Method for producing binaphthyl carboxylic acids

Abstract

The problem of the present invention is to provide a novel method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl suitable as a resin raw material with excellent optical properties. As a solution, a method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl is provided, characterized in that it comprises a step (1), wherein the step (1) sets the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more of the chain aliphatic ketones having 5 to 8 carbon atoms to a range of less than 2.0 wt % and more than 0.01 wt % and performs crystallization.

Description

Technical Field

[0001] The present invention relates to a method for producing binaphthyl carboxylic acids and, more particularly, to a method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl using a crystallization solvent containing a specific amount of water and composed of a chain aliphatic ketone having 5 to 8 carbon atoms. Background Art

[0002] In recent years, polyester resins or polyester carbonate resins using dicarboxylic acid components having a binaphthyl skeleton as polymer components have been highly anticipated as raw materials for optical components such as optical disks, transparent conductive substrates, and optical filters due to their excellent optical properties such as high refractive index and low birefringence, as well as high heat resistance. Among them, resins produced using 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl (hereinafter referred to as "compound A") having a chemical structure represented by the following chemical formula as a polymer component have attracted particular attention due to their excellent optical properties (e.g., Patent Documents 1 to 4, etc.).

[0003] [Chemical formula 1]

[0004]

[0005] As a method for producing the compound A represented by the above formula, as shown in the following reaction formula, a method is known in which 1,1'-binaphthyl-2,2'-diol is reacted with a haloacetic acid ester such as ethyl chloroacetate, and the resulting diester is hydrolyzed (for example, Patent Document 5, etc.). However, the compound A obtained by this reaction is often used by directly converting the crude product into an acid chloride by thionyl chloride or oxalyl chloride without purification, and therefore there has been no research or report on a purification method.

[0006] [Chemical formula 2]

[0007]

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2001-072872

[0010] Patent Document 2: Japanese Patent Application Publication No. 2018-002893

[0011] Patent Document 3: Japanese Patent Application Publication No. 2018-002894

[0012] Patent Document 4: Japanese Patent Application Publication No. 2018-002895

[0013] Patent Document 5: Japanese Patent Application Publication No. 2008-024650 Summary of the invention

[0014] The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a novel method for producing a compound A suitable as a raw material for a resin having excellent optical properties.

[0015] The present inventors have conducted intensive studies to solve the above problems and have found that the purification yield of high-purity Compound A can be improved by setting the water content in the crystallization solution to a specific range when performing crystallization using a specific solvent, thereby completing the present invention.

[0016] The present invention is as follows.

[0017] 1. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, comprising step (1) of setting the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more selected from linear aliphatic ketones having 5 to 8 carbon atoms to a range of 2.0 wt% to 0.01 wt% and performing crystallization.

[0018] 2. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, comprising the following steps (1) and (2):

[0019] Step (1): adjusting the water content in a solution containing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and one or more selected from linear aliphatic ketones having 5 to 8 carbon atoms to a range of 2.0 wt% or less and 0.01 wt% or more;

[0020] Step (2): Crystallizing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl from the solution of step (1).

[0021] 3. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to 1. or 2., characterized in that the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl in the above step (1) is a substance obtained by reacting 1,1'-binaphthyl-2,2'-diol with a haloacetic acid or a haloacetic acid ester.

[0022] According to the present invention, a highly pure compound A can be obtained at a much higher yield than in conventional production methods. In particular, since the purification yield of compound A can be improved, the present invention is excellent as an industrial production method.

[0023] That is, provision of the production method of the present invention is very useful for industrial applications of resin raw materials and the like. DETAILED DESCRIPTION

[0024] Hereinafter, the present invention will be described in detail.

[0025] The compound A of the present invention is a compound represented by the following chemical formula.

