JP2020143250A - Method for producing polysaccharide derivative, and method for producing lignin derivative - Google Patents

Abstract

To provide a method for producing polysaccharide derivative, that is advantageous in terms of environment and cost because it does not require the use of a reagent such as an acid catalyst, does not generate waste, and does not require base.SOLUTION: The method for producing polysaccharide derivative of the present invention is characterized by comprising a step in which a polysaccharide-containing raw material is dissolved in at least one ionic liquid where the cation is an azorium ion and the conjugate acid of the anion has a pKa in vacuum of 1 or more, and is oxidatively reacted with aldehyde.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a polysaccharide derivative and a method for producing a lignin derivative.

Cellulose derivatives such as cellulose acetate are useful as thermoplastic plastic materials. Various methods for producing polysaccharide derivatives such as cellulose derivatives have been studied. As a conventional method for producing a polysaccharide derivative, a classical esterification method is known in which cellulose and an esterifying agent are reacted under intense conditions in the presence of an acid catalyst. This method has a problem that cellulose is decomposed during the reaction and the degree of polymerization is lowered, so that the mechanical strength of the obtained cellulose derivative is lowered.

Further, as a method for producing a polysaccharide derivative, a method for producing a cellulose ester by a condensation reaction between cellulose and an acylating agent such as an acid chloride, an acid anhydride, an active ester, or an inactive ester is also known. For example, in (Non-Patent Document 1), cellulose is dissolved in 1-ethyl-methylimidazolium acetate (EmimOAc) and DMSO to catalytically activate the inert ester isopropenyl acetate (IPA). Discloses a method for producing cellulose acetate to be reacted as an acylating agent. Such a method using an acylating agent such as an inert ester has a problem that waste derived from the activator is generated. Further, in particular, acid chlorides and acid anhydrides generate acids such as hydrochloric acid as waste by the reaction, so it is necessary to add an excessive amount of a base for trapping hydrochloric acid and the like.

As another method for producing a polysaccharide derivative, (Patent Document 1) is characterized in that a polysaccharide, a small sugar or a disaccharide or a corresponding derivative is dissolved in at least one ionic liquid and reacted with keten. , Polysaccharides, oligosaccharides or disaccharides or derivatives thereof are acylated. However, it was insufficient in terms of efficiency and cost.

Lignin is a polymer compound composed of aromatic compounds, and is a main component constituting the cell wall of plants together with polysaccharides (cellulose and hemicellulose). It is obtained as a by-product of the pulp and paper production process or the bioethanol production process, but it is mainly used only as a fuel, and its industrial use is not progressing at present.

Special Table 2009-540075

R. Kakuchi, et al., RSC Adv., 2017,7, 9423-9430 (DOI: 10.1039 / C6RA28659C)

As described above, since the conventional method for producing a polysaccharide derivative uses an acid catalyst, there is a problem that the obtained derivative is partially decomposed and the mechanical strength is lowered. Further, in another method for producing a polysaccharide derivative, waste is generated due to the use of an activator, and it is necessary to add a base separately, which has a large burden on the environment and cost.

Furthermore, conventionally, the industrial use of lignin has not progressed, and therefore, it has been desired to develop a technique for derivatizing lignin and converting it into a useful material.

Therefore, an object of the present invention is to provide a method for producing a polysaccharide derivative, which is advantageous in terms of environment and cost because it does not require the use of a reagent such as an acid catalyst, does not generate waste, and does not require a base. To do.

Another object of the present invention is to provide a method for producing a lignin derivative, which does not require a reagent such as an acid catalyst and has a small burden on the environment and cost.

As a result of diligent research by the present inventors, it was found that the above-mentioned problems can be solved by dissolving a raw material containing a polysaccharide or lignin in a specific ionic liquid and oxidatively reacting with an aldehyde. completed. That is, the gist of the present invention is as follows.

