High-purity 2-aminoethyl methacrylate hydrochloride, copolymer containing the same as a constitutional unit, and method for producing 2-aminoethyl methacrylate hydrochloride

Abstract

The method for producing 2-aminoethyl methacrylate hydrochloride of the present invention includes: a reaction step of reacting aminoethanol hydrochloride with methacryloyl chloride; and a drying step of drying 2-aminoethyl methacrylate hydrochloride obtained in the reaction step at 45°C or lower.

Description

Technical Field

[0001] This invention relates to high-purity 2-aminoethyl methacrylate hydrochloride, copolymers containing the hydrochloride as a constituent unit, and a method for manufacturing 2-aminoethyl methacrylate hydrochloride. Background Technology

[0002] For example, as described in Patent Documents 1 and 2, the compound shown in Formula (1) is a useful compound that can be used as a raw material for polymers used for surface treatment of contact lenses and polymers used for contact lens care solutions.

[0003]

Chemical Formula 1

[0004] In equation (1), a:b = 50:50 to 98:2. 1 X is a hydrogen atom or a methyl group. 1 It can be O or NH.

[0005] The compound shown in formula (1) above can be obtained, for example, by polymerizing the compound shown in formula (2) with 2-aminoethyl methacrylate hydrochloride (AEMA) shown in formula (3) using a free radical polymerization method or the like.

[0006]

Chemical Formula 2

[0007] In equation (2), R 2 X is a hydrogen atom or a methyl group. 2 It can be O or NH.

[0008]

Chemical Formula 3

[0009] AEMA can be manufactured, for example, by the method described in Non-Patent Document 1. Specifically, it can be obtained by reacting ethanolamine hydrochloride with methacrylamide chloride, purifying it with diethyl ether, filtering, and drying. Existing technical documents Non-patent literature

[0010] Non-patent literature 1: Journal of Polymer Science, Part A: Polymer Chemistry (2013), 51 (21), 4522-4529. Patent documents

[0011] Patent Document 1: International Publication No. 2019 / 111838 Patent Document 2: International Publication No. 2021 / 070862 Summary of the Invention The problem the invention aims to solve

[0012] In conventional manufacturing methods (the manufacturing method described in Non-Patent Document 1), there are steps that do not describe detailed conditions for the manufacture of AEMA. When manufacturing AEMA based on this method, a homopolymer of AEMA as shown in formula (4) is sometimes produced as a byproduct and included in the AEMA (in the AEMA composition). Removing the AEMA homopolymer from the AEMA is difficult, so it is necessary to reduce its byproduct yield. That is, in the manufacturing method described in Non-Patent Document 1, it is difficult to stably manufacture high-purity AEMA.

[0013] [Chemical Formula 4]

[0014] In equation (4), n is between 20 and 30,000.

[0015] When AEMA contains a homopolymer of AEMA (in an AEMA composition), it is difficult to completely remove it through purification. When AEMA containing a homopolymer of AEMA is used as a building block of the compound (polymer) shown in Formula (1), the compound shown in Formula (1) will contain the homopolymer of AEMA. Due to the presence of the homopolymer of AEMA in the compound shown in Formula (1), the safety of the compound shown in Formula (1) may be reduced. When the compound shown in Formula (1) containing the homopolymer of AEMA is used for contact lens applications, the desired effect may not be achieved because the homopolymer of AEMA inhibits the reaction of the compound shown in Formula (1) or the homopolymer of AEMA itself reacts. Therefore, in view of the above circumstances, the present invention aims to provide high-purity 2-aminoethyl methacrylate hydrochloride, copolymers containing the hydrochloride as a constituent unit or substantially composed of the hydrochloride, and a method for manufacturing 2-aminoethyl methacrylate hydrochloride. Solution for solving the problem

[0016] In order to achieve the above objectives, the inventors conducted in-depth research and found that high-purity AEMA can be obtained by drying AEMA under specific drying conditions during the manufacturing process of AEMA.

[0017] That is, the present invention is as follows. 1. A 2-aminoethyl methacrylate hydrochloride, wherein, The content of homopolymer of 2-aminoethyl methacrylate hydrochloride is less than 2 mol. 2. An aminoethyl methacrylate hydrochloride, wherein, It is essentially a homopolymer that does not contain 2-aminoethyl methacrylate hydrochloride. 3. 2-Aminoethyl methacrylate hydrochloride according to claim 1 or 2 above, wherein, For a solution obtained by dissolving the 2-aminoethyl methacrylate hydrochloride in ethanol at 10% by weight, the transmittance at a wavelength of 555 nm was measured using a spectrophotometer and was greater than 50%. 4. A method for manufacturing 2-aminoethyl methacrylate hydrochloride as described in item 1 above, comprising the following steps: Reaction step 1, which involves reacting 2-aminoethanol hydrochloride with methacryloyl chloride, and... Drying step 2 involves subjecting the 2-aminoethyl methacrylate hydrochloride obtained from reaction step 1) to vacuum drying at a temperature below 45°C. 5. The manufacturing method according to item 4 above, wherein, The pressure reduction is below 100 hPa. 6. The manufacturing method according to item 4 or 5 above, wherein, A crystallization process is included between process 1) and process 2). 7. The manufacturing method according to item 4 or 5 above, wherein, The 2-aminoethyl methacrylate hydrochloride contains less than 2 mol% of a homopolymer of 2-aminoethyl methacrylate hydrochloride. 8. The manufacturing method according to item 4 or 5 above, wherein, The 2-aminoethyl methacrylate hydrochloride is substantially free of homopolymer of 2-aminoethyl methacrylate hydrochloride. 9. A copolymer, wherein, It contains 2-aminoethyl methacrylate hydrochloride as a constituent unit as described in item 1 or 2 above, and a compound represented by formula (2) as a constituent unit.

