Method for producing 1-adamantanecarboxylic acid chloride

Abstract

There has been a demand for a method for producing high-purity 1-adamantanecarboxylic acid chloride that minimizes the production of chloro-1-adamantanecarboxylic acid chloride. [Solution] The method for producing 1-adamantanecarboxylic acid chloride according to the present disclosure includes a reaction step of reacting adamantanecarboxylic acid with a chlorinating agent in the presence of a Lewis base, and a distillation step of purifying the resulting reaction solution containing 1-adamantanecarboxylic acid chloride by distillation, and is characterized in that at least one chlorine cation or chlorine radical scavenger selected from active methylene compounds, polycyclic aromatic hydrocarbons, polymerization inhibitors, and epoxy compounds is added to the reaction solution before the distillation step.

Description

[Technical Field]

[0001] The present invention relates to a method for producing 1-adamantanecarboxylic acid chloride.

[0002] As used herein, the term "high purity" means that the concentration of the by-product chloro-1-adamantanecarboxylic acid chloride is 0.01 to 0.05 GC% in the produced 1-adamantanecarboxylic acid chloride. [Background technology]

[0003] Due to its optical properties and heat resistance, the adamantane skeleton is used as a raw material for various highly functional industrial optical materials such as optical disk substrates, optical fibers, and lenses (Patent Document 1). Among these, 1-adamantanecarboxylic acid chloride, which contains a reactive functional group, a chlorocarbonyl group, is used as a useful compound for incorporating the adamantane skeleton into functional molecules. Even for highly functional materials, high purity and absence of by-products are desirable when used as raw materials for electronic information materials, etc. In particular, metal impurities must be controlled at the ppm level.

[0004] [ka]

[0005] Several methods for producing 1-adamantanecarboxylic acid chloride are known, but with the exception of reagents, few of them have enabled industrial production of high-purity 1-adamantanecarboxylic acid chloride (Patent Document 2, Patent Document 3). The only known industrially practicable method is the production method described in Patent Document 4. In this production method, 1-adamantanecarboxylic acid is reacted with a chlorinating agent such as thionyl chloride. In this process, a Lewis base is present in the system to suppress the decarbonylation reaction caused by trace amounts of metal impurities derived from the raw material adamantanecarboxylic acid contained in the system. This prevents contamination with chloroadamantane produced in the decarbonylation reaction, making it possible to produce highly pure 1-adamantanecarboxylic acid chloride.

[0006] However, the inventors' investigations revealed that even if the Lewis base is added during the reaction, heating during the subsequent distillation purification stage results in the generation of a small amount of chloro-1-adamantanecarboxylic acid chloride (ADOC-Cl, e.g., 1-chloro-3-adamantanecarboxylic acid chloride), a by-product in which chlorine is directly bonded to the adamantane ring. This by-product cannot be sufficiently suppressed by simply adding a Lewis base. While it is possible to separate the by-product chloro-1-adamantanecarboxylic acid chloride by distillation, the small boiling point difference between 1-adamantanecarboxylic acid chloride and chloro-1-adamantanecarboxylic acid chloride necessitates the use of a distillation column with many plates and a long distillation time. Furthermore, to suppress the by-production of chloro-1-adamantanecarboxylic acid chloride due to heating during distillation, distillation at low temperatures under highly reduced pressure is necessary. Such special purification conditions require significant equipment costs, making high-purity 1-adamantanecarboxylic acid chloride extremely expensive.

[0007] [ka]

[0008] The by-product chloro-1-adamantanecarboxylic acid chloride has the same carboxylic acid chloride moiety as 1-adamantanecarboxylic acid chloride, and as it is incorporated into the final product, affecting its quality, it requires particularly strict management compared to other by-products. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-171120 [Patent Document 2] Special Publication No. 59-514 [Patent Document 3] Special Publication No. 2016-509000 [Patent Document 4] Japanese Patent Application Publication No. 2019-001742 Summary of the Invention [Problem to be solved by the invention]

