TW201418211A - 1,4-tetralindicarboxylic acid dialkyl ester and method of producing same - Google Patents

Abstract

The invention provides a 1, 4-tetralindicarboxylic acid dialkyl ester represented by formula (1). (In formula (1), each of R and R' represents an alkyl group with a carbon number of 1 to 10, wherein R and R' may be the same or different.)

Description

Dialkyl 1,4-tetrahydronaphthalene dicarboxylate and process for producing same

The present invention relates to a 1,4-tetrahydronaphthalene dicarboxylic acid dialkyl ester which is a novel tetrahydronaphthalene derivative and a process for producing the same.

The dialkyl naphthalene dicarboxylate has a majority of structural isomers depending on the position of substitution of the carboxyl group for the tetrahydronaphthalene ring. For example, Patent Documents 1 and 2 disclose 1,5-tetrahydronaphthalene dicarboxylate, 1,8-tetrahydronaphthalene dicarboxylate, 2,6-tetrahydronaphthalene dicarboxylic acid dialkyl. ester. Further, Non-Patent Document 1 discloses a dialkyl 5,8-tetrahydronaphthalene dicarboxylate or a dialkyl 5,6-tetrahydronaphthalene dicarboxylate.

As a method for producing tetraalkyl naphthalene dicarboxylate, Patent Documents 1 and 2 disclose a method of derivatizing a naphthalene ring into a tetrahydronaphthalene ring by hydrogenation of dimethyl naphthalate. The naphthalenedicarboxylic acid dialkyl ester of the raw materials disclosed in these documents is equivalent to one of the two substituents bonded to the 1 to 4 position of the naphthalene ring, and the other is bonded to the 5 to 8 position, and For the specific case, only the two substituents are disclosed in the 1,5, 1,8, and 2,6 positions of the naphthalene ring. When the naphthalene dicarboxylic acid dialkyl ester is hydrogenated, even if any one of the 1 to 4 or 5 to 8 positions of the naphthalene ring is hydrogenated, the same dimethyl tetrahydronaphthalene dicarboxylate can be obtained. Structure.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-278836

[Patent Document 2] Japanese Patent No. 3210148

[Non-patent literature]

[Non-Patent Document 1] Journal of Organic Chemistry, 1962, 27, p. 5-13

However, the dialkyl 1,4-tetrahydronaphthalene dicarboxylate (hereinafter sometimes referred to as "1,4-TDCE") having a substituent bonded at the 1,4 position of the tetrahydronaphthalene ring is not in the above-mentioned A document or the like is disclosed. Further, in order to hydrogenate a 1,4-naphthalene dicarboxylic acid dialkyl ester represented by the following formula (2) and obtain a dialkyl 1,4-tetrahydronaphthalene dicarboxylate (hereinafter sometimes referred to as "1,4- NDCE"), the 5-8 position of the naphthalene ring must be selectively hydrogenated, but such a hydrogenation method is unknown.

On the other hand, if the above-mentioned 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester can be produced with good efficiency, it is expected to be applied to various uses such as various resin raw materials, liquid crystal compositions, polymer modifiers, and pharmaceutical intermediates.

The present invention has been made in view of the above circumstances, and aims to provide a raw material which is considered to be a resin such as polyester, polycarbonate, polythenimine or polyamine; a liquid crystal composition; a polymer modifier; a pharmaceutical intermediate, etc. It is a novel novel 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester, and a process for producing the same.

The inventors of the present invention have diligently studied, and as a result, unexpectedly found that 1,4-TDCE can be synthesized by hydrogenating 1,4-NDCE in a solvent in the presence of a noble metal catalyst, and the present invention has been completed.

That is, the present invention is as follows.

[1] a dialkyl 1,4-tetrahydronaphthalene dicarboxylate represented by the formula (1);

(In the formula (1), R and R' represent an alkyl group having 1 to 10 carbon atoms, and R and R' may be the same or different).

[2] A process for producing a dialkyl 1,4-tetrahydronaphthalene dicarboxylate, comprising the step of hydrogenating a 1,4-naphthalene dicarboxylate in a solvent in the presence of a noble metal catalyst.

[3] The method for producing a dialkyl 1,4-tetrahydronaphthalene dicarboxylate according to [2], wherein the noble metal catalyst is selected from the group consisting of rhodium catalysts, rhodium catalysts, and palladium catalysts. At least one of the groups.