[0026] [Chemical formula 3]

[0027]

[0028] <About the synthesis method>

[0029] There are no particular limitations on the method for synthesizing the compound A of the present invention. Examples thereof include a synthesis method (a) in which a known 1,1'-binaphthyl-2,2'-diol is used as a starting material and reacted with a haloacetic acid such as chloroacetic acid, or a synthesis method (b) in which an etherification reaction is performed with a haloacetic acid ester such as ethyl chloroacetate to obtain a diester, followed by hydrolysis of the diester.

[0030] [Chemical formula 4]

[0031]

[0032] In the above synthesis method (a), since the reaction is carried out in the presence of a base such as an alkali metal carbonate such as lithium carbonate, sodium carbonate, potassium carbonate or an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, the target compound A can be obtained as an alkali metal salt.

[0033] In the above synthesis method (b), an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide or potassium hydroxide is used in the hydrolysis reaction to hydrolyze the diester. Therefore, the target compound A can be obtained as an alkali metal salt.

[0034] That is, in either of the above-mentioned synthesis methods (a) and (b), the obtained alkali metal salt is converted into compound A using an acid, but a water washing treatment is required to remove the inorganic substances generated at this time. The present inventors have newly found that if the water used for the water washing treatment is brought into the crystallization step of compound A to be performed next, the purification yield of compound A obtained in the crystallization step is greatly reduced, and have completed the present invention.

[0035] <Regarding steps (1) and (2)>

[0036] The production method of the present invention is characterized in that crystallization is performed using one or more crystallization solvents selected from linear aliphatic ketones having 5 to 8 carbon atoms.

[0037] Here, examples of the chain aliphatic ketone having 5 to 8 carbon atoms that can be used include diethyl ketone (carbon number 5), methyl isobutyl ketone (carbon number 6), methyl amyl ketone (carbon number 7), methyl hexyl ketone (carbon number 8), etc. Among them, methyl isobutyl ketone, methyl amyl ketone, and methyl hexyl ketone having low water solubility are preferred.

[0038] The crystallization solvent in the present invention may be used in combination with an organic solvent other than the linear aliphatic ketone having 5 to 8 carbon atoms unless the effects of the present invention are impaired, but is preferably composed only of the linear aliphatic ketone having 5 to 8 carbon atoms.

[0039] As for the compound A used in the step (1) of the present invention, examples include: crude crystals obtained by treating a reaction solution containing compound A, crystals obtained by recrystallizing the crude crystals, and residual liquid after distilling off the solvent from a solution containing compound A. It may also be amorphous. Compound A itself has two mirror image isomers, but as the compound A used in the crystallization step of the present invention, a racemic body is preferred, and the obtained crystals are also preferably a racemic body.

[0040] In step (1) of the production method of the present invention, it is important to adjust the water content in the crystallization solution to a range of 2.0 wt% or less and 0.01 wt% or more. The upper limit is preferably 1.7 wt% or less, more preferably 1.0 wt% or less. In addition, the lower limit is preferably 0.03 wt% or more, more preferably 0.05 wt% or more.

[0041] In addition, the water content in the present invention refers to the water content measured by the Karl Fischer method.

[0042] The amount of the linear aliphatic ketone having 5 to 8 carbon atoms used in step (1) is preferably 250 to 1000 parts by weight, more preferably 300 to 800 parts by weight, and further preferably 400 to 600 parts by weight, based on 100 parts by weight of compound A. When the temperature is raised to dissolve all the crystals, it may be done under normal pressure or under pressure, and when the amount is 450 parts by weight or less, it is preferably done under pressure.

[0043] It is sufficient to adjust the water content in the solution obtained by dissolving compound A in a linear aliphatic ketone having 5 to 8 carbon atoms to a range of 2.0 wt % or less and 0.01 wt % or more, and then cool and crystallize. For example, a method in which the water content in the residual solution is adjusted to a range of 2.0 wt % or less and 0.01 wt % or more while distilling the linear aliphatic ketone from the solution by distillation, and then cooling to precipitate crystals is relatively simple.