[0010] As mentioned above, the method described in Patent Document 4 makes it possible to suppress decarbonylation and produce high-purity 1-adamantanecarboxylic acid chloride, but it is difficult to suppress the generation of chloro-1-adamantanecarboxylic acid chloride, which is a by-product under heating conditions during distillation. In order to use 1-adamantanecarboxylic acid chloride as a raw material for electronic information materials, etc., it is necessary to suppress the incorporation of chloro-1-adamantanecarboxylic acid chloride as much as possible, and there has been a demand for a method for producing high-purity 1-adamantanecarboxylic acid chloride with as little chloro-1-adamantanecarboxylic acid chloride as possible. A challenge in conventional methods for producing 1-adamantanecarboxylic acid chloride was how to suppress the generation of chloro-1-adamantanecarboxylic acid chloride, a by-product produced under heating conditions during distillation. [Means for solving the problem]

[0011] The present inventors have conducted extensive research into the above-mentioned problems and have surprisingly found that by adding a certain type of chlorine cation or chlorine radical scavenger to the reaction solution before distillation purification, the increase in the amount of chloro-1-adamantanecarboxylic acid chloride produced as a by-product under heating conditions can be suppressed to 0.02 GC% or less. As a result, even when combined with the 0.02 to 0.03 GC% of chloro-1-adamantanecarboxylic acid chloride contained in the reaction solution before distillation, the total concentration of chloro-1-adamantanecarboxylic acid chloride can be suppressed to 0.01 to 0.05 GC%, thereby completing a method for producing high-purity 1-adamantanecarboxylic acid chloride. Specifically, the present invention has the following features.

[0012] (1) a reaction step of reacting an adamantanecarboxylic acid with a chlorinating agent in the presence of a Lewis base; a distillation step of purifying the obtained reaction liquid containing 1-adamantanecarboxylic acid chloride by distillation, a method for producing 1-adamantanecarboxylic acid chloride, comprising adding at least one chlorine cation or chlorine radical scavenger selected from the group consisting of active methylene compounds, polycyclic aromatic hydrocarbons, polymerization inhibitors, and epoxy compounds to the reaction solution before the distillation operation. (2) The method for producing 1-adamantanecarboxylic acid chloride according to (1), wherein the Lewis base is at least one selected from the group consisting of organic phosphorus compounds, organic amine compounds, and organic sulfur compounds. (3) The method for producing 1-adamantanecarboxylic acid chloride according to (1) or (2), wherein the active methylene compound is selected from the group consisting of malonic acid diesters, acetoacetic acid esters, malononitrile, cyanoacetic acid esters, and 1,3-cycloalkanedione. (4) The method for producing 1-adamantanecarboxylic acid chloride according to (1) or (2), wherein the polycyclic aromatic hydrocarbon is selected from acenes, fullerenes, pyrenes, perylenes, and derivatives thereof. (5) The method for producing 1-adamantanecarboxylic acid chloride according to (1) or (2), wherein the polymerization inhibitor is selected from the group consisting of 3,5-di-t-butyl-4-hydroxytoluene, 2,6-di-t-butylphenol, di-t-butyl-7-phenylquinone methide, and 2,2-diphenyl-1-picrylhydrazyl. (6) The method for producing 1-adamantanecarboxylic acid chloride according to (1) or (2), wherein the epoxy compound is selected from the group consisting of 1,2-epoxyoctadecane, 1,5-hexadiene diepoxide, and 1,7-octadiene diepoxide. [Effects of the Invention]

[0013] The method of the present invention can provide a method for producing 1-adamantanecarboxylic acid chloride that solves the above-mentioned problems, and can suppress the concentration of chloro-1-adamantanecarboxylic acid chloride to 0.01 to 0.05 GC% even under heating conditions during distillation. In addition, a distillation column with high separation capacity for removing chloro-1-adamantanecarboxylic acid chloride is not required, and distillation can be performed in a short time, so that high-purity 1-adamantanecarboxylic acid chloride with a chloro-1-adamantanecarboxylic acid chloride concentration suppressed to 0.01 to 0.05 GC% can be produced industrially at low cost. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a graph showing the generation behavior of chloro-1-adamantanecarboxylic acid chloride in the comparative examples and examples shown in Table 2. DETAILED DESCRIPTION OF THE INVENTION

[0015] The method of the present invention is a method for producing high-purity 1-adamantanecarboxylic acid chloride having a chloro-1-adamantanecarboxylic acid chloride concentration of 0.01 to 0.05 GC% by adding a chlorine cation or a chlorine radical scavenger to the reaction solution before distillation, thereby suppressing the production of chloro-1-adamantanecarboxylic acid chloride even under heating conditions. Note that the following description of the constituent elements will be given based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment and various modifications can be made without departing from the spirit of the present invention.