[0018] [Chemical Formula 5]

[0019] (In equation (2), R) 2 X is a hydrogen atom or a methyl group. 2 (For O or NH.) 10. A copolymer of formula (1), wherein, The copolymer contains the constituent units of 2-aminoethyl methacrylate hydrochloride as described in item 1 or 2 above, and the constituent units of the compound shown in formula (2).

[0020]

Chemical Formula 6

[0021] (In formula (1), a:b = 50:50 to 98:2, R) 1 X is a hydrogen atom or a methyl group. 1 (For O or NH.)

[0022] [Chemical Formula 7]

[0023] (In equation (2), R) 2 X is a hydrogen atom or a methyl group. 2 (For O or NH.) Invention Effects

[0024] The present invention can provide high-purity 2-aminoethyl methacrylate hydrochloride and a method for manufacturing the hydrochloride. Detailed Implementation

[0025] The method for manufacturing 2-aminoethyl methacrylate hydrochloride of the present invention will be further described in detail below. The high-purity 2-aminoethyl methacrylate hydrochloride obtained by the method of the present invention is referred to as the 2-aminoethyl methacrylate hydrochloride of the present invention. The method for manufacturing 2-aminoethyl methacrylate hydrochloride of the present invention includes at least the following reaction step 1) and drying step 2), but may also include other steps. The purity of AEMA can be determined by... 1 It is determined by ¹H NMR and transmittance. 1 ¹H NMR can determine the AEMA homopolymer contained in AEMA, and transmittance can be used to evaluate even smaller amounts of impurities. In this specification, when preferred numerical ranges (e.g., ranges for concentration, weight-average molecular weight, or number-average molecular weight) are described in the form of ranges, the lower and upper limits of each numerical range can be freely combined. For example, in the description "preferably 10 or more, more preferably 20 or more, and preferably 100 or less, more preferably 90 or less," "preferably lower limit: 10" and "more preferably upper limit: 90" can be combined to obtain "10 or more and 90 or less." Similarly, in a description such as "preferably 10 to 100, more preferably 20 to 90," it can also be combined to form "10 to 90."

[0026] (Reaction process) AEMA can be obtained by reacting 2-aminoethanol hydrochloride with methacryloyl chloride. In the reaction of 2-aminoethanol hydrochloride with methacryloyl chloride, the amount of methacryloyl chloride used is preferably 1.0 mole or more relative to 1 mole of 2-aminoethanol hydrochloride. More preferably, it is 1.1 to 5.0 moles, and even more preferably, it is 1.2 to 2.0 moles. If it is less than 1.0 mole, aminoethanol hydrochloride will remain, which is not preferred. Using more than 5.0 moles is uneconomical, and in addition, it may be difficult to remove unreacted methacryloyl chloride. The above reaction preferably involves melting 2-aminoethanol hydrochloride without using a solvent. Therefore, the reaction temperature is preferably 80°C or higher, more preferably 85°C or higher, and even more preferably 90°C or higher. Below 80°C, the reaction may not proceed sufficiently. The above reaction is preferably carried out without a solvent, but a solvent may also be used. If a solvent is used, it is preferably a solvent that does not react with methacryloyl chloride, such as dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, etc. In the above reaction, hydrogen chloride is generated as the reaction proceeds. Therefore, it is preferable to blow in an inert gas to remove the hydrogen chloride while the reaction is underway. Examples of inert gases include nitrogen and argon, with nitrogen being the preferred choice. The above reaction is preferably carried out by adding methacryloyl chloride dropwise. By adding dropwise, the amount of heat of reaction and hydrogen chloride generated by the reaction can be easily controlled. In the above reaction, a polymerization inhibitor can be added as needed. As a polymerization inhibitor, any inhibitor conventionally used in free radical polymerization is acceptable, with no particular limitation. Examples include hydroquinone, hydroquinone monomethyl ether, 2-tert-butylhydroquinone, 4-methoxyphenol, 2,6-di-tert-butyl-4-methylphenol (BHT), phenothiazine, etc. These polymerization inhibitors can be used alone or in combination of two or more. The amount of polymerization inhibitor is not particularly limited, but relative to the mass of methacryloyl chloride, it is preferably from 100 ppm to 50,000 ppm, more preferably from 1,000 ppm to 40,000 ppm, and even more preferably from 5,000 ppm to 30,000 ppm. The reaction time, including the addition time of methacryloyl chloride, is preferably 12 hours or less, more preferably 8 hours or less, further preferably 6 hours or less, particularly preferably 3 hours or less, and most preferably 2 hours or less. If the reaction time is too long, the amount of byproducts may increase. If the reaction is cooled directly after completion, the reaction solution will solidify and its operability will deteriorate. Therefore, it is preferable to dilute it with a solvent. Preferred solvents include acetates such as methyl acetate, ethyl acetate, and butyl acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and butanol. Two or more solvents can also be mixed.

