Method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl

Abstract

The present invention addresses the problem of providing a preparation method with which highly pure 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl can be obtained with good production efficiency. As a solution, the present invention provides a preparation method for 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by formula (3), said preparation method characterized by comprising a separation step in which a 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyl represented by formula (1) is used as a starting material to perform solid-liquid separation of a metal salt of a 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by formula (2) from a reaction mixture.

Description

[Technical field]

[0001] The present invention relates to a method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl. [Background technology]

[0002] In recent years, polyester resins and polyester carbonate resins, which use a dicarboxylic acid component having a binaphthalene skeleton as a polymerization component, have excellent optical properties such as a high refractive index and low birefringence, and are equipped with high heat resistance, and therefore are expected to be used as raw materials for optical components such as optical disks, transparent conductive substrates, and optical filters. Among them, resins produced using 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, which has a chemical structure represented by the following chemical formula, as a polymerization component have been attracting attention as being particularly excellent in optical properties (e.g., Patent Documents 1 to 3, etc.). [ka] Known methods for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the above chemical formula include a method of reacting 1,1'-binaphthalene-2,2'-diol with a halogenated acetate ester as shown in the following reaction formula, and a method of hydrolyzing the diester obtained by the above method (e.g., Patent Document 4, etc.). [ka] When the reaction solution is acidified after the hydrolysis reaction, if the reaction solution contains alcohol, the carboxylic acid of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl reacts with the alcohol to produce an ester, resulting in a problem of a decrease in the yield and purity of the target product. In order to avoid this problem, a method has been adopted in which the reaction solvent containing the alcohol derived from the ester is distilled off from the reaction system under reduced pressure after the hydrolysis reaction, and then the reaction solution is made acidic. However, the target product obtained by this method does not have sufficient purity and requires further purification. In addition, when the reaction solvent is distilled off from the reaction system under reduced pressure, it is necessary to add the reaction solvent to be reduced by distillation under reduced pressure later, or to use a large amount of it in advance from the start of the reaction. In addition, the solvent obtained by distillation under reduced pressure cannot be reused because it contains the alcohol derived from the ester, and must be discarded. On the other hand, from an industrial point of view, it was necessary to avoid the generation of such waste. Under these circumstances, there has been a demand for an efficient production method that can obtain the target product, 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, in high yield and high purity without having to remove the reaction solvent containing the ester-derived alcohol from the reaction system by vacuum distillation after the hydrolysis reaction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-002893 A [Patent Document 2] JP 2018-002894 A [Patent Document 3] JP 2018-002895 A [Patent Document 4] JP 2008-024650 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in light of the above-mentioned circumstances, and an object of the present invention is to provide a production method which has good production efficiency and is capable of obtaining high-purity 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl. [Means for solving the problem]

[0005] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that by providing a separation step for performing solid-liquid separation of a metal salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl from a reaction mixture, it is possible to obtain a target product with good production efficiency and with high purity, and have completed the present invention.

[0006] The present invention is as follows. 1. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the following formula (3), which comprises using 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyls represented by the following formula (1) as a starting material, and carrying out a separation step of solid-liquid separating a metal salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the following formula (2) from a reaction mixture. [ka] (In the formula, each R is independently an alkyl group having 1 to 8 carbon atoms.) [ka] (In the formula, each M independently represents sodium or potassium.) [ka] 2. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to 1, further comprising a decomposition step using the metal salt obtained in the separation step and an acid. 3. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to 1., comprising a reaction step of reacting 1,1'-binaphthalene-2,2'-diol with a halogenated acetate ester represented by the following formula (4) to obtain 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyl represented by the formula (1): [ka] (In the formula, X represents a halogen atom, and R represents an alkyl group having 1 to 8 carbon atoms.) Effect of the Invention