[0016] <Preparation of reaction solution containing 1-adamantanecarboxylic acid chloride> In the production of 1-adamantanecarboxylic acid chloride, for example, 1-adamantanecarboxylic acid is used as a starting material, and after adding a Lewis base to suppress the decarbonylation reaction, the material is reacted with a chlorinating agent. Chlorinating agents that can be used in the reaction step include thionyl chloride, oxalyl chloride, phosphorus pentachloride, and phosphoryl chloride, with thionyl chloride being preferred.

[0017] The amount of the chlorinating agent used is preferably 0.1 to 5.0 mol, more preferably 1.0 to 2.0 mol, per 1 mol of the starting material adamantanecarboxylic acid.

[0018] As used herein, the term "Lewis base" refers to a substance that donates an electron pair to form a chemical bond with another substance, but does not include nucleophiles that cause a nucleophilic substitution reaction on the carbonyl carbon, i.e., the acyl carbon, of adamantanecarboxylic acid chloride.

[0019] The Lewis base to be added can be selected from, for example, organic phosphorus compounds, organic amine compounds, and organic sulfur compounds. It is believed that these Lewis bases are effective in suppressing the decomposition of adamantanecarboxylic acid by trace impurities such as metal components. It is known that 1-chloroadamantane is produced as a by-product when 1-adamantanecarboxylic acid chloride is produced. This is thought to be due to the acid catalytic action of trace impurities. The Lewis base suppresses this acid catalytic action, thereby suppressing the by-production of 1-chloroadamantane, i.e., the decomposition of 1-adamantanecarboxylic acid chloride.

[0020] Specific examples include triphenylphosphine, triphenylphosphine oxide, triethylamine, and diphenyl sulfide, and these can be used alone or in combination of two or more. At least one of the Lewis bases used is preferably triphenylphosphine or triphenylphosphine oxide, and more preferably triphenylphosphine.

[0021] Trace impurities that cause the decomposition of adamantanecarboxylic acid chloride include metal components such as Na, K, Fe, Ni, Cr, Cu, Mn, Co, Ti, Zn, Pb, and Al. These metal components originate from the raw material adamantanecarboxylic acid. These metal components react with the chlorinating agent to form Lewis acids. If the material is heated during a distillation operation or other process while still containing this Lewis acid, the adamantanecarboxylic acid chloride produced in the reaction process will decompose. Therefore, it cannot be removed from the reaction vessel in this state (i.e., the distillation operation cannot be performed). Therefore, by adding a Lewis base before the distillation operation, it reacts with the Lewis acid derived from the raw material contained in the vessel (detoxifying it), making it possible to heat the vessel.

[0022] The amount of Lewis base used in the reaction step is preferably 0.1 to 10.0 parts by mass, and more preferably 1.0 to 6.0 parts by mass, per 100 parts by mass of adamantanecarboxylic acid.

[0023] The reaction temperature is preferably 0 to 80° C., more preferably 20 to 70° C. The reaction time is appropriately selected depending on conditions such as the reaction temperature, but is preferably 1 to 30 hours, more preferably 1 to 12 hours.

[0024] If necessary, a catalyst may be added to the reaction vessel to activate the chlorinating agent, such as a carboxylic acid amide such as N,N-dimethylformamide or N,N-dimethylacetamide, or an aromatic amine such as pyridine or quinoline, with N,N-dimethylformamide or pyridine being preferred.

[0025] The amount of the catalyst used is preferably 0.001 to 1.000 mol, and more preferably 0.010 to 0.500 mol, per 1 mol of adamantanecarboxylic acid.