[0027] (Crystallization process) The method for manufacturing 2-aminoethyl methacrylate hydrochloride of the present invention preferably includes a crystallization step between the above-described reaction step 1) and the drying step 2) described below. The crystallization process refers to the operation of crystallizing, separating, and purifying the 2-aminoethyl methacrylate hydrochloride containing impurities (such as AEMA homopolymer) and unreacted raw materials obtained in reaction step 1) above through cooling or heating. There are no particular limitations on this process. In addition, this process may also include well-known operations such as extraction, purification, and filtration. Good solvents for crystallization include alcohols such as methanol, ethanol, 1-propanol, and 2-propanol; two or more solvents can also be mixed. Poor solvents include acetates such as methyl acetate, ethyl acetate, and butyl acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; hydrocarbons such as hexane and heptane; and aromatic compounds such as toluene; two or more solvents can also be mixed. To improve the purity, the above crystallization process can be performed multiple times, or the crystals can be washed with the above solvent. After crystallization, the precipitated crystals can be recovered by filtration. Examples of filtration methods include thermal filtration, gravity filtration, vacuum (suction) filtration, and pressure filtration, with pressure filtration being the preferred method. The crystallization process is not particularly limited, but it can be exemplified as follows: crystallization → pressure filtration → obtaining the first crude crystal → re-dissolving → hot filtration → crystallization → pressure filtration → obtaining the second crude crystal → washing with mixed solvent → obtaining the third crude crystal.

[0028] (Drying process) The crystals recovered in the above reaction step 1) or the above crystallization step contain the organic solvent used for crystallization. Therefore, they are finally dried at a temperature below 45°C to obtain AEMA powder. The drying temperature is preferably 20°C or higher and 45°C or lower, more preferably 30°C or higher and 40°C or lower. If the temperature is below 20°C, the solvent may not be completely removed, and if the temperature is above 45°C, a homopolymer of AEMA may be formed. Drying is preferably carried out under reduced pressure. Reducing pressure shortens the drying time and also reduces residual solvent. The pressure is not particularly limited, but is preferably below 100 hPa, more preferably below 50 hPa, further preferably below 20 hPa, and particularly preferably below 10 hPa. There is no particular limitation on the drying time, but it is preferably more than 1 hour and less than 24 hours. If it is less than 1 hour, the solvent may not be completely removed, and if it exceeds 24 hours, the efficiency will be low. For example, 1 to 10 hours or 2 to 8 hours. The loss on drying of AEMA is preferably 2.0 wt% or less, more preferably 1.0 wt%, further preferably 0.5 wt%, particularly preferably 0.3 wt% or less, and even more preferably 0.2 wt% or less. If more than 2.0 wt% of volatile components (solvent, moisture) remain, the stability and workability may deteriorate.

[0029] (The 2-aminoethyl methacrylate hydrochloride of the present invention) The method for manufacturing 2-aminoethyl methacrylate hydrochloride of the present invention can yield 2-aminoethyl methacrylate hydrochloride (composition) containing less than 2 mol%, less than 1.5 mol%, less than 1.0 mol%, less than 0.5 mol%, less than 0.3 mol%, less than 0.2 mol%, less than 0.1 mol%, less than 0.05 mol%, or less than 0.01 mol% of the homopolymer of AEMA shown in formula (4). Furthermore, the method for manufacturing 2-aminoethyl methacrylate hydrochloride of the present invention can yield 2-aminoethyl methacrylate hydrochloride (composition) that is substantially free of the homopolymer of AEMA shown in formula (4). It should be noted that "substantially free" means below the detection limit of a known measuring device. It should be noted that the above mole % refers to the molar ratio of the homopolymer of AEMA to the total moles of 2-aminoethyl methacrylate hydrochloride and impurities (especially the homopolymer of AEMA).

[0030] Furthermore, the 2-aminoethyl methacrylate hydrochloride of the present invention exhibits high solubility in ethanol. When the transmittance of a 10 wt% ethanol solution at a wavelength of 555 nm was measured using a spectrophotometer, its transmittance was 50% or more, preferably 60% or more, more preferably 70% or more, further preferably 80% or more, even more preferably 90% or more, most preferably 95% or more, and even more preferably 97% or more.

[0031] (The compound shown in formula (2)) The monomer represented by formula (2) in this invention can be manufactured by known methods, for example, by reacting a hydroxyl-containing polymeric monomer with 2-bromoethylphosphoryl dichloride in the presence of a tertiary base, and then reacting the resulting compound with a tertiary amine. Alternatively, it can be done by reacting a hydroxyl-containing polymeric monomer with a cyclic phosphorus compound to obtain a cyclic compound, and then performing a ring-opening reaction with a tertiary amine. X 2 When R is an oxygen atom, from the perspective of polymerizability and stability, 2 Methyl is preferred. X 2 When R is NH, from the point of view of aggregation, 2 Hydrogen atoms are preferred. As a preferred example of the compound shown in formula (2), X can be cited: 2 2-(meth)acryloyloxyethyl (2-(trimethylammonium)ethyl) phosphate with oxygen atom, X 2 2-(meth)acrylamidoethyl (2-(trimethylammonium)ethyl) phosphate of NH; more preferably R 2 It is methyl and X 2 2-Methacryloxyethyl (2-(trimethylammonium)ethyl) phosphate (MPC), R, with oxygen atoms 2 It is a hydrogen atom and X 2 2-Acrylamidoethyl (2-(trimethylammonium)ethyl) phosphate of NH; from the perspective of availability, 2-methacryloyloxyethyl (2-(trimethylammonium)ethyl) phosphate is further preferred.

