Plant cell wall-dissolving agent

Abstract

Provided is a low-toxicity zwitterion which is capable of dissolving high concentrations of cellulose.　The present invention pertains to a zwitterion represented by general formula (1): R1-A-R2-(OR3)n-B (R1 represents a C1-8 straight-chain alkyl group, a C2-8 alkenyl group or a C1-8 straight-chain alkyl-(OCH2CH2)m-. A is the cationic section of the zwitterion and represents a cation selected from an imidazolium cation, a phosphonium cation, an ammonium cation, a sulfonium cation, a pyrazolium cation, a pyridinium cation, a pyrrolidinium cation, a morpholinium cation, a cyclopropenium cation and a piperidinium cation. R2 represents a C1-4 alkylene group. R3 represents a C2-4 alkylene group. m represents a number which is 1 or 2. n represents a number which is 0-10. B represents an anion selected from -SO3 -, -COO-, -P=O(OR4)O- and -OP=O(OR5)O-. R4 and R5 may be identical or different, and are alkyl groups which may have a hydrogen atom or a C1-8 hetero atom (however, when n is 0, B is -P=O(OR4)O- or -OP=O(OR5)O-)).

Description

Plant cell wall dissolving agent

[0001] The present invention relates to a plant cell wall lysing agent, and more particularly to a plant cell wall lysing agent that can be used directly for culturing microorganisms without the need to remove the lysate from the plant cell wall.

[0002] Plant biomass is an important raw material for biorefineries. Plant cell walls are primarily composed of cellulose, hemicellulose, and lignin, but these components are robust and difficult to utilize industrially. While hydrolysis is considered for industrial processing of cell walls, liquefaction of the cell walls is considered because it requires a large amount of energy. A method using ionic liquids to liquefy plant cell walls has been reported (Non-Patent Document 1). However, although this ionic liquid can dissolve the cell walls, it is difficult to remove the ionic liquid from the lysate. Therefore, even after extracting cellulose from the lysate and hydrolyzing it to glucose, the ionic liquid remains as a component, and using this glucose can adversely affect microbial fermentation. Therefore, the present inventors have used a less toxic ionic liquid (zwitterion) to dissolve cellulose, and have found and reported that the toxicity can be reduced, enabling one-pot ethanol production (Non-Patent Document 2).

[0003] J. Phy. Chem. B. 118, 10444-10459 (2014) J. Am. Chem. Soc. 139, 16052-16055 (2017)

[0004] However, it was found that dissolving cellulose using the above zwitterions results in a problem of high solution viscosity, making it impossible to dissolve high concentrations of cellulose. Therefore, the present invention aims to develop a low-toxicity zwitterion that can achieve dissolution of high concentrations of cellulose.

[0005] The present inventors conducted various studies to solve the above-mentioned problems and found that zwitterions having one or more oxyalkylene groups between the cation moiety and the anion moiety, or zwitterions whose cation moiety is a phosphate cation, are low in toxicity and can dissolve high concentrations of cellulose with low viscosity, thereby completing the present invention.

[0006] That is, the present invention provides the following inventions [1] to [8]. [1] General formula (1)

[0007]

[0008] (R 1 represents a linear alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a linear C alkyl group -(OCH2CH2)m-; A is a cation portion of a zwitterion and represents a cation selected from an imidazolium cation, a phosphonium cation, an ammonium cation, a sulfonium cation, a pyrazolium cation, a pyridinium cation, a pyrrolidinium cation, a morpholinium cation, a cyclopropenium cation, and a piperidinium cation; R 2 represents an alkylene group having 1 to 4 carbon atoms, and R 3 represents an alkylene group having 2 to 4 carbon atoms, m represents a number of 1 or 2, n represents a number of 0 to 10, and B represents -SO3 - , -COO - , -P=O(OR 4 ) O - and -OP=O(OR 5 ) O - represents an anion selected from 4 and R 5 are the same or different and are a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a heteroatom (provided that when n is 0, B is -P=O(OR 4 ) O - Or -OP=O(OR 5 ) O -[2] The zwitterion according to [1], wherein A in general formula (1) is a cation selected from imidazolium cations, pyrazolium cations, pyridinium cations, pyrrolidinium cations, and piperidinium cations. [3] The zwitterion according to [1] or [2], wherein A in general formula (1) is an imidazolium cation. [4] The zwitterion according to [1] or [2], wherein R in general formula (1) is 1 represents a linear alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or C1-4-alkyl-(OCH2CH2)m- (where m represents the number 1 or 2). [5] A zwitterion according to any one of [1] to [4], wherein n in general formula (1) is a number from 1 to 6. [6] A zwitterion according to any one of [1] to [4], wherein B in general formula (1) is -COO - [7] The zwitterion according to any one of [1] to [5], wherein n in general formula (1) is 0 to 6, and B is -P=O(OR 4 ) O - Or -OP=O(OR 5 ) O - [8] A plant cell wall dissolving agent composition containing the zwitterion described in any one of [1] to [7]. [9] A cellulose dissolving agent composition containing the zwitterion described in any one of [1] to [7].

[10] A method for dissolving the cell wall of a plant, comprising the step of contacting a composition containing the zwitterion described in any one of [1] to [7] with the plant.

[11] A method for dissolving cellulose in a cellulose-containing plant, comprising the step of contacting a composition containing the zwitterion described in any one of [1] to [7].

[0009] The zwitterions of the present invention are ionic liquids that can easily dissolve plant cell walls, typically containing high concentrations of cellulose, and are low in toxicity. Therefore, by dissolving plant cell walls using the zwitterions of the present invention, it is possible to biorefine a large amount of plant biomass, and for example, to safely and industrially produce glucose, ethanol, and other substances from plant biomass.

[0010] C1imC2P 1 The H NMR chart is shown.

[0011] One aspect of the present invention is a compound represented by general formula (1)

[0012]

[0013] (R 1 represents a linear alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a linear C alkyl group -(OCH2CH2)m-; A is a cation portion of a zwitterion and represents a cation selected from an imidazolium cation, a phosphonium cation, an ammonium cation, a sulfonium cation, a pyrazolium cation, a pyridinium cation, a pyrrolidinium cation, a morpholinium cation, a cyclopropenium cation, and a piperidinium cation; R 2 represents an alkylene group having 1 to 4 carbon atoms, and R 3 represents an alkylene group having 2 to 4 carbon atoms, m represents a number of 1 or 2, n represents a number of 0 to 10, B is the anion portion of the zwitterion, -SO3 - , -COO - , -P=O(OR 4 ) O - and -OP=O(OR 5 ) O - represents an anion selected from 4 and R 5 are the same or different and are a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a heteroatom (provided that when n is 0, B is -P=O(OR 4 ) O - Or -OP=O(OR 5 ) O - It is a zwitterion represented by the formula:

[0014] In the present invention, a zwitterion is a molecule having both a positive charge and a negative charge within a single molecule. The zwitterion of the present invention has a cationic moiety represented by A and an anionic moiety represented by B. The zwitterion of the present invention is characterized by having one or more oxyalkylene groups between the cationic moiety represented by A and the anionic moiety represented by B. By having one or more rotatable oxyalkylene structures between the cationic moiety and the anionic moiety, the cation and the anion can independently assume positions freely, thereby lowering the melting point and viscosity. The number of rotatable oxyalkylene structures between the cationic moiety and the anionic moiety is 1 to 10, where n is the repeating number of oxyethylene structures, preferably 1 to 6, and more preferably 1 to 3.

