Method for producing cyclobutanediol skeleton compound

Abstract

To provide a process in which a high cis: trans ratio cyclobutanediol skeleton compound can stably be obtained.SOLUTION: By performing a catalytic hydrogenation reaction in a solid phase state in the presence of a metal catalyst without adding a solvent using at least one compound selected from the group of cyclobutanedione skeleton compound, cyclobutane ketol skeleton compound, and cyclobutanediol skeleton compound as a raw material, and an isomerization reaction in cyclobutanediol skeleton compound, a cyclobutanediol skeleton compound having a cis: trans ratio of 1.5: 1 to 5000: 1 is produced.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Cyclobutanediol skeleton compounds, such as 2,2,4,4-tetramethylcyclobutane-1,3-diol (hereinafter referred to as TMCBD), are used in the production of various polymer materials. For example, polyesters derived from dicarboxylic acids and TMCBD have high glass transition temperatures and excellent weather resistance and hydrolytic stability when compared with similar polyesters produced from other commonly used polyester-forming diols. The stereoisomers of the hydroxyl group of TMCBD include cis and trans isomers, and the cis:trans ratio of TMCBD obtained by catalytic hydrogenation of 2,2,4,4-tetramethylcyclobutane-1,3-dione (hereinafter, TMCBK) is often in the range of about 1:1 to about 1.5:1. The cis:trans ratio is known to affect important properties of polyesters having TMCBD, and stable control of the cis:trans ratio is important because it leads to stable quality of polyesters. As a method for adjusting the cis:trans ratio of TMCBD, there have been reports of isomerization alone without producing net TMCBD. In a liquid phase, a raw material with a cis:trans ratio of 0:1 to 1.5:1 is isomerized into products with different cis:trans ratios. However, since this method involves isomerization in a state where the raw material is completely dissolved in a solvent, the cis:trans ratio can only increase to about 1.5:1 at most (Patent Document 1).

[0003] There are also reports of catalytic hydrogenation of TMCBK to TMCBD at a reaction temperature higher than the dew point of TMCBD in the gas phase. However, this method also results in a low efficiency production process, with the cis:trans ratio of the resulting TMCBD being about 1:1 to about 1.6:1, which is not much different from that of a completely dissolved system, and requiring 100 to 500 mol of hydrogen (Patent Document 2).

[0004] Furthermore, as a method for increasing the cis:trans ratio of TMCBD, there have been reports of the use of reactive crystallization, in which the cis isomer is precipitated during the reaction. In this method, water, a hydrocarbon, or a mixture thereof is used as a solvent, and TMCBK is brought into contact with hydrogen in the presence of a ruthenium catalyst to precipitate the resulting cis-TMCBD, resulting in TMCBD with a high cis:trans ratio being obtained in the reaction system. However, as an example, cis-TMCBD is obtained by filtering the precipitated cis-TMCBD and rinsing the filter cake with a solvent in which cis-TMCBD dissolves, resulting in a large amount of solvent being used in the process from the reaction to the recovery of cis-TMCBD, and this cannot be said to be an environmentally friendly process from the perspective of green chemistry (Patent Documents 3-4).

[0005] On the other hand, from the perspective of green and sustainable chemistry, there have been reports of hydrogenation and Suzuki coupling in a solid phase where the raw materials, intermediates, products, and catalysts are solid, without using solvents. In hydrogenation, good hydrogenation reactions have been confirmed for unsaturated hydrocarbons, azide derivatives, benzyl ethers, etc., in the presence of a palladium catalyst and at atmospheric partial pressure of hydrogen (Non-Patent Document 1).

[0006] To date, there have been no studies on the reduction of cyclobutanedione compounds such as TMCBK using a ruthenium catalyst in a solid phase without the use of a solvent. From the perspective of green chemistry, it is necessary to develop an environmentally friendly manufacturing process for cyclobutanediol compounds such as TMCBD, and there has been a demand for a process that can stably obtain cyclobutanediol compounds with a high cis:trans ratio. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2012 / 078439 [Patent Document 2] International Publication No. 2012 / 078384 [Patent Document 3] International Publication No. 2016 / 094478 [Patent Document 4] International Publication No. 2016 / 094479 [Non-patent literature]