[0007] According to the present invention, the problem of the conventional hydrolysis reaction in which an ester-derived alcohol reacts with the target product to produce an ester, thereby reducing the purity of the target product, is solved, and high-purity 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl can be obtained. Moreover, according to the present invention, there is no need for a method of distilling off the reaction solvent containing the ester-derived alcohol from the reaction system under reduced pressure, which has been adopted to solve the above problems. This makes it possible to reduce the amount of reaction solvent used, and thus makes it possible to reduce the time, utility costs, material costs, and the like required for the entire production process to obtain a high-purity target product, as well as to suppress the generation of unnecessary waste, which is industrially advantageous. In other words, the production method of the present invention is extremely useful in the industrial production of resin raw materials and the like, since it has good production efficiency and can produce a target product with high purity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present invention will be described in detail below. The production method of the present invention is a method represented by the following reaction formula, and is characterized by having a separation step of performing solid-liquid separation of a metal salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the following formula (2) from a reaction mixture. Hereinafter, 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyls represented by the following formula (1) will be referred to as "diesters (1)", a metal salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the following formula (2) will be referred to as "metal salt (2)", and 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by the following formula (3) will be referred to as "target product A". [ka] (In the formula, each R independently represents an alkyl group having 1 to 8 carbon atoms, and each M independently represents sodium or potassium.)

[0009] <Reaction process for obtaining diester (1)> The "diesters (1)" in the present invention can be obtained by a method of reacting 1,1'-binaphthalene-2,2'-diol with a halogenated acetate ester represented by the following formula (4) (hereinafter referred to as "esters (4)"), as shown in the following reaction formula: [ka] (In the formula, each R is independently an alkyl group having 1 to 8 carbon atoms.)

[0010] (Esters (4)) "R" in the formula of ester (4) used in the synthesis of diester (1) is an alkyl group having 1 to 8 carbon atoms, and specific examples thereof include linear alkyl groups such as methyl, ethyl, and n-propyl groups, and branched alkyl groups in which the carbon bonded to the oxygen atom is a primary or secondary carbon, such as i-propyl and i-butyl groups. Among these, linear alkyl groups are preferred. Similarly, "X" in the formula is a halogen atom, and is preferably a chlorine atom, a bromine atom, or an iodine atom. In the synthesis of the diester (1), two or more kinds of esters (4) having different alkyl ester moieties may be used in combination, but it is preferable to use one kind of ester (4) in order to simplify purification. The amount of the ester (4) used is not particularly limited as long as it is equal to or greater than the theoretical value (2.0) as a molar ratio relative to 1,1'-binaphthalene-2,2'-diol, but is usually 2 moles or more, preferably 2.1 to 3.0 moles, and more preferably 2.2 to 2.8 moles.

[0011] (Reaction Solvent) The synthesis of the diester (1) does not require the use of a reaction solvent, but it is preferable to use one for reasons such as improved operability and reaction rate during industrial production. The reaction solvent is not particularly limited as long as it is not distilled from the reaction vessel at the reaction temperature and is inactive in the reaction. For example, chain or cyclic ketone solvents having 5 to 8 carbon atoms such as diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, 2-octanone, cyclopentanone, and cyclohexanone, and chain nitrile solvents having 2 to 6 carbon atoms such as acetonitrile and propanenitrile can be mentioned. These reaction solvents may be used alone, or two or more of them may be used in combination as appropriate to adjust the polarity. Among them, methyl isobutyl ketone and acetonitrile are preferable. The amount of the reaction solvent used is preferably in the range of 150 to 500 parts by weight, more preferably in the range of 200 to 300 parts by weight, based on 100 parts by weight of 1,1'-binaphthalene-2,2'-diol.