[4] The method for producing a 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester according to [2], wherein the noble metal catalyst is selected from the group consisting of a ruthenium catalyst and a ruthenium catalyst. 1 species.

[5] The method for producing a 1,4-tetrahydronaphthalene dicarboxylic acid dialkyl ester according to [2], wherein the hydrogenation is carried out at a reaction temperature of from 0 to 100 °C.

[6] The method for producing a dialkyl 1,4-tetrahydronaphthalene dicarboxylate according to [2], wherein the hydrogenation is carried out in the presence of a solvent, and the solvent is used in an amount relative to the 1,4-naphthalene The dialkyl dicarboxylate is in the range of 0.5 to 8 in terms of a mass ratio.

According to the present invention, a novel tetrahydronaphthalene derivative 1,4-TDCE can be provided. 1,4-TDCE is considered to be used as a resin raw material such as polyester, polycarbonate, polyimine or polyamine, a liquid crystal composition, a polymer modifier, a pharmaceutical intermediate, etc., so that it is industrially Great meaning.

Fig. 1 is a FT-IR (KBr method) chart showing crystals obtained by recrystallizing the product of Example 1.

Fig. 2 is a chart showing the FT-IR (KBr method) of 1,4-naphthalene dicarboxylic acid dimethyl used as the starting material in Example 1.

Fig. 3 shows the results of precision mass analysis of the crystal obtained by recrystallizing the product of Example 1 by GC-TOF/MS.

Fig. 4 shows a ¹ H-NMR chart of the crystal obtained by recrystallizing the product of Example 1.

Fig. 5 shows a ¹³ C-NMR chart of the crystal obtained by recrystallizing the product of Example 1.

Figure 6 shows a dept135-NMR chart of the crystal obtained by recrystallizing the product of Example 1.

Fig. 7 shows a ¹³ C-ig-NMR chart of the crystal obtained by recrystallizing the product of Example 1.

Fig. 8 is a HMBC-NMR chart showing the crystal obtained by recrystallizing the product of Example 1.

Fig. 9 is a HMQC-NMR chart showing the crystal obtained by recrystallizing the product of Example 1.

Figure 10 shows an INADEQUATE-NMR chart of the crystal obtained by recrystallizing the product of Example 1.

Hereinafter, the form for carrying out the invention (hereinafter simply referred to as "this embodiment") will be described in detail. The following embodiments are illustrative of the present invention, and the present invention is not limited to the following. The present invention can be appropriately modified and implemented within the scope of the gist of the invention.

This embodiment provides a dialkyl 1,4-tetrahydronaphthalene dicarboxylate represented by the formula (1).

(In the formula (1), R and R' each represent an alkyl group having 1 to 10 carbon atoms, and R and R' may be the same or different.)

In the formula (1), R and R' each independently represent an alkyl group having 1 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, and anthracene group. Base, positive base, etc.

Among these, from the viewpoint of reactivity when used as a raw material of polyester or polycarbonate, both R and R' are preferably a methyl group.

The 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester of the present embodiment can be used, for example, by a step of hydrogenating a 1,4-naphthalene dicarboxylate in the presence of a noble metal catalyst in a solvent. A method for producing 4-dihydronaphthalene dicarboxylic acid dialkyl ester is obtained.

In the past, it has been difficult to selectively hydrogenate the raw materials, that is, the 5 to 8 positions of the alkyl 1,4-naphthalene dicarboxylate. However, the inventors of the present invention have diligently studied, and as a result, it has been unexpectedly found that if a hydrogenation reaction is carried out in a solvent in the presence of a noble metal catalyst, the 5 to 8 positions of the naphthalene ring can be selectively hydrogenated, and as a result, 1,4-tetrahydrogen can be obtained. Dialkyl naphthalene dicarboxylate. Although the reason is not certain, it is considered that a ring having an ester group having two electron-donating electron-attracting substituents is generally easier to hydrogenate, but from the viewpoint of steric hindrance, a ring having no substituent has high reactivity. In the present embodiment, it is estimated that the effect of the steric obstacle is remarkably exhibited, and it is unexpectedly possible to selectively hydrogenate the 5 to 8 positions (however, the effect of the embodiment is not limited thereto).

[1. Catalysts that can be used in the reaction]

Precious metal catalysts such as ruthenium catalyst (Ru), rhodium catalyst (Rh), palladium catalyst (Pd), platinum catalyst (Pt), ruthenium catalyst (Ir), ruthenium catalyst (Ru), The rhodium catalyst (Ph) and the palladium catalyst (Pd) are more preferable, and from the viewpoint of high selectivity of the hydrogenation reaction, the catalyst and the rhodium catalyst are more preferable, and from the viewpoint of higher yield, the rhodium catalyst is more desirable.