[0044] In step (2) of the present invention, the temperature for crystallization is preferably 90 to 120° C., more preferably 95 to 105° C. The time for solvent distillation is preferably 2 to 15 hours, more preferably 4 to 10 hours, and even more preferably 6 to 8 hours.

[0045] As the cooling rate when crystallizing by cooling and after crystallization, preferably 5 to 15°C per hour, more preferably 7 to 12°C. In addition, when crystallizing, seed crystals may not be used, but seed crystals are preferably used, and crystals obtained by a known manufacturing method or crystals obtained by precipitation without seed crystals are used as seed crystals. As the final cooling temperature, preferably 20 to 60°C, more preferably 25 to 35°C. After cooling to the above temperature, the precipitated crystals are separated by filtering.

[0046] <About the drying process>

[0047] The solvent used in the crystallization can be removed by drying the crystals obtained by crystallization. When drying the crystals obtained by crystallization, it is possible to dry them under normal pressure or reduced pressure, but when it is industrially implemented, it is more efficient to implement it under reduced pressure, and it is also suitable from the perspective of being able to remove the solvent used in the crystallization. It is preferably implemented at 60 to 120° C. under reduced pressure, and more preferably at 70 to 110° C. under reduced pressure.

[0048] Example

[0049] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0050] 1. Analysis method of water content

[0051] Measuring instrument: Karl Fischer MKS-520 (manufactured by Kyoto Electronics Co., Ltd.)

[0052] The water content was measured by volumetric titration using coulometric titrant (AQUAMICRON) SS 3 mg as a titrant.

[0053] 2. About the purity analysis method

[0054] Measuring device: High performance liquid chromatography analyzer (manufactured by Shimadzu Corporation)

[0055] Pump: LC-20AD

[0056] Column oven: CTO-20A

[0057] Detector: SPD-20A

[0058] Column: HALO-C18

[0059] Incubator temperature: 50℃

[0060] Flow rate: 0.7ml / min

[0061] Mobile phase: (A) acetonitrile, (B) 0.1 vol% phosphoric acid aqueous solution

[0062] Gradient conditions: (A) Volume % (from the start of analysis)

[0063] 30%(0min)→100%(12min)→100%(15min)

[0064] Detection wavelength: 280nm

[0065] After measurement under the above conditions, the purity (%) of the target compound obtained in the following Examples and Comparative Examples was calculated using the liquid chromatography calibration curve of the target compound.

[0066] <Synthesis example 1>

[0067] Synthesis of 2,2'-Bis(carboxymethoxy)-1,1'-binaphthyl potassium salt

[0068] 1,1'-binaphthyl-2,2'-diol 1213g, acetonitrile 3638g, potassium carbonate 1346g, potassium iodide 121g were placed in a four-necked flask, heated to 70°C, and stirred at the same temperature for 1 hour. After preparing a mixed solution of ethyl chloroacetate 1460g and N-methylpyrrolidone 13g, the mixed solution was added dropwise while the temperature of the reaction solution was kept at 70-80°C. After stirring for 6 hours, 3032g of water was added and the temperature was raised to 70°C, and the water layer was removed. Next, 3392g of a 35% potassium hydroxide aqueous solution was added dropwise while the temperature of the reaction solution was kept at 70-80°C. After 2 hours, the reaction solution was gradually cooled and filtered at 25°C to obtain 2180g of crystals of potassium salt of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl.