[0032] (Method for manufacturing the compound shown in formula (1)) The compound shown in formula (1) can be obtained by copolymerizing the 2-aminoethyl methacrylate hydrochloride of the present invention, which is a constituent unit, with the compound shown in formula (2), which is a constituent unit. For example, the compound shown in formula (1) is a polymer (copolymer) of polymerizable unsaturated groups of each constituent unit. The above polymerization reaction can be carried out in the presence of a free radical polymerization initiator, under an atmosphere purged with inert gases such as nitrogen, carbon dioxide, argon, or helium, or under an inert gas atmosphere, via free radical polymerization (e.g., known methods such as bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization). From a purification perspective, solution polymerization is preferred. The copolymer can be purified using common purification methods such as reprecipitation, dialysis, and ultrafiltration. Examples of free radical polymerization initiators include azo-based free radical polymerization initiators, organic peroxides, and persulfates. Examples of azo-based free radical polymerization initiators include: 2,2'-azobis(2-methylpropanediamine) dihydrochloride (V-50), 2,2-azobis(2-diaminopropyl) dihydrochloride, 2,2-azobis(2-(5-methyl-2-imidazolin-2-yl)propane) dihydrochloride, 4,4'-azobis(4-cyanopentanoic acid), 2,2-azobisisobutylamide dihydrate, 2,2-azobis(2,4-dimethylpentanonitrile), and 2,2-azobisisobutyronitrile (AIBN). 2,2'-azobis(2-methylpropanediamine) dihydrochloride (V-50) is more preferred. Examples of organic peroxides include: tert-butyl peroxyneodecanate (Perbutyl (registered trademark) ND), benzoyl peroxide, diisopropyl peroxydicarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanate, tert-butyl peroxydiisobutyrate, lauroyl peroxide, and succinic acid peroxide (succinyl peroxide). Examples of persulfates include ammonium persulfate, potassium persulfate, and sodium persulfate. These free radical polymerization initiators can be used alone or in combination of two or more. The amount of polymerization initiator used is typically 0.001 to 10 parts by weight, preferably 0.01 to 5.0 parts by weight, relative to 100 parts by weight of the monomer composition of the copolymer (the compound shown in formula (1)).

[0033] The polymerization reaction can be carried out in the presence of a solvent. This solvent can be one capable of dissolving the monomer composition that forms the constituent units without reacting with the monomer composition. Examples include water, alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and diethyl ketone; esters such as ethyl acetate; linear or cyclic ethers such as ethyl cellosolve, tetrahydrofuran, and N-methylpyrrolidone; and nitrogen-containing solvents such as acetonitrile and nitromethane. Preferably, water, an alcohol, or a mixture thereof is used, with water being more preferred. The weight-average molecular weight of the compound represented by formula (1) obtained above is 10,000 to 2,000,000, preferably 100,000 to 1,000,000, more preferably 150,000 to 600,000, and even more preferably 200,000 to 450,000. In formula (1), the molar ratio of a to b can be set arbitrarily, but it is preferred that a:b = 50:50 to 98:2, more preferably a:b = 80:20 to 95:5, and even more preferably a:b = 88:12 to 94:6.

[0034] The present invention will be specifically described below through embodiments, but the present invention is not limited to the following embodiments.

[0035] <Determination of Homopolymer Content in AEMA> Perform the measurement according to the following steps. AEMA 1 ¹H NMR determination. The determination conditions are recorded below. The results... 1 The peak area value from AEMA observed near 6.2 ppm in the 1H NMR spectrum is denoted as A. m The broad peak area values ​​observed in the vicinity of 0.4 ppm to 1.0 ppm from AEMA homopolymers will be denoted as A. pThe content of the compound shown in formula (4) can be calculated using the following formula (1). (A) p / 3) / (A m +(A p / 3)))×100 …Calculation formula (1) 3: Peak area A p number of protons 1 H NMR measurement conditions Device: ECS400 (manufactured by Nippon Electronics Corporation) Solvent: Deuterated dimethyl sulfoxide Sample concentration: 3% Total number of times: 32

[0036] <Determination of Loss on Drying (Method for Determination of Residual Solvent Content)> Perform the measurement according to the following steps. Weigh the tare weight of the spiral tube and record the weight as W. 1 Weigh 1g of AEMA into the spiral tube, and record the sum of the weights of the spiral tube and AEMA as W. 2 Dry in an oven at 125°C for 4 hours. After drying, cover the spiral tube and cool to room temperature in a desiccator. After cooling, remove from the desiccator, remove the cover, weigh, and record the weight as W. 3 The loss on drying (%) is calculated using the following formula (2). (W) 2 -W 3 ) / (W 2 -W 1 ) × 100 … Calculation formula (2)