[0012] (base) The synthesis of the diester (1) is preferably carried out by forming a salt from 1,1'-binaphthalene-2,2'-diol with a base, and then reacting it with the ester (4). Such a base is not particularly limited, but for example, alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, etc., alkali metal hydrogen carbonates such as sodium hydrogen carbonate, potassium hydrogen carbonate, etc., alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, etc., as well as organic bases such as triethylamine and pyridine, etc. may be suitably used. These may be used alone or in combination of two or more. Among them, sodium carbonate and potassium carbonate are preferred. The amount of the base used is preferably 2.0 to 2.5 mol, more preferably 2.05 to 2.15 mol, per 1 mol of 1,1'-binaphthalene-2,2'-diol. (alkali metal iodides) In the synthesis of the diester (1), the reaction can be carried out in the presence of an alkali metal iodide. Specific examples of the alkali metal iodide include potassium iodide, sodium iodide, cesium iodide, and lithium iodide. These may be used alone or in combination of two or more. The amount of the alkali metal iodide used is preferably in the range of 1 to 25 mol %, more preferably in the range of 2 to 15 mol %, further preferably in the range of 2.5 to 10 mol %, and particularly preferably in the range of 3 to 5 mol %, relative to 1 mol of 1,1'-binaphthalene-2,2'-diol.

[0013] (Reaction temperature, pressure) The reaction temperature is usually 50 to 150°C, preferably 70 to 130°C, more preferably 90 to 110°C. If the reaction temperature is high, the yield decreases due to hydrolysis of the diester (1) produced, and if the reaction temperature is low, the reaction rate decreases, which is undesirable. The reaction is usually carried out under normal pressure, but depending on the boiling point of the organic solvent used, the reaction may be carried out under increased or reduced pressure so that the reaction temperature falls within the above range. (End point of reaction) The end point of the reaction can be confirmed by liquid chromatography or gas chromatography analysis. The end point of the reaction is preferably the time when the unreacted 1,1'-binaphthalene-2,2'-diol disappears and the increase in the diester (1) is no longer observed. The reaction time varies depending on the reaction conditions such as the reaction temperature, but is usually completed within about 1 to 30 hours. After the reaction is completed, water is added to the reaction solution, the mixture is stirred, and the mixture is left to stand to separate the aqueous layer. This washing operation is carried out two or more times to remove inorganic salts in the reaction solution. The amount of water used in each washing operation is preferably in the range of 150 to 600 parts by weight, more preferably in the range of 200 to 400 parts by weight, relative to 100 parts by weight of the 1,1'-binaphthalene-2,2'-diol used, and the temperature is preferably in the range of 60 to 100°C, more preferably in the range of 70 to 90°C. As for the stirring, it is sufficient that the oil layer is in sufficient contact with the aqueous layer, and the required time varies depending on the apparatus, but usually about 30 minutes is sufficient.

[0014] <Method for synthesizing metal salt (2)> (Reaction Solvent) In the synthesis of the metal salt (2) in the present invention, for example, the solution obtained after the completion of the synthesis reaction of the diester (1) and the completion of the water washing operation can be used. When using purified diester (1), it is preferable to use a mixed solvent of an organic solvent and water as the reaction solvent. Specific examples of the organic solvent to be used include chain or cyclic ketone solvents having 5 to 8 carbon atoms, such as diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, 2-octanone, cyclopentanone, and cyclohexanone, and chain nitrile solvents having 2 to 6 carbon atoms, such as acetonitrile and propanenitrile. The amount of the organic solvent to be used is preferably 100 to 600 parts by weight, more preferably 130 to 400 parts by weight, relative to 100 parts by weight of the diester (1). The amount of water to be used is preferably 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, relative to 100 parts by weight of the diester (1).

[0015] (base) A base is used to convert the diester (1) into a metal salt (2). Specific examples of the base used include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and the use of these bases makes it possible to obtain an alkali metal salt as the metal salt (2). The base used may be used as a solid or in the form of an aqueous solution. When the base is used as an aqueous solution, the concentration is preferably 10 to 60% by weight, more preferably 20 to 50% by weight. The amount of the base used is preferably 2.0 to 6.0 mol, more preferably 2.5 to 4.0 mol, per mol of the diester (1). (Reaction temperature) The reaction temperature is usually in the range of 30 to 100° C., preferably 50 to 90° C., more preferably 60 to 80° C., and it is preferable to add or dropwise add the above-mentioned base or an aqueous solution thereof while maintaining this temperature. The reaction usually completes in about 1 to 10 hours.

