gas and the catalyst was reduced at 150 °C and 2 MPa for 1 hour. A trap was installed in the exhaust gas line, and the pressure was reduced to 0 MPa while maintaining the temperature at 150 °C. A small amount of nitrogen gas was then introduced through the nitrogen bubbling nozzle to remove the reduced water from the reaction solution. The trapped volume was 6.29 g.

[0060] (Obtaining dimethanol by hydrogenation reaction) Subsequently, the atmosphere in the reactor was replaced with H2 gas three times, and then the system was pressurized with H2 gas and the hydrogenation reaction was carried out at 215°C and 8.0 MPa. Tetrahydrolinanol was used as the solvent for the hydrogenation reaction. During the reaction, sampling was carried out every 5 or 10 hours. The sample solution was diluted with acetone, and the catalyst was filtered through a membrane filter with a pore size of 0.2 μm. Then, gas chromatography analysis and GC-MS analysis were performed to quantitatively analyze the target compound represented by the above formula (1a) as the main product, as well as the ester compound (intermediate) represented by the above formula (3a) and the transesterification compound (by-product) represented by the above formula (4d) with a molecular weight of 378. The quantitative analysis was performed using analytical column 2 (InertCapWAX). After 50 hours, the amount of the intermediate represented by formula (3a) was 0.50% (= intermediate represented by formula (3a) / (all components other than tetrahydrolinalool and acetone) × 100). The amount of the by-product represented by formula (4d) was 0.00% (= by-product represented by formula (4d) / (all components other than tetrahydrolinalool and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 47.96 g of the target compound represented by formula (1a) (substrate conversion rate 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%)), and the yield of the target compound was 97.50% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 mL three-necked eggplant flask equipped with a thermometer, a nitrogen bubbling nozzle, and a stirrer (distillation plate number 1, distillation temperature 170-180 °C, vacuum 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The main fraction containing the target compound represented by formula (1a) was 45.05 g, and the dimethanol purity was 99.53% (= target compound represented by formula (1a) / (all components other than acetone) × 100)). The distillation yield was 93.50% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX). The amount of the intermediate represented by formula (3a) was 0.48% (= intermediate represented by formula (3a) / (all components other than acetone) × 100). The amount of the by-product represented by formula (4d) was 0.00% (=by-product represented by formula (4d) / (all components other than acetone)×100).

[0061] Example 4 The hydrogenation reaction was carried out in the same manner as in Example 3, except that the trapped amount in the catalyst reduction was adjusted to 5.22 g and the hydrogenation reaction temperature was set to 225°C. After 20 hours, the amount of the intermediate represented by formula (3a) was 0.66% (= intermediate represented by formula (3a) / (all components other than tetrahydrolinalool and acetone) × 100). The amount of the by-product represented by formula (4d) was 0% (= by-product represented by formula (4d) / (all components other than tetrahydrolinalool and acetone) × 100). After completion of the reaction, the reaction solution was analyzed by gas chromatography using analytical column 1 (InertCap1), and it was confirmed that the reaction solution contained 47.88 g of the target compound represented by formula (1a) (substrate conversion rate: 100% (= (charged raw material compound - remaining raw material compound) / charged raw material compound) × 100%), and dimethanol yield: 97.34% (= target compound / charged raw material compound × 100%)). The reaction mixture was further purified by simple distillation using a 300 ml three-necked eggplant flask equipped with a thermometer, a N2 bubbling nozzle, and a stirrer (distillation plate number: 1, distillation temperature: 170-180 °C, vacuum: 2 torr). After purification, gas chromatography analysis was performed using analytical column 1 (InertCap1). The main fraction containing the target compound represented by formula (1a) was 43.64 g, and the dimethanol purity was 99.51% (= target compound represented by formula (1a) / (all components other than acetone) × 100)). The distillation yield was 90.70% (= target compound obtained / target compound charged × 100%). Furthermore, analysis was performed using analytical column 2 (InertCapWAX). The amount of the intermediate represented by formula (3a) was 0.50% (= intermediate represented by formula (3a) / (all components other than acetone) × 100). The amount of the by-product represented by formula (4d) was 0.00% (=by-product represented by formula (4d) / (all components other than acetone)×100). By increasing the hydrogenation reaction temperature, the reaction rate increased, improving productivity. In addition, no by-product represented by formula (4d) was observed, and high product purity was obtained.

[0062] The reaction conditions and results of the reactions in Examples 3 and 4 are shown in Table 2.

[0063] [Table 2]

[0064] This application is based on a Japanese patent application (Patent Application No. 2021-067275) filed on April 12, 2021, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0065] According to the production method of the present invention, a dimethanol compound having a norbornane skeleton, which is useful as a paint additive, adhesive, resin raw material, etc., can be produced in an industrially advantageous manner.

Claims

1. A method for producing a target compound represented by the following formula (1): The method includes a step (A) of subjecting a mixed liquid containing a raw material compound represented by the following formula (2) and a solvent to hydrogenation reduction in the presence of a catalyst having hydrogenation ability, The production method, wherein the solvent is a linear or branched secondary alcohol or a tertiary alcohol. 【Chemical 1】 (In the formula (1), R is H, CH ３ , or C ２ H ５ Represents.) 【Chemistry 2】 (In the formula (2), R is H, CH ３ , or C ２ H ５ Represents R １ is CH ３ , C ２ H ５ , C ３ H ７ , C ４ H ９ Represents.)

2. The method according to claim 1, wherein the boiling point of the solvent is 100 to 230°C.

3. The method according to claim 1 or 2, wherein the solvent is represented by the following formula (a): 【Chemistry 3】 (In the formula (a), R １ is H or CH ３ Represents R ２ is CH ３、 C ２ H ５、 C ３ H ７ or C ４ H ９ Represents R ３ is C ３ H ７ , C ４ H ９ , C ５ H １１、 C ６ H １３、 C ７ H １５、 C ８ H １７、 C ９ H １９、 C １０ H ２１、 C １１ H ２３、 or C １２ H ２５ Represents.)

4. The method according to any one of claims 1 to 3, wherein the content of the intermediate represented by the following formula (3) in the target compound is 0.5 mass% or less: 【Chemistry 4】 (Wherein, R is H, CH ３ , or C ２ H ５ Represents R １ is CH ３ , C ２ H ５ , C ３ H ７ , C ４ H ９ Represents.)

5. The method according to any one of claims 1 to 4, wherein the content of a by-product represented by the following formula (4) in the target compound is 0.5 mass% or less: 【Chemistry 5】 (Wherein, R is H, CH ３ , or C ２ H ５ Represents R ２ is C ４ H ９ , C ５ H １１ , C ６ H １３ , C ７ H １５ , C ８ H １７ , C ９ H １９ , C １０ H ２１ , C １１ H ２３ , C １２ H ２５ , C １３ H ２７ , C １４ H ２９ Represents.)

6. The method according to any one of claims 1 to 5, wherein the solvent is 2-octanol and / or tetrahydrolinanol.

7. 7. The production method according to claim 1, wherein in the step (A), the catalyst is activated at a first temperature and under a first pressure, and after the activation, the raw material compound is hydrogenated at a second temperature and under a second pressure.

8. The method according to claim 7 , wherein the second pressure is greater than 5 MPa and not greater than 20 MPa.

9. The manufacturing method according to claim 7 or 8, wherein the second pressure is greater than 5 MPa and equal to or less than 8 MPa.

10. The method according to claim 9, wherein the solvent is a linear or branched tertiary alcohol.

11. The method of claim 10, wherein the solvent is tetrahydrolinanol.

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