[0015] In the present invention, the alkyl group refers to a saturated chain hydrocarbon group, and includes a linear alkyl group and a branched alkyl group. Preferably, it is an alkyl group having 1 to 8 carbon atoms, and includes a linear or branched alkyl group having 1 to 8 carbon atoms. More preferably, it is a linear or branched alkyl group having 1 to 6 carbon atoms, and even more preferably, it is a linear or branched alkyl group having 1 to 4 carbon atoms. Specific examples of these alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group.

[0016] In the present invention, the alkenyl group refers to an unsaturated chain hydrocarbon group having one double bond, and includes straight-chain alkenyl groups and branched-chain alkenyl groups. Straight-chain or branched-chain alkenyl groups having 2 to 8 carbon atoms are preferred. Straight-chain or branched-chain alkenyl groups having 2 to 6 carbon atoms are even more preferred, and straight-chain or branched-chain alkenyl groups having 2 to 4 carbon atoms are even more preferred. Specific examples of these alkenyl groups include vinyl groups, 1-propenyl groups, 2-propenyl groups (allyl groups), butenyl groups, pentenyl groups, and hexenyl groups.

[0017] In the present invention, the alkylene group refers to a divalent saturated chain hydrocarbon group, including straight-chain and branched-chain alkylene groups. It is preferably a straight-chain or branched-chain alkylene group having 1 to 4 carbon atoms, and more preferably a straight-chain or branched-chain alkylene group having 2 to 4 carbon atoms. Specific examples include a methylene group, an ethylene group, a trimethylene group, a propylene group, and a tetramethylene group.

[0018] R 1 represents a linear alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a C1-8 linear alkyl-(OCH2CH2)m-. The linear alkyl group having 1 to 8 carbon atoms is preferably a linear alkyl group having 1 to 6 carbon atoms, and more preferably a linear alkyl group having 1 to 4 carbon atoms. Specific examples of these alkyl groups include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Of these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group are preferred, and a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are more preferred. An alkenyl group having 2 to 8 carbon atoms includes a linear or branched alkenyl group having 2 to 8 carbon atoms. Preferably, it is a linear or branched alkenyl group having 2 to 6 carbon atoms, more preferably a linear or branched alkenyl group having 2 to 4 carbon atoms. Of these, vinyl, propenyl, butenyl, pentenyl, and hexenyl groups are preferred, and vinyl, 1-propenyl, 2-propenyl (allyl), and butenyl groups are more preferred.

[0019] In the group represented by C1-8 linear alkyl-(OCH2CH2)m-, the C1-8 linear alkyl group is preferably a linear alkyl group having 1 to 6 carbon atoms, and more preferably a linear alkyl group having 1 to 4 carbon atoms. Specific examples of these alkyl groups include methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl. Of these, methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl are preferred, and methyl, ethyl, n-propyl, and n-butyl are more preferred. m is a number of 1 or 2.

[0020] A is a cation moiety of the zwitterion and represents a cation selected from imidazolium cation, phosphonium cation, ammonium cation, sulfonium cation, pyrazolium cation, pyridinium cation, pyrrolidinium cation, morpholinium cation, cyclopropenium cation and piperidinium cation. Among these cations, imidazolium cation, ammonium cation, pyrazolium cation, pyridinium cation, pyrrolidinium cation, morpholinium cation and piperidinium cation are preferred, imidazolium cation, pyrazolium cation, pyridinium cation, pyrrolidinium cation and piperidinium cation are more preferred, and imidazolium cation is even more preferred.

[0021] R 2 represents an alkylene group having 1 to 4 carbon atoms, including a linear or branched alkylene group having 1 to 4 carbon atoms. Specific examples include a methylene group, an ethylene group, a trimethylene group, a propylene group, and a tetramethylene group.

[0022] R 3 Examples of the alkylene group include linear or branched alkylene groups having 2 to 4 carbon atoms, and specific examples thereof include an ethylene group, a trimethylene group, a propylene group, and a tetramethylene group. 3 The anion moiety is preferably an oxyethylene group, an oxytrimethylene group, an oxypropylene group, or an oxytetramethylene group. -or -COO - In this case, n is preferably a number from 1 to 10, more preferably a number from 1 to 8, even more preferably a number from 1 to 6, and even more preferably a number from 1 to 4. 4 ) O - Or -OP=O(OR 5 ) O - In this case, n is preferably a number from 0 to 10, more preferably from 0 to 8, even more preferably from 0 to 6, and even more preferably from 0 to 4.

[0023] B is the anion portion of the zwitterion, -SO3 - , -COO - , -P=O(OR 4 ) O - and -OP=O(OR 5 ) O - represents an anion selected from 4 and R 5 are the same or different and are hydrogen atoms or alkyl groups having 1 to 8 carbon atoms which may have a heteroatom. 4 and R 5 is preferably a hydrogen atom, a methyl group, an ethyl group, or the like. - , -P=O(OR 4 ) O - and -OP=O(OR 5 ) O - When n is 0, the anion is preferably selected from -P=O(OR 4 ) O - Or -OP=O(OR 5 ) O - is preferred.

[0024] Specific examples of the zwitterion represented by general formula (1) include the compounds shown in Table 1 below.

[0025]

[0026] The zwitterion represented by general formula (1) can be produced, for example, according to the following reaction scheme.

[0027]

[0028] (In the formula, R 5represents an alkyl group or an aromatic hydrocarbon group, and R 6 represents an alkyl group, a halogenoalkyl group, or an aromatic hydrocarbon group; A, B, and R 1 , R 2 , R 3 and n have the same meaning as above.

[0029] R 5 represents an alkyl group or an aromatic hydrocarbon group. Here, examples of the alkyl group include linear or branched alkyl groups having 1 to 8 carbon atoms. Specifically, methyl, ethyl, and tert-butyl groups are more preferred. Examples of the aromatic hydrocarbon group include a phenyl group, a halogenophenyl group, and a nitrophenyl group. R 6 represents an alkyl group, a halogenoalkyl group, or an aromatic hydrocarbon group. Examples of alkyl groups include linear or branched alkyl groups having 1 to 8 carbon atoms. Specifically, methyl groups, ethyl groups, and the like are more preferred. Examples of halogenoalkyl groups include fluoroalkyl groups. Specifically, a trifluoromethyl group and the like are included. Examples of aromatic hydrocarbon groups include alkylphenyl groups and the like. Specifically, a p-toluene group is included. In (Formula 4), the hydroxyl group has been substituted with a leaving group in order to carry out a nucleophilic substitution reaction in a subsequent reaction. Representative leaving groups are listed here, but the leaving group may be converted to another leaving group such as a halogen.