As the noble metal catalyst, it is preferred that the catalyst (supporting catalyst) obtained by supporting the noble metal on the support is preferable. The support is, for example, carbon, alumina, cerium oxide, zeolite or the like. Among these, carbon such as activated carbon is preferred from the viewpoint of availability or economy. By using the carrier catalyst, there is a table that can be used. The increase in area allows the use of the catalyst to be reduced, or the benefits of ease or safety.

The content of the noble metal in the catalyst is preferably 0.1 to 50% by mass, more preferably 1 to 10% by mass. Specifically, for example, a carbon-supporting catalyst containing 0.1 to 50% by mass of the noble metal catalyst, and more preferably 0.1 to 50% by mass selected from the group consisting of palladium, rhodium, and ruthenium. The carbon-supporting catalyst of either one of them is more preferably a carbon-supporting catalyst containing 0.1 to 50% by mass of any one selected from the group consisting of palladium, rhodium, and ruthenium. Further, the catalyst may be a dried product or a water-containing product. From the viewpoint of safety and the like, it is preferred to use a hydrated product. The water content in the catalyst is preferably from 10 to 80% by mass, more preferably from 40 to 60% by mass, from the viewpoint of ease of handling.

Commercially available products may be used as the catalyst, and those prepared by a known method such as an impregnation method may be used. For example, "5% Ru carbon powder type A (water-containing product)", "5% Ru carbon powder type B (water-containing product)", "5% Ru carbon powder type K (water-containing product) manufactured by NECHEMCAT Co., Ltd. "Ru carbon powder such as 5% Ru carbon powder R type (aqueous product)", "Ru alumina powder", "Ru black" or Ru alumina powder; "5% Rh carbon powder (aqueous product) "Rh carbon powder or Rh alumina powder such as "5% Rh alumina powder"; "5% Pd carbon powder PE type (aqueous product)", "5% Pd carbon powder STD type (aqueous product)" , "5% Pd carbon powder K type (water-containing product)", "5% Pd carbon powder NXA type (aqueous product)", "5% Pd carbon powder P type (aqueous product)", "5% Pd Carbon powder AER type (water-containing product), "5% Pd carbon powder KER type (water-containing product)", "5% Pd carbon powder type E (water-containing product)", "5% Pd carbon powder type B" (Hydrophilic product), "20% Pd carbon powder NX type (aqueous product)", "20% Pd carbon powder UR type (aqueous product)" "10% Pd carbon powder NX type (aqueous product)", "10% Pd carbon powder type K (water-containing product)", "10% Pd carbon powder PE type (water-containing product)", "10% Pd carbon powder OH type (aqueous product)", "10% Pd carbon" Pd carbon powder such as powder AE type (aqueous product) and "5% Pd alumina powder" Pd-alumina powder. Further, as described above, of course, a dried product can also be used.

The amount of the catalyst used is preferably from 0.05 to 5% by mass, more preferably from 0.1 to 3% by mass, based on the mass ratio of the noble metal to the 1,4-NDCE as the raw material. By using the amount of the catalyst in the above range, the reaction time can be suppressed for a short period of time, and the reaction can be promoted with good efficiency with a small amount of catalyst.

[2. Solvents that can be used in the reaction]

The solvent is not particularly limited as long as it does not interfere with the hydrogenation reaction. The solvent is, for example, an aliphatic hydrocarbon solvent such as hexane, heptane, octane, decane, decane or dodecane, methanol, ethanol, propanol, isopropanol, tert-butanol, ethylene glycol, glycerin, or the like. Alcohol solvent, diethyl ether, tetrahydrofuran, two An ether solvent such as an alkane.

The amount of the solvent to be used is not particularly limited, and is preferably in the range of 0.5 to 8 and more preferably in the range of 0.8 to 5, based on the mass ratio of 1,4-NDCE. By setting the mass ratio to the above range, the reaction can be easily controlled and efficiently performed, and the separation or recovery of the solvent becomes easier, which is preferable. For example, by setting the mass ratio of the solvent to 1,4-NDCE within the above range, the concentration of the reactant can be made high, so that the reaction efficiency is high and the productivity is excellent. On the other hand, in the normal case, the influence of the reaction heat increases at a high concentration, and the control of the reaction temperature or the like tends to be difficult, but this embodiment is not surprisingly possible, and the reaction control is also easy.