[0008] [Non-Patent Document 1] Tetrahedron 67 (2011) 8628-8634 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to develop a process for producing a cyclobutanediol skeleton compound that is environmentally friendly from the viewpoint of green chemistry and that can stably produce a cyclobutanediol skeleton compound with a high cis:trans ratio. [Means for solving the problem]

[0010] The present inventors have found that a cyclobutanediol skeleton compound with a high cis:trans ratio can be stably obtained by carrying out a catalytic hydrogenation reaction from a cyclobutanedione skeleton compound to a cyclobutanediol skeleton compound, or by carrying out a cis-trans isomerization of a cyclobutanediol skeleton compound in the presence of a metal catalyst in a solid phase state without using a solvent. Based on the above findings, the present invention has been completed. That is, the present invention is as follows.

[0011] [1] A method for producing a cyclobutanediol skeleton compound having a cis:trans ratio of 1.5:1 to 5000:1, by using at least one compound selected from the group consisting of cyclobutanedione skeleton compounds, cyclobutane ketol skeleton compounds, and cyclobutanediol skeleton compounds as a raw material, and carrying out a catalytic hydrogenation reaction in a solid phase in the presence of a metal catalyst and without adding a solvent, and an isomerization reaction in the cyclobutanediol skeleton compound.

[0012] [2] The method for producing a cyclobutanediol skeleton compound according to item [1], wherein the cyclobutanedione skeleton compound is a cyclobutanedione skeleton compound represented by general formula (1). TIFF0007631923000001.tif3243 Here, R 1 , R 2 , R 3 , and R 4 are independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 4 to 30 carbon atoms; R 1 , R 2 , R 3 and R 4 may be bonded to each other to form a cyclic structure.

[0013] [3] The method for producing a cyclobutanediol skeleton compound according to item [1] or [2], wherein the metal catalyst is a catalyst containing at least one metal selected from Groups 8, 9, 10, and 11 of the periodic table.

[0014] [4] The method for producing a cyclobutanediol skeleton compound according to any one of items [1] to [3], wherein the metal catalyst is a catalyst containing Ru, Rh, or Ni.

[0015] [5] The method for producing a cyclobutanediol skeleton compound according to any one of items [1] to [4], wherein the metal catalyst is a metal salt, a metal oxide, a metal element, a metal fine powder, a porous metal catalyst, or a metal-supported catalyst, and the support of the metal-supported catalyst is at least one support selected from the group consisting of oxides, hydrates, carbon, and cellulose.

[0016] [6] The method for producing a cyclobutanediol skeleton compound according to any one of items [1] to [5], wherein the partial pressure of hydrogen in the reaction is in the range of 0.02 to 50 MPa and the reaction temperature is in the range of 10 to 150°C. Effect of the Invention

[0017] The method for producing a cyclobutanediol skeleton compound according to the present invention can obtain a cyclobutanediol skeleton compound having a higher cis-isomer ratio than conventional methods under mild reaction conditions, and since no reaction solvent is used, the method can be said to be an environmentally friendly process from the perspective of green chemistry. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. Note that the present invention is not limited to the following embodiment.

[0019] The method for producing a cyclobutanediol skeleton compound of the present invention is characterized in that the cis:trans ratio of the cyclobutanediol skeleton compound is higher than that achieved in a solution system by carrying out a catalytic hydrogenation reaction and an isomerization reaction of the cyclobutanediol skeleton compound in a solid phase state without adding a solvent to the raw material and the metal catalyst.

[0020] As the raw material, at least one compound selected from the group consisting of cyclobutanedione skeleton compounds, cyclobutane ketol skeleton compounds, and cyclobutanediol skeleton compounds can be used without any particular limitation. For example, the cyclobutanedione skeleton compound is a cyclobutanedione skeleton compound represented by general formula (1). TIFF0007631923000002.tif3243 Here, R 1 , R 2 , R 3 , and R 4 are independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 4 to 30 carbon atoms; R 1 , R 2 , R 3 and R 4 may be bonded to each other to form a cyclic structure.

[0021] The metal of the metal catalyst is at least one metal selected from Groups 8, 9, 10, and 11 of the periodic table. Preferably, it is Ru, Rh, or Ni. Particularly preferably, it is Ru. The state of the metal catalyst is not particularly limited, and may be a metal salt, metal oxide, metal element, or metal fine powder. These metal catalysts may be used as they are or in a porous form, or may be supported on a carrier.