[0030] Each step in the above reaction scheme is explained below. Step (1) is a step in which compound (2) and compound (3) are reacted to obtain compound (4). This step is a step in which the hydroxy group of compound (2) is sulfonylated. Compound (3) is a sulfonylating agent, and a sulfonyl halide compound such as tosyl chloride, mesyl chloride, or trifluoromethylsulfonyl chloride is preferably used. This reaction is preferably carried out in the presence of a base. Examples of the base that can be used include tertiary amines such as triethylamine and 4-dimethylaminopyridine, and inorganic bases such as sodium hydroxide, potassium hydroxide, and sodium bicarbonate. The reaction can be carried out in a solvent at a temperature of 0°C to 100°C for approximately 1 hour to 40 hours. Examples of solvents that can be used include commonly used solvents such as halogenated hydrocarbons such as dichloromethane, aromatic hydrocarbons such as benzene and toluene, ethers, and acetonitrile.

[0031] Step (2) is a step in which compound (4) is hydrolyzed to obtain compound (5). A typical hydrolysis reaction can be used for this hydrolysis reaction, and for example, an acid hydrolysis reaction using an acid such as hydrochloric acid, or a base hydrolysis reaction using sodium hydroxide, triethylammonium hydroxide, or the like is preferred. For example, in the hydrolysis reaction using hydrochloric acid, a small amount of hydrochloric acid can be added and the reaction can be carried out at 0°C to 100°C for several minutes to 5 hours.

[0032] Step (3) is a step in which compound (5) is reacted with compound (6) to obtain compound (7). This step is a reaction in which compound (6) is bonded to compound (5) to cationize it. This reaction can be carried out by stirring in a solvent at a temperature of about room temperature to about 200°C for about 1 hour to 20 hours. As the solvent, general-purpose solvents such as halogenated hydrocarbons such as dichloromethane, aromatic hydrocarbons such as benzene and toluene, ethers, and acetonitrile can be used.

[0033] In step (4), compound (7) is zwitterionized. An anion exchange resin having a quaternary ammonium group can be added to neutralize the compound.

[0034] The zwitterion represented by general formula (1) is liquid at room temperature and stable at temperatures above 240°C without decomposition. Furthermore, it has been found that the zwitterion has low toxicity and a high ability to dissolve cellulose, a major component of plant cell walls, even at high concentrations. Therefore, the zwitterion of the present invention is useful as a plant cell wall dissolving agent composition or a cellulose dissolving agent composition.

[0035] When the zwitterion of the present invention is used as a plant cell wall lysing composition or a cellulose lysing composition, a liquid containing only the zwitterion of the present invention may be used as is, or may be used in combination with other components. That is, the plant cell wall lysing composition or cellulose lysing composition of the present invention may contain 5% to 100% by mass of the zwitterion of the present invention. Other components that can be contained in the plant cell wall lysing composition or cellulose lysing composition include other components that dissolve cellulose, such as ionic liquids and LiCl / dimethylacetamide. Furthermore, organic solvents that do not dissolve cellulose alone can dissolve cellulose when mixed with them, such as water, methanol, and dimethyl sulfoxide. Various medium components can also be added.

[0036] To dissolve plant cell walls or cellulose using the plant cell wall dissolving composition or cellulose dissolving composition of the present invention, a composition containing the zwitterion of the present invention may be contacted with a plant or cellulose-containing plant. Specifically, the plant may be added to the composition containing the zwitterion of the present invention and dissolved at a temperature between room temperature and 240°C. Examples of plants that can be used as plant biomass raw materials include wood chips, various plants, various plant wastes, agricultural residues, thinned wood, waste paper, disposable chopsticks, paper cups, wood, and waste materials. By dissolving such materials with the plant cell wall dissolving composition of the present invention and subjecting them to the necessary treatment, they are expected to be used as raw materials for, for example, ethanol, biodiesel, and other industrial raw materials or useful substances. For example, when producing ethanol from plant biomass, the plant biomass is pretreated with the plant cell wall dissolving composition of the present invention to dissolve cellulose and other materials, and then the cellulose is enzymatically hydrolyzed to glucose according to a conventional method, followed by microbial fermentation to obtain ethanol. Generally, highly polar and water-soluble substances such as plant cell wall lysing agents are difficult to remove, and if they remain, there is a concern that they may be toxic when enzymes or microorganisms are used in subsequent treatments. The plant cell lysing composition of the present invention has low toxicity to enzymes and microorganisms, making it possible to expand the options for subsequent treatments.

[0037] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. (Nuclear Magnetic Resonance) 1H-NMR was measured using a JEOL ECA400 (external magnetic field 400 MHz). (Fast Atom Bombardment-Mass Spectrometry (FAB-MS)) Fast atom bombardment-mass spectrometry was performed using a JEOL JMS-700 double-focusing mass spectrometer owned by the Kanazawa University Instrumental Analysis Research Facility. (Sodium Concentration Meter) Manufacturer: Daiki Rika Kogyo Co., Ltd. (HORIBA Compact Sodium Ion Meter) Experimental Method: Two-point calibration was performed according to the instructions before use. The aqueous layer after separation was not concentrated, but was collected as is and dropped into the concentration meter for measurement. (Viscosity Measurement) The viscometer used was a Brookfield LVDV2TCP with a CPE52 spindle, or a Brookfield RVDV2T with a CPE52 spindle. (DSC-60A Plus) Manufacturer: Shimadzu Corporation Experimental method: Under a N2 atmosphere, liquid nitrogen was used for cooling. Starting from 25°C, the temperature was raised at a rate of 10°C / min to 20°C below the thermal decomposition point, and then the cycle of "cooling to -100°C at a rate of -10°C / min → heating to 20°C below the thermal decomposition point at a rate of 10°C / min" was repeated twice (hold time of 5 minutes each) before cooling to 25°C. (TG-DTA) Manufacturer: Shimadzu Corporation, DTG-60A Experimental method: Under a N2 atmosphere, the temperature was raised to 500°C at a rate of 10°C / min starting from room temperature. The thermal decomposition point was evaluated at the intersection of the tangents at steady state and decomposition.

[0038] Synthesis Example 1 (C1imC2OE3C(R 1 = CH3, A = imidazolium cation, R 2 = CH2CH2, R 3 =CH2CH2, n=3, B=-COO -) [Raw Materials] Benzenesulfonyl chloride, p-toluenesulfonyl chloride, 1-methylimidazole, sodium hydroxide, and diethyl ether were purchased from Tokyo Chemical Industry Co., Ltd. Toluene, dichloromethane, MeOH, chloroform-d1, 99.8 atom% D with 0.03 vol% TMS were purchased from Kanto Chemical Co., Inc. Tetrahydrofuran with stabilizer and hydrochloric acid were purchased from FUJIFILM Wako Pure Chemical Corporation. Aluminum oxide (active, basic, Brockmann 1) was purchased from Sigma-Aldrich. Amberlite IRN-78, ion exchange resin, nuclear grade, was purchased from Alfa Aesar. tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was purchased from Accela ChemBio.