[3. Reaction conditions]

The hydrogenation reaction of the present embodiment is preferably carried out in a pressurized container such as an autoclave. The hydrogen pressure in the hydrogenation reaction is not particularly limited, and is preferably 1 to 8 MPa, more preferably 2 to 5 MPa. When the pressure of the hydrogen gas is in the above range, the positional selectivity to the 5-8 position of the naphthalene ring is further improved in the hydrogenation reaction, and 1,4-TDCE can be produced with higher efficiency.

The reaction temperature of the hydrogenation reaction is usually from 0 to 100 ° C, more preferably from 20 to 70 ° C, and more preferably from 25 to 45 ° C. By performing the hydrogenation reaction in the above temperature range, the positional selectivity at the 5 to 8 positions of the naphthalene ring is further improved in the hydrogenation reaction, and an appropriate reaction rate is obtained, so that 1,4-TDCE can be produced with higher efficiency.

[4. Refinement]

After the reaction is completed, for example, the catalyst is filtered off from the reaction mixture and the filtrate is recovered. Further, if necessary, the catalyst is washed with a solvent having a good washing efficiency (extraction efficiency) such as water, acetone, methanol or chloroform, and the washing liquid is recovered. The recovered washing liquid was combined with the filtrate as a mixed liquid. From the mixture, the solvent was distilled off, and 1,4-TDCE was taken out. Furthermore, it is also possible to use recrystallization, distillation, and column Purification by chromatography or the like.

The 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester of the present embodiment is preferably used as a resin raw material such as polyester, polycarbonate, polyimide or polyamine; liquid crystal composition; polymer modifier ; use of pharmaceutical intermediates, etc.

[Examples]

The method of the present invention will be described in more detail by way of examples, but the invention is not limited to the examples. In the following examples and comparative examples, unless otherwise specified, the composition is based on the area percentage value obtained by gas chromatography analysis.

<Example 1>

In a 500 mL autoclave (manufactured by SUS316L), dimethyl 1,4-naphthalene dicarboxylate (hereinafter referred to as "1,4-NDCM"; manufactured by Wako Pure Chemical Industries, Ltd.), 30 g, 5% Ru carbon powder A was charged. Type (5 mass% Ru/activated carbon catalyst; manufactured by NECHEMCAT Co., Ltd., water content: 52% by mass) 5.0 g, and isopropyl alcohol 30 g. The autoclave was subjected to nitrogen substitution twice at a pressure of 1 MPa at room temperature, and then hydrogen substitution was performed twice at a pressure of 1 MPa. After the pressure was reduced to normal pressure, the internal temperature was raised to 30 ° C, pressurized with hydrogen to 3 MPa, and stirred at the same temperature and at the same pressure for 2 hours (500 rpm at the time of stirring).

After completion of the reaction, the mixture was cooled to room temperature, hydrogen gas was released, and nitrogen substitution was carried out twice at a pressure of 1 MPa, and then the catalyst was filtered off to obtain a filtrate. Further, the catalyst to be used was washed three times with 20 g of acetone, and this washing liquid was recovered. The recovered washing liquid was added to the filtrate to prepare a mixed liquid. The solvent was distilled off from the obtained mixture to obtain 29.8 g of crude 1,4-tetrahydronaphthalene dicarboxylate (hereinafter referred to as "crude 1,4-TDCM"). The mixture was analyzed by gas chromatography, and the composition was: 1,4-NDCM: 2.8 mass%, 1,4-TDCM: 87.2 mass%, and dimethyl 5,8-tetrahydronaphthalene dicarboxylate (hereinafter referred to as "5,8-TDCM"): 3.6 mass%. The yield of 1,4-TDCM was 85.2%.

Further, 10 g of acetone and 30 g of decane were added to the crude 1,4-TDCM 10g, and completely dissolved by reflux, and then cooled to 0 ° C and recrystallized to separate the purified 1,4-TDCM.