[0022] The carrier may be an oxide, a hydrate, carbon, cellulose, or the like, and at least one of these may be used. Examples of oxides include silica, alumina, titania, ceramics, zirconia, niobia, and zeolite. Examples of hydrates include hydroxyapatite, niobic acid, zirconic acid, tungstic acid, and titanic acid. Examples of carbon include activated carbon, carbon black, graphite, graphene, graphene oxide, and carbon nanotubes.

[0023] The amount of metal supported in the metal catalyst is 0.1 to 15% by weight, preferably 0.2 to 10% by weight. The metal catalyst may be in a dry state or in a wet state with water etc. The amount of water in the wet state is 1 to 200% by weight, preferably 5 to 100% by weight.

[0024] The catalyst concentration may be changed within a wide range, but is adjusted to the range of 0.001 to 50 mol % (molar amount of catalyst metal relative to the mol amount of raw material), preferably 0.01 to 20 mol %, and more preferably 0.1 to 10 mol %.

[0025] In an embodiment of the present invention, the raw material and the metal catalyst are charged into a reaction apparatus, hydrogen is substituted in a solid phase without adding a solvent, and the reaction is carried out at a predetermined reaction temperature and mixing conditions. The reactor may be any vessel capable of gas replacement, and flasks, autoclaves, etc. may be used. Rotary evaporators, which rotate and mix the inside of the vessel, and the "rocking mixer" manufactured by Aichi Electric Co., Ltd. may also be used, and a method of feeding hydrogen into a column-type fixed bed in which the raw material and catalyst are mixed in advance and packed is also possible. In addition, fluidized bed reactors capable of semi-continuously handling solids, Nauta mixers, ribbon blenders, and Kobelco Eco-Solutions Co., Ltd.'s "SV mixer" and "PV mixer" may also be used.

[0026] The raw materials and the metal catalyst may be charged separately or in a premixed state. In order to prevent a sudden load on the stirring power of the reactor, they may be charged while the stirring of the reactor is in operation.

[0027] The hydrogen replacement method in the reactor includes a method of replacing by introducing a large amount of hydrogen, a method of repeatedly pressurizing with hydrogen or an inert gas and purging, a method of repeatedly introducing hydrogen after depressurizing the reactor, etc. In the embodiment of the present invention, since the reactor is in a solid phase state without adding a solvent, there is no concern about evaporation of the solvent, etc., and therefore the method of repeatedly introducing hydrogen after depressurizing the reactor is preferable.

[0028] The hydrogen in the reactor may be in a mixed state with an inert gas, and the partial pressure of hydrogen is in the range of 0.02 to 50 MPa, preferably 0.05 to 5 MPa, and more preferably 0.08 to 0.98 MPa. The reaction temperature is in the range of 10 to 150°C, preferably 30 to 100°C, and more preferably 50 to 80°C. The mixing conditions are such that the raw material and the metal catalyst are kept in a sufficiently mixed state. If the raw materials are charged in a premixed state, there is no need to mix them in the reactor.

[0029] After the reaction, the catalyst can be easily removed from the reaction mixture by dissolving the reaction mixture in a solvent to make it heterogeneous and filtering it. The filtered catalyst may be repeatedly used in catalytic hydrogenation and isomerization without further treatment. The catalyst may also be washed with water and repeatedly used in the initial wet state with water.

[0030] The reaction mixture can be dissolved in at least one solvent selected from water, alcohol, ether, hydrocarbon, ketone, and ester. For example, water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-ethylhexanol, diethyl ether, diisopropyl ether, tetrahydrofuran, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, isobutyl isobutyrate, and mixtures thereof. In view of availability and ease of operation, water, methanol, 2-propanol, acetone, and ethyl acetate are preferred.

[0031] As a method for removing the catalyst from the reaction mixture after the reaction other than the above, a conventional method such as distillation, sublimation, melting, etc. can also be used, although it depends on the physical properties of the compound. EXAMPLES

[0032] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0033] [Example 1] (Example of catalytic hydrogenation reaction under atmospheric pressure) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM We used the PPM-5512 model. 7.14 mmol of TMCBK as the raw material and 1.5 g of 5 wt% Ru / C (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as the catalyst (Ru / C catalyst has a ruthenium content of 1 / 10 mol of the raw material) were placed in a 120 mL test tube. After degassing the inside of the test tube, a hydrogen gas balloon was attached and replaced with a hydrogen gas atmosphere. The reaction temperature was set to 60°C and the reaction was carried out by stirring at a stirring speed of 300 rpm for 6 hours.