[0039]

[0040] (1) Synthesis of p-toluenesulfonyl PEG4 tert-butyl ester (1a) 4.9 g of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was placed in a 50 mL recovery flask and dissolved in 30 mL of dichloromethane (DCM). The recovery flask was then cooled on ice, and 2.45 g of NaOH was added to the recovery flask to make a 3.5 molar equivalent of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate solution, followed by stirring under ice cooling. Furthermore, 4.4 g of p-toluenesulfonyl chloride was added dropwise to the stirred eggplant flask while cooling with ice so that the ratio was 1.3 equiv. relative to tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate. After the entire amount was added dropwise, the mixture was stirred at room temperature for 28 hours to allow the reaction to proceed. After stirring for 28 hours, solid impurities were removed using filter paper (5C, ADVANTEC). The reaction solution containing the filtered product was placed in a separatory funnel and washed with 60 mL of DCM. Water was then added, and the pH and sodium concentration of the aqueous layer after separation were measured. Separation was continued until the pH reached 7 and the measured sodium concentration reached 0 ppm. After separation, the DCM layer was dried under reduced pressure to obtain the product. The structure of the product was confirmed by 1H NMR, and the product was used as the next raw material without purification.

[0041] (2) Synthesis of p-toluenesulfonyl PEG4 acid (2a) The synthesized p-toluenesulfonyl PEG4 tert-butyl ester was placed in a 200 mL recovery flask, and 45 g of 36% HCl aqueous solution was added to the p-toluenesulfonyl PEG4 tert-butyl ester to give a 25% equiv. solution. The mixture was stirred at room temperature for 3 hours to allow the reaction to proceed. After stirring for 3 hours, the reaction solution containing the product was placed in a separatory funnel and washed with 120 mL of DCM. Water was then added, and the mixture was separated until the pH of the aqueous layer reached 7. After separation, the DCM layer was dried under reduced pressure to obtain the product. The structure of the product was confirmed by 1H NMR, and the product was used as the next raw material without purification.

[0042] (3) Synthesis of imidazolium p-toluenesulfonyl PEG4 acid (3a) The synthesized p-toluenesulfonyl PEG4 acid was placed in a 200 mL recovery flask, and 20 mL of tetrahydrofuran purified with aluminum oxide (active, basic, Brockmann 1) was added and dissolved. The recovery flask was then ice-cooled, and 1.77 g of 1-methylimidazole was added. After ice-cooling and stirring, the mixture was refluxed at 70 °C for 45 hours using a reflux condenser to allow the reaction to proceed. After refluxing for 45 hours, the reaction solution was dried under reduced pressure, and the resulting product was washed with diethyl ether (40 mL, 4 h, 3 times) in a 200 mL recovery flask. After washing, the product was obtained by drying under reduced pressure. The structure of the product was confirmed by 1H NMR, and the product was used as the raw material for the next step without purification.

[0043] (4) Synthesis of imidazolium hydroxide (4a) and C1imCOE3C. The synthesized imidazolium p-toluenesulfonate was dissolved in 600 mL of HO / MeOH (1 / 2: w / w) solvent and transferred to a 1 L bottle. Then, 35 mL of anion exchange resin (Amberlite IRN-78, exchange capacity 1.1 eq / L) was added, and the mixture was stirred at room temperature for 10 days to produce imidazolium hydroxide. After anion exchange, the anion exchange resin was removed using filter paper (5C, ADVANTEC), and the reaction solution was transferred to a 20 mL recovery flask. The resulting reaction solution was concentrated, and the neutralization reaction and the C1imCOE3C production reaction were allowed to proceed. Then, diethyl ether was added to the 20 mL recovery flask containing the product and washed (20 mL, 1 day, 3 times). After washing, the product was dried under reduced pressure to obtain an oily product (purity 98%). The yield based on tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was 56%.

[0044] 11H NMR (400 MHz; CDCl3; Me4Si) δ = 2.424 (2H, t, J = 4.0 Hz, CH2COO), 3.538 - 3.644 (8H, m, OCH2CH2OCH2CH2OCH2CH2COO), 3.790 (2H, t, J = 11.6 Hz, NCH2CH2OCH2), 3.919 (2H, t, J = 9.6 Hz, NCH2CH2OCH2), 3.980 (3H, s, CH3N), 4.499 (2H, t, J = 9.6 Hz, NCH2CH2O), 7.238 and 7.243 (1H, m, NCHCHN), 10.465 (1H, s, NCHN). Mass spectrometry with fast atom bombardment ionization: in positive mode, m / z = 287.1610 (M+H + , found) and 287.1607 (M+H + , calculated); and in negative mode, m / z = 285.1452 (M−H + , found) and 285.1450 (M−H + )(calculated).

[0045] Synthesis Example 2 (OE2imC2OE3C(R 1 = H3C(OCH2CH2)2, A = imidazolium cation, R 2 = CH2CH2, R 3 = CH2CH2, n = 3, B = -COO -) [Raw Materials] Benzenesulfonyl chloride, p-toluenesulfonyl chloride, imidazole, diethylene glycol monomethyl ether, sodium hydroxide, and diethyl ether were purchased from Tokyo Chemical Industry Co., Ltd. Toluene, dichloromethane, MeOH, chloroform-d1, 99.8 atom% D with 0.03 vol% TMS were purchased from Kanto Chemical Co., Inc. Tetrahydrofuran with stabilizer and hydrochloric acid were purchased from FUJIFILM Wako Pure Chemical Corporation. Aluminum oxide (active, basic, Brockmann 1) was purchased from Sigma-Aldrich. Amberlite IRN-78, ion exchange resin, nuclear grade was purchased from Alfa Aesar. tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was purchased from Angene International Limited.

[0046]

[0047] (1) Synthesis of p-toluenesulfonyl PEG4 tert-butyl ester (1a) 3.72 g of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was placed in a 50 mL recovery flask and dissolved in 10 mL of DCM. The recovery flask was then cooled on ice, and 3.38 g of NaOH was added to the recovery flask to a molar equivalent of 6.2 equivalents relative to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate, followed by stirring under ice cooling. Furthermore, 1.3 equivalents relative to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was added. 3.3 g of p-toluenesulfonyl chloride was added dropwise to a stirring recovery flask under ice cooling so that the temperature reached 100°C. After the entire amount was added dropwise, the mixture was stirred at room temperature for 17 hours to allow the reaction to proceed. After stirring for 17 hours, solid impurities were removed using filter paper (5C, ADVANTEC). The reaction solution containing the filtered product was placed in a separatory funnel and washed with 60 mL of DCM. Water was then added, and the pH and sodium concentration of the aqueous layer after separation were measured. Separation was continued until the pH reached 6 and the measured sodium concentration reached 0 ppm. After separation, the DCM layer was dried under reduced pressure to obtain the product. The structure of the product was confirmed by 1H NMR and used in the next reaction.