[0026] The reaction mixture of 1-adamantanecarboxylic acid chloride prepared as above is then sent to a distillation step for purification.

[0027] In the present invention, the formation of chloro-1-adamantanecarboxylic acid chloride during the distillation step can be suppressed by adding the following chlorine cation or chlorine radical scavenger before the distillation step.

[0028] <Possible mechanism of ADOC disproportionation reaction during distillation process> The effect of the chlorine cation or chlorine radical scavenger used in the production method of the present invention in suppressing the generation of chloro-1-adamantanecarboxylic acid chloride is believed to manifest as follows: In other words, it is presumed that in the distillation step, 1-adamantanecarboxylic acid chloride generates a very small amount of chlorine cations or chlorine radicals through thermal decomposition, and these react with another 1-adamantanecarboxylic acid chloride molecule to produce chloro-1-adamantanecarboxylic acid chloride as a by-product. In the production method of the present invention, it is believed that the side reaction is suppressed by adding a scavenger to capture the generated chlorine cations or chlorine radicals.

[0029] <Type of chlorine cation or chlorine radical scavenger> Examples of chlorine cation or chlorine radical scavengers to be added to the reaction solution before the distillation step include active methylene compounds, polycyclic aromatic hydrocarbons, polymerization inhibitors, and epoxy compounds. All of these compounds function as scavengers to capture chlorine cations or chlorine radicals generated by thermal decomposition.

[0030] Examples of the active methylene compound include malonic acid diester, acetoacetic acid ester, malononitrile, cyanoacetic acid ester, 1,3-cyclohexanedione, etc. Malonic acid diester and 1,3-cyclohexanedione are more preferred.

[0031] Examples of polycyclic aromatic hydrocarbons include acenes, fullerene, pyrene, perylene, and derivatives thereof, etc. Acenes are preferred, and anthracene is more preferred.

[0032] Examples of the polymerization inhibitor include 3,5-di-t-butyl-4-hydroxytoluene, 2,6-di-t-butylphenol, di-t-butyl-7-phenylquinone methide, 2,2-diphenyl-1-picrylhydrazyl, etc. 3,5-di-t-butyl-4-hydroxytoluene is preferred.

[0033] Examples of epoxy compounds include 1,2-epoxyoctadecane, 1,5-hexadiene diepoxide, 1,7-octadiene diepoxide, etc. 1,2-epoxyoctadecane is preferred.

[0034] Of the above-mentioned scavengers, diethyl malonate, 1,3-cyclohexanedione, anthracene, 3,5-di-t-butyl-4-hydroxytoluene, and 1,2-epoxyoctadecane are more preferred.

[0035] <Timing of scavenger injection> The timing of adding the chlorine cation or chlorine radical scavenger is not particularly limited as long as it is before heating the reaction liquid in the distillation step, but it is preferably after the completion of the reaction step and before heating for distillation.

[0036] <Amount of chlorine cation or chlorine radical scavenger used> The amount of the chlorine cation or chlorine radical scavenger used is preferably 1 to 30 parts by mass per 100 parts by mass of adamantanecarboxylic acid. If it is less than 1 part by mass, the effect of suppressing the increase in ADOC-Cl is insufficient, and if it exceeds 30 parts by mass, separation in the distillation step becomes difficult, which is undesirable. It is more preferably 5 to 15 parts by mass.

[0037] <Distillation conditions (distillation temperature, distillation pressure)> In the production method of the present invention, the specific distillation temperature of the reaction solution is preferably in the range of 110 to 190°C. A distillation temperature below 110°C requires a significantly high degree of vacuum, which is undesirable as it requires a huge investment in equipment. Furthermore, a distillation temperature above 190°C is undesirable as it makes it impossible to suppress the increase in chloro-1-adamantanecarboxylic acid chloride even in the present invention. The distillation temperature affects the length of the distillation time, but in the production method of the present invention, the production of by-products is suppressed, so the increase in chloro-1-adamantanecarboxylic acid chloride remains unchanged. The distillation pressure is necessary to keep the boiling point of ADOC at 135°C or lower, so it is preferably 1 kPa or less, more preferably 0.2 kPa or less.