[0037] Purity determination based on transmittance Perform the measurement according to the following steps. Adjustment of the test solution Weigh 0.3g of AEMA and 2.7g of ethanol (ultra-dehydrated) (manufactured by Fujifilm and Koichi Chemical Co., Ltd.) into a spiral tube, stir for 10 minutes, and use this as the test solution. transmittance measurement Ethanol (ultra-dehydrated) was added to a cuvette with a 1 cm optical path length, and background measurements were performed in the wavelength range of 400 nm to 750 nm. Then, the test solution was transferred to another cuvette with a 1 cm optical path length, and spectral measurements were performed in the wavelength range of 400 nm to 750 nm to evaluate the transmittance at 555 nm. Other conditions are shown below. transmittance measurement conditions Apparatus: V-650 UV-Vis spectrophotometer (manufactured by Japan Spectrophotometer Co., Ltd.) Response: Medium Bandwidth: 2.0nm Scan speed: 200 nm / min As a purity measure based on light transmittance, the following score is set, with a lower score indicating higher purity. Light transmittance of 75% or higher: Rating "1" Light transmittance above 50% and below 75%: Rating "2" Light transmittance above 0 and below 50%: Rating "3"

[0038] <Determination of weight-average molecular weight> The obtained copolymer was dissolved in ion-exchanged water to a concentration of 0.1 wt%, and the weight-average molecular weight was determined by gel permeation chromatography (GPC). Column: Shodex (GSM-700) Mobile phase: 0.1 mol / L sodium sulfate aqueous solution Standard reference material: Pulllan Measuring instrument: Differential refractive index detector RI-8020 (manufactured by Tosoh Corporation) Method for calculating weight-average molecular weight: Molecular weight calculation program (SC-8020 uses GPC program) Flow rate: 1.0 mL per minute Injection volume: 100μL Column oven temperature: 40℃ Measurement time: 30 minutes

[0039] <Cytotoxicity assay using rabbit corneal epithelial cells (SIRC cells)> The cytotoxicity assays using SIRC cells were performed in accordance with ISO 10993-5:2009 and reference N. Tani et al. Toxicology in vitro 13 (1999) 175-187, and cell viability was determined and evaluated.

[0040] • Preparation of culture medium for SIRC cell culture Add 5 mL of antibiotic-antifungal solution (100×) to a 500 mL Durbeco Modified Eagle Medium (DMEM) bottle. Then, add 50 mL of sterilized fetal bovine serum (FBS, inactivated) after thawing at 4°C to prepare the cell culture medium. Durbeco Modified Eagle Medium (DMEM) was a product of Sigma-Aldrich Japan, the antibiotic-antifungal agent (100×) was penicillin-streptomycin (100×) manufactured by Sigma-Aldrich Japan, and the sterilized fetal bovine serum (FBS) was a product of Japan Biological Testing Institute Co., Ltd.

[0041] • SIRC cell culture Add 9 mL of cell culture medium and 1 mL of cell suspension to a sterile culture dish, and incubate in a CO2 incubator for at least 48 hours to allow cell proliferation. Observe the cells in the culture dish under a microscope to confirm the increase in cell number and cell status (whether the cells are dead or floating instead of adhering to the wall).

[0042] • Cell inoculation The concentration of the cell suspension was adjusted to 1×10 using cell culture medium. 5 Cells / mL. Using a micropipette, dispense 100 μL of the adjusted cell suspension into each well of a 96-well plate and incubate for 24 hours in a CO2 incubator.

[0043] • Preparation of test substances The test substances were prepared by dissolving 10 w / v% solutions of each copolymer and sodium dodecyl sulfate (SDS) for biochemical purposes as a positive control in cell culture medium. The prepared test substance was diluted in stages on a 96-well plate to 100 w / v%, 75 w / v%, 50 w / v%, 25 w / v%, 12.5 w / v%, and 0 w / v for evaluation. Sodium dodecyl sulfate for biochemical applications uses products from Fujifilm and Koichi Pure Chemical Industries, Ltd., while Durbeco phosphate-buffered saline uses products from Sigma-Aldrich Japan.

[0044] • Exposure to the test substance Remove the culture medium for SIRC cell culture from the 96-well plate and add the prepared test substance at 200 μL / well to the 96-well plate that has been cultured for 24 hours. Expose the plate to CO2 for 24 hours.

[0045] • Cytotoxicity assessment using the neutral red (NR) method Dissolve NR in ion-exchanged water to a concentration of 5 mg / mL to prepare NR stock solution. Dilute the NR stock solution 100-fold with cell culture medium to prepare NR medium. Remove the 96-well plate that has been exposed to the test substance and remove the medium. Then, add 100 μL of NR medium per well and incubate in a CO2 incubator for 3 hours to allow cells to take up NR. Remove the 96-well plate from the CO2 incubator and remove the NR medium. Add PBS to the 96-well plate at 100 μL / well, then remove the PBS. Using a micropipette, add NR extraction solution (a mixture of 50% ethanol, 49% deionized water, and 1% acetic acid) at 100 μL / well. Stir for 5 minutes to extract NR from the cells and measure the absorbance at 540 nm using a microplate reader. The SDS exposure concentration was confirmed to be approximately 0.01% by mass when cell viability was 50%. The cell viability and IC50 after treatment with the test substance were calculated using the following formula. 50 value. Neutral Red uses products from Fujifilm and Kojun Pharmaceutical Co., Ltd. • Formula for calculating cell viability Cell viability (%) = (Absorbance of test substance treatment - Absorbance of blank) / (Absorbance of culture medium treatment - Absorbance of blank) × 100 •IC 50 The formula for calculating the value IC 50 Value = 10 （log10（A / B）×（50-C） / （D-C）＋log10（B）） A: Higher concentrations (w / v%) of the test substance sandwiched between 50% cell viability. B: Lower concentrations of the test substance (w / v%) sandwiched between cells with a 50% viability threshold. C: Cell viability at B concentration D: Cell viability at concentration A The absorbance of culture medium treatment is the absorbance when only culture medium is added to the wells of inoculated cells.