[0048] (2) Synthesis of p-toluenesulfonyl PEG4 acid (2a) The synthesized p-toluenesulfonyl PEG4 tert-butyl ester was placed in a 200 mL recovery flask, and 34.4 g of 36% HCl aqueous solution was added so that the concentration was 25 equiv. relative to the p-toluenesulfonyl PEG4 tert-butyl ester. The mixture was stirred at room temperature for 3 hours to allow the reaction to proceed. After stirring for 3 hours, the reaction solution containing the product was placed in a separatory funnel and washed with 50 mL of DCM. Water was then added, and the mixture was separated until the pH of the aqueous layer after separation reached 7. After separation, the DCM layer was dried under reduced pressure to obtain the product. The structure of the product was confirmed by 1H NMR and used in the next reaction.

[0049] Synthesis of OE2im: This was prepared with reference to Cellulose, 29, 3017-3024. To synthesize diethylene glycol monomethyl benzenesulfonate, sodium hydroxide (2.5 equivalents, 55 g, 1.38 mol) and an equal amount of water (55 g) were mixed, and the resulting solution was added to a solution of diethylene glycol monomethyl ether (1 equivalent, 60 g, 0.5 mol) in toluene (1000 mL), followed by the addition of diethylene glycol monomethyl ether. A catalytic amount of benzyltrimethylammonium hydroxide (10 mL) was added, and the mixture was stirred in an ice bath. Then, benzenesulfonyl chloride (97 g, 0.6 mol) was added dropwise with stirring, and the mixture was refluxed at 70°C for 6 hours. After evaporating the toluene, the resulting solution was dissolved in dichloromethane, washed once with water (3000 mL), and dried over sodium sulfate to obtain the product. To synthesize 1-(2-(2-methoxyethoxy)ethyl)imidazole (OE2im), an aqueous solution of sodium hydroxide was prepared using sodium hydroxide (2.5 equivalents, 56.4 g, 1.4 mol) and an equal volume of water (57 g). This base was added to a solution of imidazole (1 equivalent, 32 g, 0.5 mol) in toluene (1,000 mL), followed by the addition of a catalytic amount of benzyltrimethylammonium hydroxide (10 mL). Diethylene glycol monomethylbenzenesulfonate (123 g, 0.5 mol) was then slowly added while cooling in an ice bath, and the mixture was heated at 70°C for 6 hours to obtain a colorless viscous liquid. After evaporating the toluene, the mixture was distilled under reduced pressure (1 Pa) at 160°C to obtain OE2im (yield: 92%). The structure of the product was confirmed by 1H NMR and used in the subsequent reaction.

[0050] (3) Synthesis of oligoether imidazolium p-toluenesulfonyl PEG4 acid (3b) The synthesized p-toluenesulfonyl PEG4 acid was placed in a 200 mL recovery flask, and 40 mL of toluene was added to dissolve the mixture. Then, 2.3 g of OE2im was added and stirred, followed by refluxing at 80°C for 27 hours using a reflux condenser. After refluxing for 27 hours, the reaction solution was dried under reduced pressure, and the resulting product was washed with diethyl ether (50 mL, 1 day, 3 times) in a 200 mL recovery flask. After washing, the product was dried under reduced pressure to obtain the product. The structure of the product was confirmed by 1H NMR and used in the next reaction.

[0051] (4) Synthesis of oligoether imidazolium hydroxide (4b) and OE2imC2OE3C. The synthesized imidazolium p-toluenesulfonate was dissolved in 400 mL of HO / MeOH (1 / 3: w / w) solvent and transferred to a 1 L bottle. Then, 27 mL of excess anion exchange resin (Amberlite IRN-78, exchange capacity 1.1 eq / L) was added and stirred at room temperature for 10 days to produce oligoether imidazolium hydroxide. Finally, OE2imC2OE3C was synthesized. After anion exchange, the anion exchange resin was removed using filter paper (5C, ADVANTEC), and the reaction solution was transferred to a 50 mL recovery flask. The resulting reaction solution was concentrated, and the neutralization reaction and the OE2imC2OE3C production reaction were allowed to proceed. Then, diethyl ether was added to the 50 mL recovery flask containing the product and washed (30 mL, 1 day, 3 times). After washing, the product was dried under reduced pressure to obtain a liquid product. The purity was 98%, and the yield was approximately 50% based on tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate.

[0052] 1 ​H NMR (400 MHz; CDCl3; Me4Si) δ = 2.428 (2H, t, J = 10.8 Hz, CH2COO), 3.354 (3H, s, CH3OCH2CH2OCH2CH2N), 3.498 - 3.654 (6H, m, CH3OCH2CH2OCH2CH2N and NCH2CH2OCH2CH2OCH2CH2COO), 3.782 (2H, t, J = 11.6 Hz, CH3OCH2CH2OCH2CH2N), 3.875 (2H, t, J = 9.6 Hz, NCH2CH2OCH2CH2OCH2CH2COO), 4.474 (2H, t, J = 9.6 Hz, NCH2CH2OCH2CH2OCH2CH2COO), 4.563 (2H, t, J = 9.2 Hz, NCH2CH2OCH2CH2OCH2CH2COO), 7.242 and 7.395 (1H, m, NCHCHN), 10.659 (1H, s, NCHN). Mass spectrometry with fast atom bombardment ionization: in positive mode m / z = 375.2129 (M + H + , found) and 375.2131 (calculated); and in negative mode, m / z = 373.1977 (M - H + found) and 373.1975 (calculated).

[0053] Synthesis Example 3 (C2imOE3C(R 1 = C2H5, A = imidazolium cation, R 2 = CH2CH2, R 3 = CH2CH2, n = 3, B = -COO -) [Raw Materials] tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was purchased from Angene. p-toluenesulfonyl chloride, sodium hydroxide, and diethyl ether were purchased from Tokyo Chemical Industry Co., Ltd. 1-Ethylimidazole, toluene, dichloromethane, methanol, chloroform-d1, 99.8 atom% D with 0.03 vol% TMS, and dimethyl sulfoxide-d6, 99.9 atom% D with 0.03 vol% TMS were purchased from Kanto Chemical Co., Inc. Hydrochloric acid was purchased from FUJIFILM Wako Pure Chemical Corporation. Amberlite IRN-78, ion exchange resin, nuclear grade, was purchased from Alfa Aesar.