[0038] By using the production method of the present invention, the generation of chlorine cations or chlorine radicals is suppressed, and therefore high-purity 1-adamantanecarboxylic acid chloride having a concentration of the by-product chloro-1-adamantanecarboxylic acid chloride of 0.01 to 0.05 GC% can be obtained through a short distillation operation, and the method can be produced industrially at low cost.

[0039] <Distillation apparatus> Equipment handling acid chlorides must avoid using metals in wetted parts. Therefore, for example, glass-lined distillation columns and piping, and glass or ceramic packings must be used for distillation purification of 1-adamantanecarboxylic acid chloride. Furthermore, the difference in boiling points between the by-product chloro-1-adamantanecarboxylic acid chloride and 1-adamantanecarboxylic acid chloride is small. Therefore, to obtain high-purity 1-adamantanecarboxylic acid chloride without using the production method of the present invention, distillation purification is required using a large amount of packing in the distillation column and a distillation equipment with a large number of theoretical plates. Glass or ceramic packings require thickness for strength, and therefore are heavier than typical metal packings. Therefore, to prepare equipment with a large number of theoretical plates, the equipment structure must be particularly robust. This results in high capital investment costs.

[0040] The production method of the present invention can suppress the generation of chloro-1-adamantanecarboxylic acid chloride, a by-product during distillation, and therefore enables purification and separation in a short time using small equipment with a small number of theoretical plates. Although glass-lined distillation columns and piping are required, high-purity 1-adamantanecarboxylic acid chloride can be produced industrially at low cost without the need for expensive rectification equipment. [Example]

[0041] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0042] <Analysis by gas chromatography> Measurement conditions Equipment: Gas chromatograph GC-2014 (Shimadzu Corporation) Column: InertCap1 (inner diameter 0.25 mm ID x length 60 m, film thickness 0.40 μm, manufactured by GL Sciences) Detector: FID, INJ (vaporizer temperature): 250°C, DET (detector temperature): 300°C Column temperature: Maintain 70°C for 1 minute, then increase the temperature to 200°C at a rate of 10°C / min, maintain at 200°C for 5 minutes, then increase the temperature to 250°C at a rate of 10°C / min, maintain at 250°C for 6 minutes. Column flow rate: 1.37 mL / min (helium), split ratio: 13.9 Preparation of analytical sample: Dilute approximately 0.1 g of sample with 10 mL of dry methanol and react to obtain a solution of the ester form.

[0043] Analysis conditions Data processing device: PACSolutions (Shimadzu Corporation), Chromatopac C-R8A (Shimadzu Corporation) Analysis parameters: WIDTH=3, SLOPE=100, DRIFT=0, MIN.AREA=40, T.DBL=1000

[0044] The increase in the concentration of ADOC and the concentration of ADOC-Cl (GC%) was calculated using the area percentage method, excluding the peaks from the added chlorine cation or chlorine radical scavengers to avoid the influence of their peak size.

[0045] The concentration analysis of ADOC and ADOC-Cl was carried out according to the following procedure. (1) For the analysis results from 5 minutes onwards, calculate the area value of each peak in accordance with the above analysis parameters. (2) Specify the peaks originating from the additives and perform a process to exclude the area values ​​of those peaks from the calculation. The RTs of each additive are as follows: 1,3-Dimethoxybenzene: RT11.2 Anisole: RT7.5 1,2-Epoxyoctadecane: RT30.0 Diethyl malonate: RT9.5 Anthracene: RT22.0 Dibutylhydroxytoluene: RT16.5 Cyclohexanedione: RT11.9 (3) The area percentage of the peak at RT15.8 is the analytical value of ADOC. (4) The area % of the peak at RT 19.0 is the analytical value of ADOC-Cl.