[0034] (Post-reaction treatment) Then, 40 mL of ethyl acetate was added to the obtained reaction product to dissolve the raw materials, products, etc., and the reaction filtrate from which the catalyst Ru / C had been removed was obtained by filtering using a membrane filter (ADVANTEC, DISMIC (registered trademark), 13HP020AN, pore size 0.20 μm). The catalyst Ru / C used in the reaction was washed with 10 mL of ethyl acetate separately, and the washing liquid was collected. The washing liquid was combined with the reaction filtrate obtained earlier, and the ratio of the raw materials to the reaction products was calculated by measuring the ratio by gas chromatography (Shimadzu Corporation, GC-2030). The reaction products include the raw material TMCBK, the monoreductant TMCBO, the direductant with the cis isomer being cis-TMCBD, the trans isomer being trans-TMCBD, and the by-products with the cyclobutane skeleton ring-opened, "others," and the GC compositions are shown in the table below. The ratio of the cis isomer to the trans isomer of TMCBD is also shown in the table.

[0035] [Examples 2 to 3] The same procedures as in Example 1 were carried out except that the reaction temperatures were changed to 70°C and 80°C, respectively.

[0036] [Examples 4 to 6] The same procedure as in Example 1 was repeated except that the catalyst in Example 1 was changed to 5 wt% Ru / Al2O3 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and the reaction temperatures were 60°C, 70°C, and 80°C, respectively. The results of Examples 1 to 6 are shown in Table 1 below. Table 1 TIFF0007631923000003.tif78138 The results of Examples 1 to 6 show that TMCBD can be quantitatively obtained from TMCBK by performing catalytic hydrogenation in a solid phase without adding a solvent, and that TMCBD has a high cis ratio of about 4 to about 30.

[0037] [Example 7] (Example of catalytic hydrogenation reaction under pressure) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM The PPV-4460 model was used. 1.96 mmol of TMCBK as raw material and 0.13 g of 50 wt% water-containing 5 wt% Ru / C (A-type / manufactured by N.E. Chemcat) as catalyst (Ru / C catalyst has a ruthenium content of 1 / 60 mol of the raw material) were put into a 42 mL reaction tube. After that, a gas line was connected and the atmosphere was replaced with hydrogen gas. The partial pressure of hydrogen was set to 0.8 MPa, the reaction temperature was set to 50°C, and the reaction was carried out with stirring at a stirring speed of 600 rpm for 4 hours. The post-treatment after the reaction was carried out in the same manner as in Example 1.

[0038] [Examples 8 to 10] The same procedures as in Example 7 were carried out except that the reaction temperatures were changed to 60°C, 70°C, and 80°C, respectively.

[0039] [Comparative Example 1] (Example of catalytic hydrogenation reaction under pressure in methanol) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM The PPV-4460 model was used. 7.82mmol of TMCBK as raw material, 0.53g of 50wt% water-containing 5wt% Ru / C (A-type / manufactured by N.E. Chemcat) as catalyst (Ru / C catalyst has 1 / 60mol of the amount of ruthenium in the raw material), and 40mL of methanol as reaction solvent were put into a 190mL reaction tube. After that, a gas line was connected and the atmosphere was replaced with hydrogen gas. Then, the partial pressure of hydrogen was set to 0.8MPa, the reaction temperature was set to 80℃, and the reaction was carried out with stirring at a stirring speed of 600rpm for 4 hours. Thereafter, the obtained reaction solution was filtered through a membrane filter (manufactured by ADVANTEC, DISMIC (registered trademark), 13HP020AN, pore size 0.20 μm) to obtain a reaction filtrate from which the catalyst Ru / C had been removed. The subsequent operations were carried out in the same manner as in Example 1.

[0040] [Comparative Examples 2 to 3] The same procedures as in Comparative Example 1 were carried out except that the reaction solvents were changed to isopropyl alcohol and ethyl acetate, respectively. The results of Examples 7 to 10 and Comparative Examples 1 to 3 are shown in Table 2 below.