[0054]

[0055] (1) Synthesis of p-toluenesulfonyl PEG4 tert-butyl ester (1a) 3.7 g of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was placed in a 50 mL recovery flask and dissolved in 40 mL of dichloromethane (DCM). Then, 3.8 g of NaOH (6 equiv. (molar equivalent) relative to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate) was added. The recovery flask was then cooled on ice, and 1.5 equiv. of NaOH relative to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was added. 5.0 g of p-toluenesulfonyl chloride was added dropwise little by little. After the entire amount was added dropwise, the mixture was stirred at room temperature for 34 hours to react, and solid impurities were removed using filter paper (5C, ADVANTEC). The reaction solution containing the filtered product was placed in a separatory funnel. Water was then added, and the sodium concentration of the aqueous layer was measured using a sodium concentration meter. Separation was continued until the measured sodium concentration reached 0 ppm. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 tert-butyl ester (1a) (properties: liquid).

[0056] (2) Synthesis of p-toluenesulfonyl PEG4 acid (2a) p-toluenesulfonyl PEG4 tert-butyl ester was placed in a 200 mL recovery flask, and 9.0 g of 36% aqueous HCl was added in excess of the p-toluenesulfonyl PEG4 tert-butyl ester. The mixture was stirred at room temperature for 3 hours to allow the reaction to proceed. The reaction solution containing the product was dissolved in DCM and poured into a separatory funnel. Water was then added, the pH was measured using pH test paper, and separation was performed until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure and transferred to a 300 mL recovery flask. 100 mL of excess water was added, and the mixture was stirred at 60°C for 1 hour to decompose unreacted p-toluenesulfonyl chloride. The reaction solution was dissolved in DCM, placed in a separatory funnel, and water was added. The pH was measured using pH test paper, and separation was carried out until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 acid (2a) (state: liquid, yield: 20% based on the initial amount of raw materials charged).

[0057] (3) Synthesis of ethylimidazolium p-toluenesulfonyl PEG4 acid (3a) was placed in a 50 mL recovery flask and dissolved in 10 mL of toluene. The recovery flask was then cooled on ice, and 0.27 g of 1-ethylimidazole (1.05 equiv. relative to the p-toluenesulfonyl PEG4 acid) was added dropwise in small amounts. After the entire amount was added dropwise, the mixture was reacted at 80°C for 20 hours using a reflux condenser, resulting in layer separation into an upper layer containing unreacted material and a lower layer containing the product. The upper layer was discarded by decantation, and the lower layer containing the product was washed with diethyl ether (20 mL, 1 h, 3 times). After washing, the product was dried under reduced pressure to obtain ethylimidazolium p-toluenesulfonate (3a) (properties: liquid).

[0058] (4) Synthesis of ethylimidazolium hydroxide (4a) and C2imOE3C Ethylimidazolium p-toluenesulfonate was placed in a 110 mL vial and dissolved in 70 mL of methanol. Furthermore, 9 mL of strong anion exchange resin Amberlite IRN-78 (exchange capacity 1.1 eq. / L) was added and stirred at room temperature for 5 days to produce ethylimidazolium hydroxide (4a). The reaction solution was concentrated into a 50 mL flask, and the neutralization reaction was allowed to proceed. Then, diethyl ether was added to the recovery flask containing the product and washed (20 mL, 30 min, 3 times). After washing, the product was dried under reduced pressure to obtain C2imOE3C (properties: liquid).

[0059] C2imOE3C: 1 H NMR (400MHz; DMSO; Me4Si) δ = 1.380 (3H, t, J = 7.4Hz, NCH2CH3), 1.970 (2H, t, J = 7. 0Hz, CH2COO), 3.325-3.497 (10H, m, NCH2H2OCH2CH2OCH2CH2OCH2CH2COO), 3.750 and 4.320 (2H, t, J = both 5.0 Hz, NCH2CH2OCH2), 4.199 (2H, q, NCH2CH3), 7.747 and 7.826 (1H, m, NCHCHN), 9.613 (1H, s, NCHN).

[0060] Synthesis Example 4 (AimOE3C(R 1 = -CH2-CH=CH2, A = imidazolium cation, R 2 = CH2CH2, R 3 =CH2CH2, n=3, B=-COO -) [Raw Materials] tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was purchased from Angene. p-toluenesulfonyl chloride, sodium hydroxide, and diethyl ether were purchased from Tokyo Chemical Industry Co., Ltd. 1-allylimidazole, toluene, dichloromethane, methanol, chloroform-d1, 99.8 atom% D with 0.03 vol% TMS, and dimethyl sulfoxide-d6, 99.9 atom% D with 0.03 vol% TMS were purchased from Kanto Chemical Co., Inc. Hydrochloric acid was purchased from FUJIFILM Wako Pure Chemical Corporation. Amberlite IRN-78, ion exchange resin, nuclear grade, was purchased from Alfa Aesar.

[0061]

[0062] (1) Synthesis of p-toluenesulfonyl PEG4 tert-butyl ester (1a) 3.0 g of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was placed in a 50 mL recovery flask and dissolved in 30 mL of DCM. Then, 1.6 g of NaOH (3.7 equiv. / molar equivalent) was added to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate. The recovery flask was then cooled on ice, and 1.3 equiv. / mol. of NaOH was added to the recovery flask. 2.6 g of p-toluenesulfonyl chloride was added dropwise little by little. After the entire amount was added dropwise, the mixture was stirred at room temperature for 24 hours to react, and solid impurities were removed using filter paper (5C, ADVANTEC). The reaction solution containing the filtered product was placed in a separatory funnel. Water was then added, and the sodium concentration of the aqueous layer was measured using a sodium concentration meter. Separation was continued until the measured sodium concentration reached 0 ppm. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 tert-butyl ester (1a) (properties: liquid).

[0063] (2) Synthesis of p-toluenesulfonyl PEG4 acid (2a) p-toluenesulfonyl PEG4 tert-butyl ester was placed in a 200 mL recovery flask, and 9.0 g of 36% aqueous HCl was added in excess of the p-toluenesulfonyl PEG4 tert-butyl ester. The mixture was stirred at room temperature for 3 hours to allow the reaction to proceed. The reaction solution containing the product was dissolved in DCM and poured into a separatory funnel. Water was then added, the pH was measured using pH test paper, and separation was performed until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure and transferred to a 300 mL recovery flask. 100 mL of excess water was added, and the mixture was stirred at 60°C for 1 hour to decompose unreacted p-toluenesulfonyl chloride. The reaction solution was dissolved in DCM, placed in a separatory funnel, and water was added. The pH was measured using pH test paper, and separation was carried out until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 acid (2a) (state: liquid, yield: 39% based on the initial amount of raw materials charged).

[0064] (3) Synthesis of allylimidazolium p-toluenesulfonate (3b) 1.16 g of p-toluenesulfonyl PEG4 acid was placed in a 50 mL recovery flask, and 10 mL of toluene was added to dissolve the mixture. The recovery flask was then cooled on ice, and 0.36 g of 1-allylimidazole (1.1 equiv. relative to the p-toluenesulfonyl PEG4 acid) was added dropwise little by little. After the entire amount was added dropwise, the mixture was reacted at 80°C for 21 hours using a reflux condenser, resulting in layer separation into an upper layer containing unreacted material and a lower layer containing the product. The upper layer was discarded by decantation, and the lower layer containing the product was washed with diethyl ether (20 mL, 1 h, 3 times). After washing, it was dried under reduced pressure to obtain allylimidazolium p-toluenesulfonate (3b) (properties: liquid).