[0046] <Preparation of 1-adamantanecarboxylic acid chloride reaction solution> A 1000 mL four-neck flask equipped with a stirrer, thermometer, condenser, and dropping funnel was prepared. The condenser was filled with water set at 10°C. 379.4 g (2.1 mol) of 1-adamantanecarboxylic acid and 38.1 g (0.14 mol) of triphenylphosphine oxide as a Lewis base were added at room temperature and heated in a mantle heater at 80°C. After the thermometer inserted into the powder reached 65°C, 294.0 g (2.5 mol) of thionyl chloride was added dropwise using a 200 mL dropping funnel over 3 hours. Two hours after the start of the addition, the flask was confirmed to be liquid, and stirring was commenced at 300 rpm. After the addition was complete, the liquid temperature was lowered to 75-80°C and aged overnight (20 hours). Thereafter, a capillary tube connected to an N2 balloon was placed in the flask, and excess thionyl chloride was distilled off by bubbling N2 at a liquid temperature of 70 to 80°C for 1 hour under reduced pressure (3 to 5 kPa). In this way, 453.8 g of 1-adamantanecarboxylic acid chloride reaction solution was obtained. The purity of 1-adamantanecarboxylic acid chloride in the obtained reaction solution was 99.40 to 99.45 GC%, and the amount of chloro-1-adamantanecarboxylic acid chloride before the distillation operation was 0.02 to 0.03 GC% by analysis using gas chromatography.

[0047] In order to confirm the phenomenon that the by-product chloro-1-adamantanecarboxylic acid chloride increases due to heating during the distillation operation, the following test was carried out in which the reaction mixture was heated as is instead of the distillation operation.

[0048] (Comparative Example 1) 8 g of the 1-adamantanecarboxylic acid chloride reaction solution prepared as described above was placed in a 30 mL test tube and subjected to a heating test at 135°C. As a result, the amount of chloro-1-adamantanecarboxylic acid chloride increased with each heating time, and the amount of chloro-1-adamantanecarboxylic acid chloride in the reaction solution after 24 hours was 0.28 GC%. In other words, it increased by 0.26 GC% from before heating.

[0049] (Comparative Example 2) To confirm the by-product suppression effect of increasing the amount of Lewis acid, 0.8 g (10 mass%) of triphenylphosphine oxide (TPPO) was further added to 30 mL of 8 g of the 1-adamantanecarboxylic acid chloride reaction solution used in Comparative Example 1, and a heating test was carried out at 135°C. As a result, the amount of chloro-1-adamantanecarboxylic acid chloride increased with each heating time, and the increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.12 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.15 GC%, and it cannot be said that the production of chloro-1-adamantanecarboxylic acid chloride in the obtained 1-adamantanecarboxylic acid chloride was suppressed.

[0050] (Comparative Example 3) To confirm the suppression effect of by-products due to the addition of a nucleophilic reagent, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of 1,3-dimethoxybenzene was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.07 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.09 GC%, and it cannot be said that chloro-1-adamantanecarboxylic acid chloride in the obtained 1-adamantanecarboxylic acid chloride was suppressed.

[0051] Comparative Example 4 To confirm the suppression effect of by-products due to the addition of a nucleophilic reagent, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of anisole was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.05 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.08 GC%, and it cannot be said that chloro-1-adamantanecarboxylic acid chloride in the obtained 1-adamantanecarboxylic acid chloride was suppressed.

[0052] Example 1 To confirm the by-product suppression effect of adding a chlorine cation or chlorine radical scavenger, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of 1,2-epoxyoctadecane was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.02 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.04 GC%, and 1-adamantanecarboxylic acid chloride was obtained in which the production of chloro-1-adamantanecarboxylic acid chloride was suppressed.

[0053] Example 2 To confirm the by-product suppression effect of adding a chlorine cation or chlorine radical scavenger, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of diethyl malonate was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.02 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.05 GC%, and 1-adamantanecarboxylic acid chloride was obtained in which the production of chloro-1-adamantanecarboxylic acid chloride was suppressed.

[0054] Example 3 To confirm the by-product suppression effect of adding a chlorine cation or chlorine radical scavenger, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of anthracene was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was 0.01 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was 0.03 GC%, and 1-adamantanecarboxylic acid chloride was obtained in which the production of chloro-1-adamantanecarboxylic acid chloride was suppressed.