[0046] The following rating system is established as a standard for judging safety. IC 50 A score of 50 or higher: a rating of "1" (indicating extremely high safety). IC 50 A score of 25 or higher but lower than 50: a rating of "2" (indicating excellent safety). IC 50 A score of 12.5 or higher but lower than 25: Rating "3" (No safety issues) IC 50 Values ​​above 0 and below 12.5: Rating "4" (More detailed safety testing required)

[0047] <Example 1-1> • AEMA synthesis performed by the manufacturing method of the present invention To a four-necked flask equipped with a thermometer, stirrer, dropping funnel, and reflux tube, add 50.0 g (0.51 mol) of 2-aminoethanol hydrochloride and 1.02 g of phenothiazine (approximately 12800 ppm by mass relative to methacryloyl chloride). Stirring is initiated, and the temperature is raised to 90°C to melt the 2-aminoethanol hydrochloride. The reaction is continued by adding 79.8 g (0.76 mol) of methacryloyl chloride dropwise over 3 hours (hr). After the reaction is complete, the mixture is cooled to approximately 60°C, and 530 g of ethyl acetate is added. After the addition of ethyl acetate, the mixture is further cooled to room temperature for crystallization. The crystals are filtered under pressure at 0.02 MPa using No. 5A filter paper (manufactured by Toyo Filter Paper Co., Ltd.) in a nitrogen atmosphere to obtain crude crystals (A). To the obtained crude crystals (A), add 1.02 g of phenothiazine, 140 g of 2-propanol, and 370 g of ethyl acetate, and heat to 80°C to dissolve them. After confirming dissolution, insoluble matter was removed by pressurized hot filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper, and the filtrate was recovered. The filtrate was cooled to room temperature and then further cooled to -5°C for crystallization. This was done by pressurized filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper to obtain crude crystals (B). The crude crystals (B) were washed with a mixed solvent of 70 g of 2-propanol and 185 g of ethyl acetate, and then filtered to obtain crude crystals (C). The obtained coarse crystals (C) were dried under reduced pressure (20 hPa) at 35 °C for 5 hours to obtain the target AEMA. The weight loss during drying was 0.3 wt%. use 1 H NMR analysis confirmed that the compound shown in formula (4) was not detectable in AEMA. Furthermore, the transmittance was measured, and the transmittance at 555nm was 81%.

[0048] <Examples 1-2> 100.0 g (1.02 mol) of 2-aminoethanol hydrochloride and 2.04 g of phenothiazine (approximately 12800 ppm by mass relative to methacryloyl chloride) were added to a four-necked flask equipped with a thermometer, stirrer, dropping funnel, and reflux tube. Stirring was initiated, and the temperature was raised to 92 °C to melt the 2-aminoethanol hydrochloride. 159.6 g (1.52 mol) of methacryloyl chloride was added dropwise over 5 hours to initiate the reaction. After the reaction was complete, the mixture was cooled to approximately 60 °C, and 530 g of ethyl acetate was added. After the addition of ethyl acetate, the mixture was further cooled to room temperature for crystallization. The crystals were filtered under pressure at 0.02 MPa using No. 5A filter paper to obtain crude crystals (A). 2.04 g of phenothiazine, 280 g of 2-propanol, and 740 g of ethyl acetate were added to the obtained crude crystals (A), and the mixture was heated to 80 °C to dissolve them. After confirming dissolution, insoluble matter was removed by pressurized hot filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper, and the filtrate was recovered. The filtrate was cooled to room temperature, then further cooled to -5°C for crystallization. Crystallization was performed by pressurized filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper to obtain crude crystals (B). The crude crystals (B) were washed with a mixed solvent of 140 g of 2-propanol and 370 g of ethyl acetate, and then filtered to obtain crude crystals (C). The obtained crude crystals (C) were dried under reduced pressure (80 hPa) at 40 °C for 8 hours to obtain the target AEMA. The drying weight loss was 0.6 wt%. 1 Analysis by H NMR confirmed that the AEMA of the compound shown in formula (4) could not be detected. Furthermore, the transmittance was measured, and the transmittance at 555nm was 70%.