[0041] Table 2 TIFF0007631923000004.tif93148

[0042] A comparison of Examples 7 to 10 and Comparative Examples 1 to 3 shows that the cis ratio in TMCBD increases when catalytic hydrogenation is carried out in a solid phase without adding a solvent.

[0043] [Example 11] (Example of isomerization under pressure using Ru / C) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM The PPV-4460 model was used. 1.96 mmol of TMCBD before isomerization and 0.13 g of 50 wt% water-containing 5 wt% Ru / C (A-type / N.E. Chemcat) catalyst (Ru content in catalyst Ru / C is 1 / 60 mol of TMCBD before isomerization) were put into a 42 mL reaction tube. After that, a gas line was connected and the atmosphere was replaced with hydrogen gas. Then, the hydrogen partial pressure was set to 0.8 MPa, the reaction temperature was set to 60°C, and the reaction was carried out with stirring at a stirring speed of 600 rpm for 5.6 hours. The post-treatment after the reaction was carried out in the same manner as in Example 1.

[0044] [Example 12] (Example of isomerization under pressure using Ru / Al2O3) The same procedure was carried out as in Example 10, except that the catalyst was changed to 5 wt% Ru / Al2O3 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The TMCBD composition before isomerization and the results of Examples 11 and 12 are shown in Table 3 below.

[0045] Table 3 TIFF0007631923000005.tif41129

[0046] The results of Examples 10 and 11 show that the cis ratio of TMCBD increases when the isomerization reaction of a cyclobutanediol skeleton compound is carried out in a solid phase without adding a solvent.

[0047] [Example 13] (An example of catalytic hydrogenation of dispiro[5.1.5.1]tetradecane-7,14-dione (DSTDK) using Ru / C) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM We used the PPM-5512 model. 7.13 mmol of DSTDK as the raw material and 1.50 g of 5 wt% Ru / C (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as the catalyst (Ru / C catalyst has a ruthenium content of 1 / 10 mol of the raw material) were placed in a 120 mL reaction tube. After degassing the inside of the test tube, a hydrogen gas balloon was attached and replaced with a hydrogen gas atmosphere. The reaction temperature was set to 70°C and the reaction was carried out with stirring at a stirring speed of 300 rpm for 6 hours. Then, 40 mL of ethyl acetate was added to the obtained reaction product to dissolve the raw materials, products, etc., and the reaction filtrate from which the catalyst Ru / C had been removed was obtained by filtering using a membrane filter (manufactured by ADVANTEC, DISMIC (registered trademark), 13HP020AN, pore size 0.20 μm). The catalyst Ru / C used in the reaction was washed with 10 mL of ethyl acetate separately, and the washing liquid was collected. The washing liquid was combined with the reaction filtrate obtained earlier, and the ratio of the raw materials to the reaction products was calculated by measuring the ratio by gas chromatography (manufactured by Shimadzu Corporation). The reaction products were the raw material DSTDK, the monoreductant DSTDO, the direductant cis-DSTDD, the trans-DSTDD, and others as by-products in which the cyclobutane skeleton was opened, and the GC composition was shown in the table below.

[0048] [Example 14] (Example of catalytic hydrogenation reaction under pressure using Ru / Al2O3) The same procedure was carried out as in Example 13, except that the catalyst was changed to 5 wt% Ru / Al2O3 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The results of Examples 13 and 14 are shown in Table 4 below.

[0049] Table 4 TIFF0007631923000006.tif41146

[0050] The results of Examples 13 and 14 show that DSTDD can be quantitatively obtained from DSTDK by performing catalytic hydrogenation in a solid phase without adding a solvent, and that DSTDD has a high cis ratio of about 7 to about 155.

[0051] [Example 15] (Example of catalytic hydrogenation reaction using Rh / C at atmospheric pressure) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM We used the PPM-5512 model. 7.14 mmol of TMCBK before isomerization and 0.40 g of 50 wt% water-containing 5 wt% Rh / C (manufactured by N.E. Chemcat) catalyst (the rhodium content in the catalyst Rh / C is 1 / 60 mol of that of TMCBD before isomerization) were placed in a 120 mL reaction tube. After degassing the inside of the test tube, a hydrogen gas balloon was attached and the atmosphere was replaced with hydrogen gas. The reaction temperature was set to 80°C and the reaction was carried out with stirring at a stirring speed of 200 rpm for 6 hours. The post-treatment after the reaction was carried out in the same manner as in Example 1.