[0055] Example 4 To confirm the effect of adding a chlorine cation or chlorine radical scavenger in suppressing by-products, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of 3,5-di-t-butyl-4-hydroxytoluene (BHT) was used instead of triphenylphosphine oxide. The increase in the amount of chloro-1-adamantanecarboxylic acid chloride after 24 hours was less than 0.01 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was less than 0.03 GC%, and 1-adamantanecarboxylic acid chloride was obtained in which the production of chloro-1-adamantanecarboxylic acid chloride was suppressed.

[0056] Example 5 To confirm the by-product suppression effect of adding a chlorine cation or chlorine radical scavenger, a heating test was carried out according to the method of Comparative Example 2, except that 0.8 g (10 mass%) of 1,3-cyclohexanedione was used instead of triphenylphosphine oxide. Even after 24 hours, the increase in the amount of chloro-1-adamantanecarboxylic acid chloride was less than 0.01 GC%. As a result, the content of chloro-1-adamantanecarboxylic acid chloride in the reaction solution was less than 0.04 GC%, and 1-adamantanecarboxylic acid chloride was obtained in which the production of chloro-1-adamantanecarboxylic acid chloride was suppressed.

[0057] In each test (Comparative Example and Example), the amount of ADOC-Cl (GC%) and the increase in ADOC-Cl (GC%) after heating the reaction solution for 24 hours are shown in Table 1 below, and the increase in ADOC-Cl per reaction time is shown in Table 2 and Figure 1.

[0058] [Table 1]

[0059] [Table 2]

[0060] In all of Examples 1 to 5, the increase in ADOC-Cl amount after 24 hours of heating was 0.00 to 0.02 GC%. This indicates that the method for producing 1-adamantanecarboxylic acid chloride of the present invention can adjust the concentration of the by-product chloro-1-adamantanecarboxylic acid chloride in the produced 1-adamantanecarboxylic acid chloride to 0.01 to 0.05 GC%. [Industrial Applicability]

[0061] The high-purity 1-adamantanecarboxylic acid chloride obtained by the present invention is useful for industrial products in fields where strict control of impurity levels is required, such as electronic information materials, and is particularly useful for applications where impurity control on the order of several hundred ppm is required.

Claims

1. a reaction step of reacting an adamantanecarboxylic acid with a chlorinating agent in the presence of a Lewis base; a distillation step of purifying the obtained reaction solution containing 1-adamantanecarboxylic acid chloride by distillation, a method for producing 1-adamantanecarboxylic acid chloride, comprising adding at least one chlorine cation or chlorine radical scavenger selected from the group consisting of active methylene compounds, polycyclic aromatic hydrocarbons, polymerization inhibitors, and epoxy compounds to the reaction solution before the distillation operation.

2. 2. The method for producing 1-adamantanecarboxylic acid chloride according to claim 1, wherein the Lewis base is at least one selected from the group consisting of organic phosphorus compounds, organic amine compounds, and organic sulfur compounds.

3. 3. The method for producing 1-adamantanecarboxylic acid chloride according to claim 1, wherein the active methylene compound is selected from the group consisting of malonic acid diesters, acetoacetic acid esters, malononitrile, cyanoacetic acid esters, and 1,3-cycloalkanedione.

4. 3. The method for producing 1-adamantanecarboxylic acid chloride according to claim 1, wherein the polycyclic aromatic hydrocarbon is selected from the group consisting of acenes, fullerenes, pyrenes, perylenes, and derivatives thereof.

5. The method for producing 1-adamantanecarboxylic acid chloride according to claim 1 or 2, wherein the polymerization inhibitor is selected from the group consisting of 3,5-di-t-butyl-4-hydroxytoluene, 2,6-di-t-butylphenol, di-t-butyl-7-phenylquinone methide, and 2,2-diphenyl-1-picrylhydrazyl.

6. 3. The method for producing 1-adamantanecarboxylic acid chloride according to claim 1, wherein the epoxy compound is selected from the group consisting of 1,2-epoxyoctadecane, 1,5-hexadiene diepoxide, and 1,7-octadiene diepoxide.

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