[0016] <Metal salt (2) separation process> The production method of the present invention is characterized by having a separation step of performing solid-liquid separation of the metal salt (2) from the reaction mixture. After the reaction to obtain metal salt (2) is completed, the reaction liquid is preferably cooled. The cooling rate is preferably 5 to 15° C. per hour, and more preferably 7 to 12° C. The final cooling temperature is preferably 20 to 60° C., and more preferably 25 to 35° C. After cooling the reaction liquid, the precipitated metal salt (2) can be filtered to obtain metal salt (2). It is preferable to remove as much of the mother liquor from the obtained metal salt (2) as possible. For this purpose, the obtained metal salt (2) may be washed with a solvent. When washing is performed, a mixed solvent of water and the organic solvent used in the synthesis of the metal salt (2) may be used, or water and an organic solvent may be used separately, for example, washing is first performed with water and then with an organic solvent. The amount of this mixed solvent used is preferably in the range of 10 to 200 parts by weight, more preferably 40 to 90 parts by weight, per 100 parts by weight of the diester (1).

[0017] <Decomposition process to obtain target A> The target product A in the present invention can be obtained by a decomposition step using a metal salt (2) and an acid. Specific examples of the acid used in this decomposition step include inorganic acids such as hydrogen chloride, hydrogen bromide, and sulfuric acid, and organic acids such as p-toluenesulfonic acid, methanesulfonic acid, and trifluoromethanesulfonic acid. The amount of these acids used is preferably 2.2 to 4.0 mol, more preferably 2.5 to 3.0 mol, per mol of the diester (1). When concentrated hydrochloric acid is used as the acid, the amount used is preferably 2.2 to 4.0 mol, more preferably 2.5 to 3.0 mol, calculated as hydrogen chloride, per 1 mol of the diester (1). Specific examples of the reaction solvent in the decomposition step include linear or cyclic ketone solvents having 5 to 8 carbon atoms, such as diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, 2-octanone, cyclopentanone, cyclohexanone, etc. The amount of the reaction solvent used is preferably 250 to 1050 parts by weight, more preferably 350 to 900 parts by weight, based on 100 parts by weight of the diester (1). In addition to the above reaction solvent, water can be used in combination as necessary to prevent salt precipitation.

[0018] <Removal process of object A> After the decomposition step, the reaction solution is allowed to stand, the aqueous layer is removed, and the dissolved target substance can be extracted from the resulting oil layer by a known method. For example, if necessary, water is added to the oil layer and the mixture is stirred, and then a water washing operation for separating the aqueous layer is performed several times, and the oil layer is crystallized and filtered to obtain the target substance. During crystallization, the amount of solvent and the amount of water can be adjusted by a distillation operation or the like, if necessary, to improve the yield, etc. EXAMPLES

[0019] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The analysis method is as follows. <Analysis method> 1. Confirmation of the target substance concentration in the reaction solution, reaction yield, and reaction end point After measurement under the conditions below, the purity (%) of the target compound A obtained in the examples and comparative examples was calculated using the liquid chromatography calibration curve of the target compound. Measurement equipment: High-performance liquid chromatography analyzer (manufactured by Shimadzu Corporation) Pump: LC-20AD Column oven: CTO-20A Detector: SPD-20A Column: HALO-C18 Oven temperature: 50℃ Flow rate: 0.7ml / min Mobile phase: (A) acetonitrile, (B) 0.1 vol% phosphoric acid water Gradient conditions: (A) Volume % (time from start of analysis) 30%(0min)→100%(12min)→100%(15min) Detection wavelength: 280nm