[0065] (4) Synthesis of allylimidazolium hydroxide (4b) and AimOE3C. Allylimidazolium p-toluenesulfonate was placed in a 110 mL vial and dissolved in 80 mL of methanol. Furthermore, 11 mL of strong anion exchange resin Amberlite IRN-78 (exchange capacity 1.1 eq. / L) was added and stirred at room temperature for 6 days to produce allylimidazolium hydroxide (4b). The reaction solution was concentrated into a 50 mL flask, and the neutralization reaction was allowed to proceed. Then, diethyl ether was added to the recovery flask containing the product and washed (20 mL, 30 min, 3 times). After washing, the mixture was dried under reduced pressure to obtain AimOE3C (properties: liquid).

[0066] AimOE3C: 1 H NMR (400MHz; DMSO; Me4Si) δ = 2.009 (3H, t, J = 7.0Hz, CH2COO), 3.390-3.548 (10H, m, NCH2CH2OCH2CH2OCH2CH2OCH2CH2COO), 3.797 and 4.380 (2H, t, J=5.0 and 4.8Hz, NCH2CH2OCH2), 4.915 (2H, d, NCH2CHCH2), 5.249-5.357 (2H, m, NCH2CHCH2), 6.016-6.114 (1H, m, NCH2CHCH2), 7.775 and 7.823 (1H, m, NCHCHN), 9.656 (1H, s, NCHN).

[0067] Synthesis Example 5 (VimOE3C(R 1 = -CH = CH2, A = imidazolium cation, R 2 = CH2CH2, R 3 =CH2CH2, n=3, B=-COO -) Synthesis of Precursor—Vinylimidazolium p-toluenesulfonate) [Raw Materials] tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was purchased from Angene. p-toluenesulfonyl chloride, sodium hydroxide, and diethyl ether were purchased from Tokyo Chemical Industry Co., Ltd. 1-Vinylimidazole, toluene, dichloromethane, methanol, chloroform-d1, 99.8 atom% D with 0.03 vol% TMS, and dimethyl sulfoxide-d6, 99.9 atom% D with 0.03 vol% TMS were purchased from Kanto Chemical Co., Inc. Hydrochloric acid was purchased from FUJIFILM Wako Pure Chemical Corporation. Amberlite IRN-78, ion exchange resin, nuclear grade, was purchased from Alfa Aesar.

[0068]

[0069] (1) Synthesis of p-toluenesulfonyl PEG4 tert-butyl ester (1a) 3.0 g of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate was placed in a 50 mL recovery flask and dissolved in 30 mL of DCM. Then, 1.6 g of NaOH (3.7 equiv. / molar equivalent) was added to the tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate. The recovery flask was then cooled on ice, and 1.3 equiv. / mol. of NaOH was added to the recovery flask. 2.6 g of p-toluenesulfonyl chloride was added dropwise little by little. After the entire amount was added dropwise, the mixture was stirred at room temperature for 24 hours to react, and solid impurities were removed using filter paper (5C, ADVANTEC). The reaction solution containing the filtered product was placed in a separatory funnel. Water was then added, and the sodium concentration of the aqueous layer was measured using a sodium concentration meter. Separation was continued until the measured sodium concentration reached 0 ppm. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 tert-butyl ester (1a) (properties: liquid).

[0070] (2) Synthesis of p-toluenesulfonyl PEG4 acid (2a) p-toluenesulfonyl PEG4 tert-butyl ester was placed in a 200 mL recovery flask, and 9.0 g of 36% aqueous HCl was added in excess of the p-toluenesulfonyl PEG4 tert-butyl ester. The mixture was stirred at room temperature for 3 hours to allow the reaction to proceed. The reaction solution containing the product was dissolved in DCM and poured into a separatory funnel. Water was then added, the pH was measured using pH test paper, and separation was performed until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure and transferred to a 300 mL recovery flask. 100 mL of excess water was added, and the mixture was stirred at 60°C for 1 hour to decompose unreacted p-toluenesulfonyl chloride. The reaction solution was dissolved in DCM, placed in a separatory funnel, and water was added. The pH was measured using pH test paper, and separation was carried out until the pH of the aqueous layer reached 6. After separation, the DCM layer was dried under reduced pressure to obtain p-toluenesulfonyl PEG4 acid (2a) (state: liquid, yield: 39% based on the initial amount of raw materials charged).

[0071] (3) Synthesis of vinylimidazolium p-toluenesulfonate (3c) 0.5 g of p-toluenesulfonyl PEG4 acid was placed in a 50 mL recovery flask, and 10 mL of toluene was added to dissolve the mixture. The recovery flask was then cooled on ice, and 0.15 g of 1-vinylimidazole (1.2 equiv. relative to the p-toluenesulfonyl PEG4 acid) was added dropwise little by little. After the entire amount was added dropwise, the mixture was reacted at 80°C for 17 hours using a reflux condenser, resulting in layer separation into an upper layer containing unreacted material and a lower layer containing the product. The upper layer was discarded by decantation, and the lower layer containing the product was washed with diethyl ether (20 mL, 1 h, 3 times). After washing, the product was dried under reduced pressure to obtain vinylimidazolium p-toluenesulfonate (3b) (state: liquid).

[0072] Vinylimidazolium p-toluenesulfonate: 1H NMR (400MHz; DMSO; Me4Si) δ = 2.286 (3H, s, CHCCH3), 2.430 (2H, t, J = 6.4, CH2 COOH), 3.465-3.631 (10H, m, NCH2CH2OCH2CH2OCH2CH2OCH2CH2COOH), 3.798 and 4.379 (2H, t, J = both 5.0Hz, NCH2CH2OCH2), 5.431 (1H, dd, J = 2.8 and 2.4Hz, NCHCH2), 5.963 (1H, dd, J=both2.4Hz, NCHCH2), 7.121 and 7.490 (2H, d, J = both 7.6Hz, SO2CHCHCCH3CHCH), 7.274-7.350 (1H, m, NCHCH2), 7.880 and 8.199 (1H, m, NCHCHN), 9.408 (1H, s, NCHN), 12.181 (1H, s, CH2COOH).

[0073] Synthesis Example 6 (C1imC3P(R 1 = CH3, A = imidazolium cation, R 2 =(CH2)3, n=0, B=-P(=O)(O2H5)O - ) synthesis

[0074]

[0075] C1imC3P was synthesized using 1-methylimidazole and diethyl(3-bromopropyl)phosphate. The raw materials were reacted at 40°C for 48 hours using acetone as the solvent, and the C1imC3P intermediate was synthesized. The product was then washed with diethyl ether and subjected to ion exchange.