[0049] <Examples 1-3> To a four-necked flask equipped with a thermometer, stirrer, dropping funnel, and reflux tube, add 50.0 g (0.51 mol) of 2-aminoethanol hydrochloride and 1.02 g of phenothiazine (approximately 12800 ppm by mass relative to methacryloyl chloride). Stirring is initiated, and the temperature is raised to 90 °C to melt the 2-aminoethanol hydrochloride. 79.8 g (0.76 mol) of methacryloyl chloride is added dropwise over 2 hours to initiate the reaction. After the reaction is complete, the mixture is cooled to approximately 60 °C, and 530 g of ethyl acetate is added. After the addition of ethyl acetate, the mixture is further cooled to room temperature for crystallization. The crystals are filtered under pressure at 0.02 MPa using No. 5A filter paper in a nitrogen atmosphere to obtain crude crystals (A). 1.02 g of phenothiazine, 140 g of 2-propanol, and 370 g of ethyl acetate are added to the obtained crude crystals (A), and the mixture is heated to 80 °C to dissolve them. After confirming dissolution, insoluble matter was removed by pressurized hot filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper, and the filtrate was recovered. The filtrate was cooled to room temperature and then further cooled to -5°C for crystallization. This was done by pressurized filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper to obtain crude crystals (B). The crude crystals (B) were washed with a mixed solvent of 70 g of 2-propanol and 185 g of ethyl acetate, and then filtered to obtain crude crystals (C). The obtained crude crystals (C) were dried under reduced pressure (10 hPa) at 40 °C for 2 hours to obtain the target AEMA. The drying weight loss was 0.2 wt%. 1 Analysis by H NMR confirmed that the AEMA of the compound shown in formula (4) could not be detected. Furthermore, the transmittance was measured, and the transmittance at 555nm was 90%.

[0050] <Examples 1-4> To a four-necked flask equipped with a thermometer, stirrer, dropping funnel, and reflux tube, add 50.0 g (0.51 mol) of 2-aminoethanol hydrochloride and 1.02 g of phenothiazine (approximately 12800 ppm by mass relative to methacryloyl chloride). Stirring is initiated, and the temperature is raised to 90 °C to melt the 2-aminoethanol hydrochloride. 79.8 g (0.76 mol) of methacryloyl chloride is added dropwise over 2 hours to initiate the reaction. After the reaction is complete, the mixture is cooled to approximately 60 °C, and 530 g of ethyl acetate is added. After the addition of ethyl acetate, the mixture is further cooled to room temperature for crystallization. The crystals are filtered under pressure at 0.02 MPa using No. 5A filter paper in a nitrogen atmosphere to obtain crude crystals (A). 1.02 g of phenothiazine, 140 g of 2-propanol, and 370 g of ethyl acetate are added to the obtained crude crystals (A), and the mixture is heated to 80 °C to dissolve them. After confirming dissolution, insoluble matter was removed by pressurized hot filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper, and the filtrate was recovered. The filtrate was cooled to room temperature and then further cooled to -5°C for crystallization. This was done by pressurized filtration at 0.02 MPa under a nitrogen atmosphere using No. 5A filter paper to obtain crude crystals (B). The crude crystals (B) were washed with a mixed solvent of 70 g of 2-propanol and 185 g of ethyl acetate, and then filtered to obtain crude crystals (C). The obtained crude crystals (C) were dried under reduced pressure (40 hPa) at 25 °C for 5 hours to obtain the target AEMA. The drying loss was 1.0 wt%. 1 Analysis by H NMR confirmed that the AEMA of the compound shown in formula (4) could not be detected. Furthermore, the transmittance was measured, and the transmittance at 555nm was 97%.

[0051] <Comparative Example 1-1> Coarse crystals (C) of AEMA were obtained by following the same steps as in Examples 1-2. The obtained coarse crystals of AEMA (C) were dried under reduced pressure (30 hPa) at 50 °C for 4 hours. Using... 1 H NMR analysis confirmed that the homopolymer contained 3.2 mol of AEMA as shown in formula (4). Furthermore, when it was dissolved in ethanol for transmittance measurement, precipitates were found, so transmittance measurement was not performed.

[0052] <Comparative Examples 1-2> Coarse crystals (C) of AEMA were obtained by following the same steps as in Examples 1-2. The obtained coarse crystals of AEMA (C) were dried under reduced pressure (40 hPa) at 60 °C for 4 hours. Using... 1H NMR analysis confirmed that the homopolymer contained 5.5 mol of AEMA as shown in formula (4). Furthermore, when it was dissolved in ethanol for transmittance measurement, precipitates were found, so transmittance measurement was not performed.

[0053] Table 1

[0054] <Example 2-1> Synthesis of the compound shown in formula (1) In the compound shown in formula (2), R 2 For hydrogen atoms, X 2 50.0 g (0.17 mol) of 2-methacryloyloxyethyl (2-(trimethylammonium)ethyl) phosphate (MPC) (manufactured by Nippon Oil Co., Ltd.) containing an oxygen atom, and 3.1 g (0.02 mol) of 2-aminoethyl methacrylate hydrochloride (AEMA) synthesized in Examples 1-1 were dissolved in 212.0 g of distilled water. This solution was placed in a four-necked flask equipped with a reflux tube, a nitrogen inlet tube, a thermometer, and a stirrer. The solution was heated to 65°C, and 0.36 g of 2,2'-azobis(2-methylpropanediamine) dihydrochloride (V-50) (manufactured by Fujifilm and Koko Pure Chemicals Co., Ltd.) was added, while nitrogen was bubbled through at a rate of 0.3 L / min. The temperature of the solution was raised to 70°C and maintained for 120 minutes. After the reaction was complete, the solution was cooled to room temperature, purified by dialysis using a dialysis membrane, and then freeze-dried to obtain a white powder. To make the compound represented by formula (1) easier to handle, its concentration was adjusted to 10 w / v. The molecular weight was confirmed by GPC, and the weight-average molecular weight was 330,000. The molar ratio of a to b in the compound shown in formula (1) is 90:10.