[0069] <Example 1>

[0070] 50.0 g of crystals obtained by drying the potassium salt obtained in Synthesis Example 1, 100 g of water, and 265 g of methyl isobutyl ketone were placed in a four-necked flask and heated to 80°C to dissolve. 30.0 g of concentrated hydrochloric acid was added dropwise while maintaining 80-85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was removed, and water was added to the obtained oil layer several times and stirred, and the water layer was separated and removed by washing until the pH of the water layer became 4. Then, water and 147 g of methyl isobutyl ketone were distilled from the obtained oil layer by distillation at normal pressure. During the distillation, seed crystals obtained by a conventionally known manufacturing method were added at 95°C and the precipitation of crystals was confirmed. The water content in the residual solution after distillation was 0.1%. The residual solution was cooled to 30°C at a cooling rate of 10°C per hour, filtered, and then dried to obtain 38.3 g of crystals of compound A. The yield was 91.0% and the purity was 99.9%.

[0071] <Example 2>

[0072] 50.0 g of crystals obtained by drying the potassium salt obtained in Synthesis Example 1, 100 g of water, and 265 g of methyl isobutyl ketone were placed in a four-necked flask and heated to 80°C to dissolve them. 30.0 g of concentrated hydrochloric acid was added dropwise while maintaining 80-85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was removed, and water was added to the obtained oil layer several times, stirred, and the water layer was separated and removed until the pH of the water layer became 4. Then, water and 147 g of methyl isobutyl ketone were distilled from the obtained oil layer by distillation at normal pressure. During the distillation, seed crystals obtained by a conventionally known manufacturing method were added at 95°C and the precipitation of crystals was confirmed. After that, water was added in such a way that the water content in the residual solution reached 0.4%, and the residual solution was cooled to 30°C at a cooling rate of 10°C per hour, filtered, and then dried to obtain 38.2 g of crystals of compound A. The yield was 90.9% and the purity was 99.9%.

[0073] <Example 3>

[0074] The same operation as in Example 2 was performed except that the water content of the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 0.7%, thereby obtaining 38.2 g of crystals of Compound A. The yield was 90.9% and the purity was 99.9%.

[0075] <Example 4>

[0076] The same operation as in Example 2 was performed except that the water content of the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.0%, thereby obtaining 37.8 g of crystals of Compound A. The yield was 90.1% and the purity was 99.9%.

[0077] <Example 5>

[0078] The same operation as in Example 2 was performed except that the water content of the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.3%, thereby obtaining 36.8 g of crystals of Compound A. The yield was 87.7% and the purity was 99.9%.

[0079] <Example 6>

[0080] The same operation as in Example 2 was performed except that the water content of the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 1.7%, thereby obtaining 36.4 g of crystals of Compound A. The yield was 86.6% and the purity was 99.9%.

[0081] <Comparative Example 1>

[0082] The same operation as in Example 2 was performed except that the water content of the residual solution after distilling off water and methyl isobutyl ketone was adjusted to 2.1%, thereby obtaining 33.4 g of crystals of Compound A. The yield was 79.5% and the purity was 99.9%.

[0083] <Comparative Example 2>

[0084] The same operation was carried out except that the methyl isobutyl ketone used in Example 1 was changed to methyl ethyl ketone and the water content in the solution was adjusted to 0.1%, thereby obtaining 33.9 g of crystals of compound A. The yield was 80.7% and the purity was 99.9%.

[0085] <Comparative Example 3>

[0086] In Comparative Example 2, the same operation was performed except that the amount of distilled water and methyl ethyl ketone was changed to 210 g and the water content in the solution was changed to 3.2%, thereby obtaining 21.7 g of crystals of Compound A. The yield was 51.7% and the purity was 99.9%.

[0087] <Comparative Example 4>

[0088] The same operation was carried out except that methyl isobutyl ketone used in Example 1 was replaced with cyclohexanone and the water content in the solution was set to 0.1%, thereby obtaining 32.2 g of crystals of compound A. The yield was 76.7% and the purity was 99.9%.

[0089] <Comparative Example 5>

[0090] In the above Comparative Example 4, the same operation was carried out except that the water content in the solution was changed to 1.5%, thereby obtaining 20.5 g of crystals of Compound A. The yield was 48.8% and the purity was 99.9%.