Fig. 1 is a FT-IR (KBr method) chart showing crystals obtained by recrystallizing the product of Example 1. Fig. 2 is a chart showing the FT-IR (KBr method) of dimethyl 1,4-naphthalene dicarboxylate used as a raw material in Example 1. Fig. 3 shows the results of precision mass analysis of the crystal obtained by recrystallizing the product of Example 1 by GC-TOF/MS. Fig. 4 shows a ¹ H-NMR chart of the crystal obtained by recrystallizing the product of Example 1. Fig. 5 shows a ¹³ C-NMR chart of the crystal obtained by recrystallizing the product of Example 1. Figure 6 shows a dept135-NMR chart of the crystal obtained by recrystallizing the product of Example 1. Fig. 7 shows a ¹³ C-ig-NMR chart of the crystal obtained by recrystallizing the product of Example 1. Fig. 8 is a HMBC-NMR chart showing the crystal obtained by recrystallizing the product of Example 1. Fig. 9 is a HMQC-NMR chart showing the crystal obtained by recrystallizing the product of Example 1. Figure 10 shows an INADEQUATE-NMR chart of the crystal obtained by recrystallizing the product of Example 1. The identification of the product was carried out in accordance with the method described later.

<Example 2>

Into a 500 mL autoclave (manufactured by SUS316L), 1,4-NDCM (30 g), 5% Ru carbon powder type A (manufactured by N.E. CHEMCAT Co., Ltd., water content: 52% by mass), 5.0 g, and decane, 45 g, were placed. The autoclave was subjected to nitrogen substitution twice at a pressure of 1 MPa at room temperature, and then hydrogen substitution was performed twice at a pressure of 1 MPa. After the pressure was reduced to normal pressure, the internal temperature was raised to 40 ° C, pressurized with hydrogen to 3 MPa, and stirred at the same temperature and at the same pressure for 2 hours (500 rpm at the time of stirring).

After completion of the reaction, the mixture was cooled to room temperature, hydrogen gas was released, and nitrogen substitution was carried out twice at a pressure of 1 MPa, and then the catalyst was filtered off to obtain a filtrate. On the other hand, the used catalyst was washed 3 times with acetone 20 g and the washing liquid was recovered. The recovered washing liquid was added to the filtrate to prepare a mixed liquid. The solvent was distilled off from the obtained mixture to obtain 29.0 g of crude 1,4-TDCM. This was analyzed by gas chromatography, and as a result, the composition was 1,4-NDCM: 2.6 mass%, 1,4-TDCM: 85.9 mass%, and 5,8-TDCM: 3.5 mass%. The yield of 1,4-TDCM was 81.7%.

<Example 3>

Into a 500 mL autoclave (manufactured by SUS316L), 1,4-NDCM 30 g, 5% Rh carbon powder (5 mass% Rh/activated carbon catalyst; manufactured by NECHEMCAT Co., Ltd., water content: 52% by mass), 3.0 g, and isopropyl ester were placed. 30 g of alcohol. The autoclave was subjected to nitrogen substitution twice at a pressure of 1 MPa at room temperature, and then hydrogen substitution was performed twice at a pressure of 1 MPa. After the pressure is reduced to normal pressure, the internal temperature is raised to 70 ° C, pressurized with hydrogen to 3 MPa, and stirred at the same temperature and at the same pressure for 2 hours (rotation speed) 500 rpm).

After completion of the reaction, the mixture was cooled to room temperature, hydrogen gas was released, and after nitrogen substitution was performed twice at 1 MPa, the catalyst was filtered off to obtain a filtrate. On the other hand, the used catalyst was washed three times with 20 g of acetone and the washing liquid was recovered. The recovered washing liquid was added to the filtrate to prepare a mixed liquid. The solvent was distilled off from the obtained mixture to obtain 28.8 g of crude 1,4-TDCM. This was analyzed by gas chromatography, and the composition was 1,4-NDCM: 2.0% by mass, 1,4-TDCM: 73.1% by mass, and 5,8-TDCM: 13.7% by mass. The yield of 1,4-TDCM was 69.0%.

<Example 4>

Into a 500 mL autoclave (manufactured by SUS316L), 1,4-NDCM 30 g, 5% Pd carbon powder PE type (5 mass% Pd/activated carbon catalyst; manufactured by NECHEMCAT Co., Ltd., moisture content: 52% by mass) 4.0 g, Isopropyl alcohol 100g. The autoclave was subjected to two times of nitrogen substitution at a pressure of 1 MPa at room temperature, followed by two hydrogen substitutions at 1 MPa. After the pressure was reduced to normal pressure, the internal temperature was raised to 90 ° C, pressurized with hydrogen to 3 MPa, and stirred at the same temperature and at the same pressure for 2 hours (500 rpm at the time of stirring).