[0020] <Example 1> Manufacturing Method of the Present Invention 1 1,1'-binaphthalene-2,2'-diol (1213g), acetonitrile (3638g), potassium carbonate (1346g), and potassium iodide (121g) were charged into a four-neck flask, heated to 70°C, and stirred at the same temperature for 1 hour. After preparing a mixed solution of 1460g ethyl chloroacetate and 13g N-methylpyrrolidone, this mixed solution was added dropwise while keeping the temperature of the reaction solution at 70-80°C. After stirring for 6 hours, 3032g of water was added, heated to 70°C, and then allowed to stand to remove the water layer. Next, 3392g of 35% potassium hydroxide aqueous solution was added dropwise to the obtained oil layer while keeping the reaction solution temperature at 70-80°C. After 2 hours, the reaction solution was gradually cooled and filtered at 25°C (corresponding to the separation step of the present invention). The obtained crystals were washed with water (606 g) and then with acetonitrile (606 g) to obtain 2180 g of potassium salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl. The mother liquor was removed during filtration using centrifugal force (small centrifuge H-122, manufactured by Kokusan Co., Ltd.). Using 2051 g of the obtained potassium salt (undried), 3430 g of water and 9702 g of methyl isobutyl ketone were charged into a four-neck flask and heated to 80 ° C. to dissolve. 1207 g of concentrated hydrochloric acid was added dropwise while maintaining the temperature at 80-85 ° C., and stirred at the same temperature for 30 minutes. After standing, the aqueous layer was removed, and water was added to the obtained oil layer and stirred, and the aqueous layer was separated and removed. This water washing operation was repeated several times until the pH of the aqueous layer reached 4. Then, under normal pressure, water and 4713 g of methyl isobutyl ketone were distilled from the obtained oil layer by distillation. During the distillation, seed crystals obtained by a conventionally known manufacturing method were added at 95 ° C., and crystal precipitation was confirmed. Thereafter, the solution from which the crystals had precipitated was cooled to 25°C at a cooling rate of 10°C per hour, filtered, and then dried under reduced pressure to obtain 1,392 g of the crystalline form of target product A (yield: 86.8%, purity: 99.9%, monoethyl ester: 0.05%).

[0021] <Example 2> Manufacturing method 2 of the present invention 35g of 1,1'-binaphthalene-2,2'-diol, 52.5g of methyl isobutyl ketone, 35.5g of potassium carbonate, and 0.7g of potassium iodide were charged into a four-neck flask, heated to 100°C, and stirred at the same temperature for 2 hours. After preparing a mixed solution of 33.0g of ethyl chloroacetate and 0.3g of N-methylpyrrolidone, this mixed solution was added dropwise while maintaining the temperature of the reaction solution at 90-100°C. After stirring for 10 hours, 140g of water was added and the temperature was raised to 80°C, and then the mixture was left to stand and the water layer was removed. Next, 105.0g of methyl isobutyl ketone was added to the obtained oil layer, and 30.6g of 48% aqueous sodium hydroxide solution was added dropwise while maintaining the reaction solution temperature at 80-85°C. After 2 hours, the reaction solution was gradually cooled and filtered at 25°C (corresponding to the separation step of the present invention). The obtained crystals were confirmed to have low solubility in water (saturation concentration when dissolved in water at 30°C: 3.8% by weight). The crystals were washed with water (18 g) and then with methyl isobutyl ketone (18 g), obtaining 109.0 g of sodium salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl. Centrifugal force (small centrifuge H-122, manufactured by Kokusan Co., Ltd.) was used to remove the mother liquor during filtration. Using 63.5 g of the obtained sodium salt (undried), 244.7 g of methyl isobutyl ketone and 10.2 g of water were charged into a four-neck flask and heated to 80 ° C. to dissolve. 22.2 g of concentrated hydrochloric acid was added dropwise while maintaining the temperature at 80-85 ° C., and stirred at the same temperature for 30 minutes. After standing, the aqueous layer was removed, and water was added to the obtained oil layer and stirred, and the aqueous layer was separated and removed. This water washing operation was repeated several times until the pH of the aqueous layer became 4. Then, under normal pressure, water and 197.2 g of methyl isobutyl ketone were distilled from the obtained oil layer by distillation. During the distillation, seed crystals obtained by a conventionally known manufacturing method were added at 95 ° C., and crystal precipitation was confirmed. Thereafter, the solution from which the crystals had precipitated was cooled to 25°C at a cooling rate of 10°C per hour, filtered, and then dried under reduced pressure to obtain 25.2 g of the crystalline form of target product A (yield: 87.8%, purity: 99.9%, monoethyl ester: 0.05%).