[0055] <Examples 2-2 to 2-4> Except for the conditions shown in Table 2, the compound shown in formula (1) was synthesized following the same steps as in Example 2-1. In Example 2-2, the molar ratio of a to b of the compound represented by formula (1) synthesized was 95:5. The molar ratio of a to b in the compounds of formula (1) synthesized in Examples 2-3 is 92:8. The molar ratio of a to b of the compounds of formula (1) synthesized in Examples 2-4 is 85:15.

[0056] <Comparative Examples 2-1, 2-2> Except for the conditions shown in Table 2, the compound shown in formula (1) was synthesized following the same steps as in Example 2-1. In Comparative Example 2-1, the molar ratio of a to b of the compound represented by formula (1) synthesized was 90:10. In Comparative Example 2-2, the molar ratio of a to b of the compound represented by formula (1) synthesized is 90:10.

[0057] Table 2

[0058] <Example 3 and Comparative Example 3> To evaluate the safety of the compound represented by formula (1), cytotoxicity tests were performed using SIRC cells (Examples 3-1 to 3-4, Comparative Examples 3-1 and 3-2). The results are shown in Table 3.

[0059] Table 3

[0060] <Evaluation Results of the Example> In Examples 1-1 to 1-4, as shown in Table 1, AEMA with a homopolymer content of less than 2% (especially below the detection limit) can be obtained by drying at a temperature below 45°C during the drying process. Furthermore, by reducing the pressure during the drying process, drying loss can be reduced by achieving a shorter drying time. In Examples 2-1 to 2-4, compounds of formula (1) were synthesized using AEMA obtained in Examples 1-1 to 1-4 as a starting material. These compounds were evaluated in Examples 3-1 to 3-4, and the results confirmed the availability of IC. 50 The compound represented by formula (1) has high value and high safety.

[0061] <Evaluation Results of Comparative Examples> In Comparative Examples 1-1 and 1-2, as shown in Table 1, by maintaining a drying temperature of 50°C or higher during the drying process, the content of AEMA homopolymer was 3.2% or higher. Using AEMA obtained in Comparative Examples 1-1 and 1-2 as a starting material, compounds of formula (1) were synthesized in Comparative Examples 2-1 and 2-2. These compounds were evaluated in Comparative Examples 3-1 and 3-2, and the results confirmed the presence of IC. 50 The value is low, requiring more detailed security verification. Industrial availability

[0062] The manufacturing method of the present invention can obtain high-purity 2-aminoethyl methacrylate hydrochloride.

[0063] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2024-53758, filed on March 28, 2024, the contents of which are incorporated herein by reference.

Claims

1. A 2-aminoethyl methacrylate hydrochloride, wherein, The content of homopolymer of 2-aminoethyl methacrylate hydrochloride is less than 2 mol.

2. An aminoethyl methacrylate hydrochloride, wherein, It is essentially a homopolymer that does not contain 2-aminoethyl methacrylate hydrochloride.

3. The 2-aminoethyl methacrylate hydrochloride according to claim 1 or 2, wherein, For a solution obtained by dissolving the 2-aminoethyl methacrylate hydrochloride in ethanol at 10% by weight, the transmittance at a wavelength of 555 nm was measured using a spectrophotometer and was greater than 50%.

4. A method for manufacturing 2-aminoethyl methacrylate hydrochloride according to claim 1, wherein, The process includes the following steps: Reaction step 1, which involves reacting 2-aminoethanol hydrochloride with methacryloyl chloride, and... Drying step 2 involves subjecting the 2-aminoethyl methacrylate hydrochloride obtained from reaction step 1) to vacuum drying at a temperature below 45°C.

5. The manufacturing method according to claim 4, wherein, The pressure reduction is below 100 hPa.

6. The manufacturing method according to claim 4 or 5, wherein, A crystallization process is included between process 1) and process 2).

7. The manufacturing method according to claim 4 or 5, wherein, The 2-aminoethyl methacrylate hydrochloride contains less than 2 mol% of a homopolymer of 2-aminoethyl methacrylate hydrochloride.

8. The manufacturing method according to claim 4 or 5, wherein, The 2-aminoethyl methacrylate hydrochloride is substantially free of homopolymer of 2-aminoethyl methacrylate hydrochloride.

9. A copolymer, wherein, Containing 2-aminoethyl methacrylate hydrochloride as a constituent unit as claimed in claim 1 or 2, and a compound represented by formula (2) as a constituent unit, 【Chemical Formula 1】 (In equation (2), R) 2 X is a hydrogen atom or a methyl group. 2 (For O or NH).

10. A copolymer of formula (1), wherein, The copolymer contains the constituent units of 2-aminoethyl methacrylate hydrochloride as described in claim 1 or 2, and the constituent units of the compound shown in formula (2). 【Chemical Formula 2】 (In formula (1), a:b = 50:50 to 98:2, R) 1 X is a hydrogen atom or a methyl group. 1 (for O or NH). 【Chemical Formula 3】 (In equation (2), R) 2 X is a hydrogen atom or a methyl group. 2 (For O or NH).

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