[0052] [Example 16] (Example of isomerization under atmospheric pressure using sponge nickel) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM We used the PPM-5512 model. 7.14 mmol of TMCBD before isomerization and 0.42 g (1 / 10 mol of TMCBD before isomerization) of sponge nickel (Tokyo Chemical Industry Co., Ltd.) as a catalyst were placed in a 120 mL reaction tube. After degassing the inside of the test tube, a hydrogen gas balloon was attached and replaced with a hydrogen gas atmosphere. The reaction temperature was set to 80°C and the reaction was carried out with stirring at a stirring speed of 200 rpm for 6 hours. The post-treatment after the reaction was carried out in the same manner as in Example 1.

[0053] [Example 17] (Example of isomerization by Rh / C under atmospheric pressure) The reaction equipment was the "Personal Organic Synthesis Equipment ChemiStation" manufactured by Tokyo Rikakikai Co., Ltd. TM We used the PPM-5512 model. 7.14 mmol of TMCBD before isomerization and 0.40 g of 50 wt% water-containing 5 wt% Rh / C (manufactured by N.E. Chemcat) catalyst (the rhodium content in the catalyst Rh / C is 1 / 60 mol of the amount of TMCBD before isomerization) were placed in a 120 mL reaction tube. After degassing the inside of the test tube, a hydrogen gas balloon was attached and the atmosphere was replaced with hydrogen gas. The reaction temperature was set to 80°C and the reaction was carried out with stirring at a stirring speed of 200 rpm for 6 hours. The post-treatment after the reaction was carried out in the same manner as in Example 1. The TMCBD composition before isomerization and the results of Examples 15 to 16 are shown in Table 5 below.

[0054] Table 5 TIFF0007631923000007.tif52133

[0055] The results of Examples 15 to 17 show that even when a metal catalyst other than Ru is used, the cis ratio in TMCBD increases by carrying out the reaction in a solid phase without adding a solvent. [Industrial Applicability]

[0056] The cyclobutanediol skeleton compound having a high cis:trans ratio obtained by the method for producing a cyclobutanediol skeleton compound of the present invention can be used as a raw material for polyesters having high stability and consistent quality in terms of glass transition temperature, impact strength, weather resistance, and hydrolysis stability.

Claims

1. A method for producing a cyclobutanediol skeleton compound having a cis:trans ratio of 1.5:1 to 155.5:1, by using at least one compound selected from the group consisting of a cyclobutanedione skeleton compound, a cyclobutane ketol skeleton compound, and a cyclobutanediol skeleton compound as a raw material, and carrying out a catalytic hydrogenation reaction in a solid phase state in the presence of a metal catalyst without adding a solvent, and an isomerization reaction in the cyclobutanediol skeleton compound.

2. The method for producing a cyclobutanediol skeleton compound according to claim 1, wherein the cyclobutanedione skeleton compound is a cyclobutanedione skeleton compound represented by general formula (1): Here, R １ , R ２ , R ３ and R ４ are independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 4 to 30 carbon atoms; R １ , R ２ , R ３ and R ４ may be bonded to each other to form a cyclic structure.

3. 3. The method for producing a cyclobutanediol skeleton compound according to claim 1, wherein the metal catalyst is a catalyst containing at least one metal selected from Groups 8, 9, 10, and 11 of the periodic table.

4. The method for producing a cyclobutanediol skeleton compound according to any one of claims 1 to 3, wherein the metal catalyst is a catalyst containing Ru, Rh, or Ni.

5. The method for producing a cyclobutanediol skeleton compound according to any one of claims 1 to 4, wherein the metal catalyst is a metal salt, a metal oxide, a metal element, a metal fine powder, a porous metal catalyst, or a metal-supported catalyst, and the support of the metal-supported catalyst is at least one support selected from the group consisting of oxides, hydrates, carbon, and cellulose.

6. The method for producing a cyclobutanediol skeleton compound according to any one of claims 1 to 5, wherein the partial pressure of hydrogen in the reaction is in the range of 0.02 to 50 MPa, and the reaction temperature is in the range of 10 to 150°C.

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