[0022] <Comparative Example 1> -Production methods different from the production method of the present invention 35g of 1,1'-binaphthalene-2,2'-diol, 52.5g of methyl isobutyl ketone, 35.5g of potassium carbonate, and 0.7g of potassium iodide were charged into a four-neck flask, heated to 100°C, and stirred at the same temperature for 2 hours. After preparing a mixed solution of 33.0g of ethyl chloroacetate and 0.3g of N-methylpyrrolidone, this mixed solution was added dropwise while maintaining the temperature of the reaction solution at 90-100°C. After stirring for 10 hours, 140g of water was added and the temperature was raised to 80°C, and the water layer was removed. Next, 105.0g of methyl isobutyl ketone was added, and 30.6g of 48% aqueous sodium hydroxide solution was added dropwise while maintaining the reaction solution temperature at 80-85°C. After 2 hours, 185.5g of methyl isobutyl ketone and 105.0g of water were added to the reaction solution, and 38.2g of concentrated hydrochloric acid was added dropwise while maintaining the temperature at 80-85°C, and the mixture was stirred at the same temperature for 30 minutes. After standing, the aqueous layer was removed, and water was added to the obtained oil layer and stirred, and the aqueous layer was separated and removed. This was repeated several times until the pH of the aqueous layer reached 4. Then, under normal pressure, water and 231.6g of methyl isobutyl ketone were distilled from the obtained oil layer by distillation. At 95°C during the distillation, seed crystals obtained by a conventionally known manufacturing method were added to confirm the precipitation of crystals. After this, the solution in which the crystals were precipitated was cooled to 25°C at a cooling rate of 10°C per hour, filtered, and 51.5g of the crystals of the target product A was obtained (purity: 98.3%, monoethyl ester: 1.6%). (Crystallization of target product A) 30.0g of the obtained crystals of target A, 183.9g of methyl isobutyl ketone, and 9.8g of water were charged into a four-neck flask, and the temperature was raised to 85°C to dissolve. Then, 119.6g of water and methyl isobutyl ketone were distilled under normal pressure. During the distillation, at 95°C, seed crystals obtained by a conventionally known manufacturing method were added to confirm the precipitation of crystals. After this, the crystallization solution was cooled to 25°C at a cooling rate of 10°C per hour, filtered, and then dried under reduced pressure to obtain 24.8g of crystals of target A (yield: 86.4%, purity: 99.2%, monoethyl ester: 0.7%).

[0023] <Comparative Example 2> 38g of 1,1'-binaphthalene-2,2'-diol, 57g of methyl isobutyl ketone, 38.5g of potassium carbonate, and 0.76g of potassium iodide were charged into a four-neck flask, heated to 100°C, and stirred at the same temperature for 2 hours. After preparing a mixed solution of 35.8g of ethyl chloroacetate and 0.3g of N-methylpyrrolidone, this mixed solution was added dropwise while maintaining the temperature of the reaction solution at 90-100°C. After stirring for 10 hours, 152g of water was added, heated to 80°C, and then allowed to stand and the water layer was removed. 114g of methyl isobutyl ketone was added to the obtained oil layer, and 33.2g of 48% aqueous sodium hydroxide solution was added dropwise while maintaining the temperature of the reaction solution at 80-85°C. After stirring for 2 hours, 152 g of methyl isobutyl ketone was added, and 152 g of methyl isobutyl ketone, ethanol, and water were distilled out under normal pressure. 114 g of water and 201.4 g of methyl isobutyl were added, and 41.5 g of concentrated hydrochloric acid was added dropwise while maintaining the temperature at 80 to 85 ° C., and the mixture was stirred at the same temperature for 30 minutes. After standing, the aqueous layer was removed, and water was added to the obtained oil layer, stirred, and the aqueous layer was separated and removed. This was repeated several times until the pH of the aqueous layer reached 4. Then, under normal pressure, 244.1 g of water and methyl isobutyl ketone were distilled out from the obtained oil layer by distillation. At 95 ° C. during the distillation, seed crystals obtained by a conventionally known manufacturing method were added to confirm the precipitation of crystals. The mixture was cooled to 25 ° C. at a cooling rate of 10 ° C. per hour, and filtered to obtain 52.9 g of crystals (undried) of the target product A (purity: 99.7%, monoethyl ester: 0.20%). (Crystallization of target product A) 31.2 g of the obtained crystals of target A, 197.2 g of methyl isobutyl ketone, and 10.3 g of water were charged into a four-neck flask, and the temperature was raised to 85 ° C. to dissolve. Then, 124.9 g of water and methyl isobutyl ketone were distilled out by distillation under normal pressure. During the distillation, seed crystals obtained by a conventionally known manufacturing method were added at 95 ° C. to confirm the precipitation of crystals. Thereafter, the crystallized liquid was cooled to 25 ° C. at a cooling rate of 10 ° C. per hour, filtered, and then dried under reduced pressure to obtain 27.3 g of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl (yield: 86.7%, purity: 99.9%, monoethyl ester: 0.08%).