[0076] Synthesis Example 7 (C1imC2P(R 1 = CH3, A = imidazolium cation, R 2 =(CH2)2, n=0, B=-OP(=O)(O2H5)O - ) synthesis

[0077]

[0078] It was synthesized using 1-methylimidazole and 2-ethoxy-2-oxo-1,3,2-dioxophosphorane, a cyclic phosphoric acid, as raw materials. C1imC2P was synthesized by reacting the raw materials in a 2:1 ratio without solvent at 27°C for 48 hours. The synthesized C1imC2P was diluted with water and mixed and stirred with anion exchange resin (Amberlite IRN78 hydroxide form). The anion exchange resin was removed by filtration, and the water was distilled off under reduced pressure. After washing with an excess amount of diethyl ether, high purity C1imC2P was synthesized. The purity was 1 This was confirmed by the results of H NMR, mass spectrometry, and elemental analysis. Mass spectrometry [M+H] + 233.0695 (measured value), 233.0686 (theoretical value) [M-H] - 235.0847 (measured), 235.0842 (theoretical) Elemental analysis C1imC2P·1.9H2O (measured: C, 35.95; H, 7.06; N, 10.17; theoretical C8H 18.8 N2O 5.9 :C, 35.80; H, 7.06; N, 10.44%) 1 The H NMR chart is shown in Figure 1.

[0079] Test Example 1 C1imC2OE3C(R 1 = CH3, A = imidazolium cation, R 3 =CH2CH2, n=3, B=-COO - ) and OE2imC2OE3C(R 1 = H3C(OCH2CH2)2, A = imidazolium cation, R 3 =CH2CH2, n=3, B=-COO - ) were all liquids at room temperature (25°C). C1imC2OE3C obtained in Synthesis Example 1 was heated at a rate of 10°C / min to measure the temperature at which weight loss occurred (thermal decomposition temperature). As a result, this compound thermally decomposed at approximately 249°C and remained stable up to 249°C.

[0080] Test Example 2 Differential scanning calorimetry was performed on C1imC2OE3C obtained in Synthesis Example 1. As a result, it was found that this compound did not change up to around 250°C and remained in a liquid state from room temperature to around 250°C.

[0081] Test Example 3 The viscosity at 80°C was measured for C1imC2OE3C obtained in Synthesis Example 1 and OE2imC2OE3C obtained in Synthesis Example 2. The viscometer used was a Brookfield LVDV2TCP with a CPE52 spindle. The device was heated to 80°C by passing heated water through it, and the viscosity of the sample was measured.

[0082] Test Example 4: C1imC2OE3C obtained in Synthesis Example 1, OE2imC2OE3C obtained in Synthesis Example 2, and OE2imC3C (R) as a comparative example 1 =H3C(OCH2CH2)2, A = imidazolium cation, B = -COO - The cellulose-decomposing ability of a compound (where n=0, n=0 (a compound having no oxyalkylene structure between the cation and anion moieties, a compound described in Non-Patent Document 2)) was measured. Cellulose-decomposing ability was measured by adding cellulose (Avisel) in increasing concentrations starting from 1 wt %, heating and stirring at 120°C for 1 hour. The concentration at which cellulose dissolution could be visually confirmed was measured. The results of Test Examples 3 and 4, as well as the properties of the zwitterions at 25°C, are shown in Table 2.

[0083]

[0084] Table 2 shows that the zwitterions of the present invention are liquid at room temperature, have low viscosity, and can dissolve high concentrations of cellulose, making them useful as plant cell wall dissolving agents.

[0085] Test Example 5: The cellulose dissolving ability of C1imC2P was investigated. Although 100 wt% C1imC2P is liquid at room temperature (25°C), it has a very high viscosity. When heated to 80°C, the stirrer rotated in the C1imC2P, and at 120°C it began to rotate smoothly. Therefore, a cellulose dissolution experiment was conducted at 120°C. Avicel was added in 1 wt% increments, and once dissolution was achieved over one hour, additional Avicel was added in 1 wt% increments. The experiment showed that C1imC2P dissolved 4 wt% of Avicel.

[0086] Test Example 6 (Cytotoxicity of C1imC2P) The toxicity of C1imC2P to yeast was investigated. Kluveromyces marshanus was used as the yeast. C1imC2P was added to liquid media to achieve concentrations of 0 mol / L, 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.5 mol / L, and 1.0 mol / L. Bacteria were inoculated into the medium and cultured at 50°C. The OD was measured using a plate reader after 0, 2, 4, and 6 hours. 600 The OD was measured. 600 indicates the density of the bacterial cells. 600 is a relative parameter when the control is set to 1.00. Relative OD 600 Higher values ​​indicate lower toxicity of the zwitterion. 600 The value was 0.77, which indicated low toxicity.

Claims

1. General formula (1) 【Chemical 1】 (R 1 represents a linear alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or C1-8 linear-alkyl-(OCH 2 CH 2 )m-, and A is the cationic part of the zwitterion, and represents a cation selected from an imidazolium cation, a phosphonium cation, a sulfonium cation, a pyrazolium cation, a pyrrolidinium cation, a morpholinium cation, a cyclopropenium cation, and a piperidinium cation. R 2 represents an alkylene group having 1 to 4 carbon atoms, R 3 represents an alkylene group having 2 to 4 carbon atoms, m represents a number of 1 or 2. n represents a number from 0 to 10. B is -SO 3 - , -COO - , -P=O(OR 4 )O - and -OP=O(OR 5 )O - represents an anion selected from, and R 4 and R 5 are the same or different and are a hydrogen atom or an alkyl group which may have a hetero atom and has 1 to 8 carbon atoms (provided that when n is 0, B is -P=O(OR 4 )O - or -OP=O(OR 5 )O - )) The zwitterion represented by

2. The zwitterion according to Claim 1, wherein A in the general formula (1) is a cation selected from an imidazolium cation, a pyrazolium cation, a pyrrolidinium cation, and a piperidinium cation.

3. The zwitterion according to Claim 1, wherein A in the general formula (1) is an imidazolium cation.

4. R in the general formula (1) 1 is a linear alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or C1-4 alkyl-(OCH 2 CH 2 ), where m represents a number of 1 or 2), the zwitterion according to claim 1

5. The zwitterion according to Claim 1, wherein n in the general formula (1) is a number from 1 to 6.

6. B in the general formula (1) is -COO - The zwitterion according to claim 1, wherein it is

7. In the general formula (1), n is from 0 to 6, and B is -P=O(OR 4 )O - or -OP=O(OR 5 )O - The zwitterion according to claim 1, wherein it is such.

8. A plant cell wall lysing agent composition containing the zwitterion according to any one of Claims 1 to 7.

9. A cellulose lysing agent composition containing the zwitterion according to any one of Claims 1 to 7.

10. A method for lysing the cell wall of a plant, comprising the step of bringing a composition containing the zwitterion according to any one of Claims 1 to 7 into contact with the plant.

11. A method for lysing cellulose in a plant, comprising the step of bringing a composition containing the zwitterion according to any one of Claims 1 to 7 into contact with a cellulose-containing plant.

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