After completion of the reaction, the mixture was cooled to room temperature, hydrogen gas was released, and after nitrogen substitution was performed twice at 1 MPa, the catalyst was filtered off to obtain a filtrate. On the other hand, the used catalyst was washed three times with 20 g of acetone, and the washing liquid was recovered. The recovered washing liquid was added to the filtrate to prepare a mixed liquid. The solvent was removed from the obtained mixture to obtain crude 1,4-TDCM 29.9 g. This was analyzed by gas chromatography, and the composition was 1,4-NDCM: 0.3% by mass, 1,4-TDCM: 49.8% by mass, and 5,8-TDCM: 47.2% by mass. The yield of 1,4-TDCM was 48.8%.

<Product Identification>

The structure was identified by crystallizing the reaction product obtained in each of the examples by recrystallization. The analysis was carried out by FT-IR, NMR, and GC-TOF/MS, and the structure was identified based on the results.

[FT-IR measurement conditions]

Device: JASCO system, "FT-IR410"

Determination method: penetration method (KBr method)

Scanning range: 500~4000cm ^-1

Accumulated times: 64

Analytical ability: 4cm ^-1

Sample preparation: KBr was mixed and formed into a tablet.

[NMR measurement conditions]

Device: Bruker Avance II 600MHz-NMR

Detector: DCH CryoProbe

Mode: ¹ H, ¹³ C, ¹³ C-ig, dept135, HSQC, HMBC, INADEQUATE (measurement time 12 hours)

Sample preparation: 100 mg of crystals were dissolved in 500 μL of heavy chloroform.

[GC-TOF/MS measurement conditions]

Device: Agilent 7890A/WatersGCTpremier

Column: "DB-5MS UI" 30m × 0.25mmI.D. Membrane pressure 0.5μm

Heating conditions: 200 ° C (0 min) -10 ° C / min - 320 ° C (0 min)

Split ratio: 1:100

Injection temperature: 300 ° C

Injection volume: 1.0μL

Carrier gas: He, 1.0mL/min

Ionization method: 70eV, EI+ determination

Quality scan range: 33~800 (0.2sec)

DRE: ON

Trap Current: 200μA

Sourceo temperature: 300 ° C

Interface temperature: 320 ° C

Low Mass Cut OFF: 47Da

Internal Reference Material (Quality Correction): Heptacosa (m/z = 218.9856)

Sample preparation: The crystals were dissolved in a solution of chloroform, and the data obtained by diluting the peak intensity to an unsaturated concentration after the measurement was used for precision mass analysis.

The present application is based on a Japanese patent application filed on Sep. 28, 2012, to the Japanese Patent Office (Japanese Patent Application No. 2012-216369).

[Industry Utilization]

According to the present invention, a novel tetrahydronaphthalene derivative, 1,4-tetrahydronaphthalene dicarboxylate, can be industrially produced by selectively hydrogenating a 1,4-naphthalene dicarboxylate. Dialkyl 1,4-tetrahydronaphthalene dicarboxylate is considered to be useful as a polyester or a polycarbonate, a polyimide, a polyamine, a liquid crystal composition, a polymer modifier, a pharmaceutical intermediate or the like. Therefore, its industrial significance is great.

Claims (6)

a dialkyl 1,4-tetrahydronaphthalene dicarboxylate represented by the formula (1); (In the formula (1), R and R' each represent an alkyl group having 1 to 10 carbon atoms, and R and R' may be the same or different). A process for producing a dialkyl 1,4-tetrahydronaphthalene dicarboxylate comprising the steps of hydrogenating a 1,4-naphthalene dicarboxylate in a solvent in the presence of a noble metal catalyst. The method for producing a 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester according to the second aspect of the invention, wherein the noble metal catalyst is selected from the group consisting of a ruthenium catalyst, a rhodium catalyst, and a palladium catalyst. At least one of the groups. The method for producing a 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester according to claim 2, wherein the noble metal catalyst is selected from the group consisting of a ruthenium catalyst and a ruthenium catalyst. 1 species. A method for producing a 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester according to the second aspect of the invention, wherein the hydrogenation is carried out at a reaction temperature of from 0 to 100 °C. The method for producing a 1,4-tetrahydronaphthalene dicarboxylate dialkyl ester according to the second aspect of the invention, wherein the hydrogenation is carried out in the presence of a solvent, and the solvent is used in an amount relative to the 1,4-naphthalene The dialkyl dicarboxylate is in the range of 0.5 to 8 in terms of a mass ratio.