[0024] As shown in the above examples, in the production method of the present invention (Examples 1 and 2) in which metal salt (2) is separated from the reaction mixture by solid-liquid separation, the production of monoethyl esters is suppressed, and it has been confirmed that the purity of target product A is 99.9%, and the monoethyl ester contamination is 0.05%, making it possible to obtain crystals of extremely high purity. On the other hand, in the production method (Comparative Example 1) in which the metal salt (2) is not separated from the reaction mixture by solid-liquid separation, simply precipitating and filtering the crystals of the target product A only yields crystals of the target product A with a purity of 98.3% and containing 1.6% by weight of monoester, making it clear that a crystallization step is essential. Moreover, even when purification by crystallization and filtration was performed, only crystals of the target product A with a purity of 99.2% and containing only 0.7% of monoethyl ester were obtained. Furthermore, even in the production method (Comparative Example 2) in which the reaction solvent containing the ester-derived alcohol is distilled off from the reaction system under reduced pressure after the hydrolysis reaction and then the reaction solution is made acidic, it became clear that simply filtering the crystals of target product A would result in 0.2 wt% of the monoester being mixed in, and that a crystallization step in which the obtained crystals are dissolved in an organic solvent is essential. It has been revealed that the production method of the present invention is an excellent production method that does not require a method of distilling off the reaction solvent containing the alcohol derived from the ester from the reaction system under reduced pressure, and does not require a crystallization step of dissolving the obtained crystals in an organic solvent, and can obtain the target product with extremely high purity while maintaining a high yield. Moreover, according to the present invention, as shown in Example 2, it is possible to reduce the amount of solvent used, and it is possible to reduce the time, energy costs, material costs, etc. required for the entire production, and it is also possible to suppress the generation of unnecessary waste, so it has been confirmed that this is a very advantageous production method for the industrial production of resin raw materials, etc.

Claims

1. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by formula (3) below, comprising the steps of: starting with 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyl represented by formula (1) below, obtaining a metal salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl represented by formula (2) below using sodium hydroxide and / or potassium hydroxide; and subjecting the metal salt to solid-liquid separation from a reaction mixture. 【Chemistry 1】 (In the formula, each R is independently an alkyl group having 1 to 8 carbon atoms.) 【Chemistry 2】 (In the formula, each M independently represents sodium or potassium.) 【Chemistry 3】

2. 2. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, further comprising a decomposition step using the metal salt obtained in the separation step and an acid.

3. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, comprising a reaction step of reacting 1,1'-binaphthalene-2,2'-diol with a halogenated acetate ester represented by the following formula (4) to obtain a 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyl represented by the formula (1): 【Chemistry 4】 (In the formula, X represents a halogen atom, and R represents an alkyl group having 1 to 8 carbon atoms.)

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