[0091] <Comparative Example 6>

[0092] 50.0 g of crystals obtained by drying the potassium salt obtained in Synthesis Example 1, 100 g of water, and 265 g of methyl isobutyl ketone (MIBK) were placed in a four-necked flask and heated to 80°C to dissolve. 30.0 g of concentrated hydrochloric acid was added dropwise while maintaining 80-85°C, and stirred at the same temperature for 30 minutes. After standing, the water layer was removed, and water was added to the obtained oil layer several times, stirred, and the water layer was separated and removed. The water washing operation was performed until the pH of the water layer became 4. Without adjusting the water content in the oil layer, the oil layer was cooled to 30°C at a cooling rate of 10°C per hour and filtered, and then dried to obtain 24.9 g of crystals of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl. The yield was 59.2% and the purity was 99.9%. In addition, the water content in the above oil layer was 5.2%.

[0093] The test results of Examples 1 to 6 and Comparative Examples 1 to 6 are summarized in Table 1 below.

[0094] [Table 1]

[0095]

[0096] As shown in Table 1, it is clear that by using methyl isobutyl ketone and adjusting the water content in the solution to a range of 2.0 wt% or less and 0.01 wt% or more (Examples 1 to 6), the purification yield of compound A with a purity of 99.9% can reach 85% or more. It is also confirmed that the efficiency of obtaining high-purity compound A is significantly improved compared to the production method without adjusting the water content (Comparative Example 6).

[0097] Furthermore, it is also clear from the results of Comparative Example 1 that setting the water content in the solution to a range of 2.0 wt % or less and 0.01 wt % or more has a critical significance.

[0098] Furthermore, it was also confirmed from the results of Comparative Examples 2 to 5 that the excellent improvement effect of the purification yield of the high-purity compound A is an effect exerted by using a specific solvent.

[0099] The above results show that the effect obtained by the production method of the present invention using a linear aliphatic ketone having 5 to 8 carbon atoms and adjusting the water content in the solution to a range of 2.0 wt % or less and 0.01 wt % or more is a particularly significant effect of critical significance.

Claims

1. A method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, characterized in that: The method comprises the following steps (1) and (2), Step (1): adjusting the water content in the solution of 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl and methyl isobutyl ketone to a range of 0.7 wt % or less and 0.01 wt % or more; Step (2): 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl is crystallized from the solution of step (1) at a precipitation temperature of 90 to 120°C.

2. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The lower limit of the water content is set to 0.03% by weight or more.

3. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The lower limit of the water content is set to 0.05% by weight or more.

4. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The usage amount of the methyl isobutyl ketone is 250 to 1000 parts by weight relative to 100 parts by weight of the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl.

5. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The usage amount of the methyl isobutyl ketone is 300 to 800 parts by weight relative to 100 parts by weight of the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl.

6. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The usage amount of the methyl isobutyl ketone is 400 to 600 parts by weight relative to 100 parts by weight of the 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl.

7. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The crystal precipitation temperature in the step (2) is 95 to 105°C.

8. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The cooling rate during the crystallization and after the crystals are precipitated in the step (2) is 5 to 15° C. per hour.

9. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The cooling rate during the crystallization and after the crystals are precipitated in the step (2) is 7 to 12° C. per hour.

10. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The final cooling temperature of the crystallization is 20-60°C.

11. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The final cooling temperature of the crystallization is 25-35°C.

12. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: After the crystallization, the precipitated crystals are further separated by filtration.

13. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The crystals obtained by the crystallization are dried.

14. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The crystals obtained by the crystallization are dried at 60 to 120° C. under reduced pressure.

15. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The crystals obtained by the crystallization are dried at 70 to 110° C. under reduced pressure.

16. The method for producing 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl according to claim 1, characterized in that: The 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl in the above step (1) is a product obtained by reacting 1,1'-binaphthyl-2,2'-diol with a haloacetic acid or a haloacetic acid ester.

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