(1) A step of dissolving a raw material containing a polysaccharide in at least one ionic liquid having an azolium ion as a cation and an anionic conjugate acid having a pKa of 1 or more in vacuum and oxidatively reacting with an aldehyde. A method for producing a polysaccharide derivative containing.
(2) The method for producing a polysaccharide derivative according to (1) above, wherein the polysaccharide is cellulose.
(3) The method for producing a polysaccharide derivative according to (1) or (2) above, wherein the reaction is carried out in the presence of oxygen.
(4) The method for producing a polysaccharide derivative according to (1) or (2) above, wherein the aldehyde is an α, β-unsaturated aldehyde and the reaction is carried out without using a separate oxidizing agent.
(5) The method for producing a polysaccharide derivative according to (4) above, wherein the α, β-unsaturated aldehyde is cinnamaldehyde.
(6) Any of the above (1) to (5) for producing at least one of the ionic liquids in which the cation is an azolium ion and the conjugate acid of the anion has a pKa of 1 or more in vacuum during the reaction. The method for producing a polysaccharide derivative according to one.
(7) A step of dissolving a raw material containing lignin in at least one ionic liquid having an azolium ion as a cation and an anionic conjugate acid having a pKa of 1 or more in vacuum and oxidatively reacting with an aldehyde. Method for producing lignin derivative containing.
(8) The method for producing a lignin derivative according to (7) above, wherein the reaction is carried out in the presence of oxygen.
(9) The method for producing a lignin derivative according to (8) above, wherein the aldehyde is an α, β-unsaturated aldehyde and the reaction is carried out without using a separate oxidizing agent.
(10) The method for producing a lignin derivative according to (9) above, wherein the α, β-unsaturated aldehyde is cinnamaldehyde.
(11) Any of the above (7) to (10) for producing at least one of the ionic liquids in which the cation is an azolium ion and the conjugate acid of the anion has a pKa of 1 or more in vacuum during the reaction. The method for producing a lignin derivative according to one.

The method for producing a polysaccharide derivative or a lignin derivative of the present invention does not require the use of an acid catalyst or the like, and thus the mechanical strength of the obtained derivative can be maintained high. Therefore, a useful thermoplastic material can be provided. In addition, it is excellent in terms of environment and cost because no waste is generated due to the reaction and no additional reagent such as a base is required.

Hereinafter, the present invention will be described in detail based on the embodiments.
First, a method for producing a polysaccharide derivative will be described. The method for producing a polysaccharide derivative according to the present embodiment includes a step of dissolving a raw material containing a polysaccharide in a specific ionic liquid and oxidatively reacting with an aldehyde.

As the polysaccharide, various polysaccharides can be applied, and examples thereof include cellulose, hemicellulose, starch, agarose, pectin, chitin, and chitosan. Part of the structure of these polysaccharides may be substituted. For example, a cellulose derivative in which some of the hydroxyl groups of cellulose are esterified can be used as a raw material.

Further, as a raw material containing a polysaccharide, a natural material containing a polysaccharide such as cellulose as a mixture may be used. Specific examples of such materials include bagasse (sugar cane residue), bamboo (bamboo powder), wood such as kenaf, cedar, and eucalyptus, ginnan, and a mixture of two or more of these. In addition, these natural materials can be subjected to various pretreatments such as cutting and drying prior to the reaction of the present embodiment as necessary.

The ionic liquid applicable to this embodiment is at least one in which the cation is an azolium ion and the pKa of the conjugate acid of the anion in vacuum is 1 or more. As the above pKa, a value calculated by Advanced Chemistry Development (ACD / Laboratories) Software, version 11.02 (1994-2011 ACD / Laboratories) can be used. This ionic liquid is used as a solvent for dissolving polysaccharides such as cellulose in the derivatization reaction of the present embodiment, and also functions as a powerful organomolecular catalyst.

The azolium ion is a cation having a hetero 5-membered ring containing a nitrogen atom, and specifically, an imidazolium ion, a triazolium ion, a tetrazolium ion and the like can be applied. Examples of the triazolium ion include 1-methyltriazolium, 1-ethyltriazolium, 1-propyltriazolium, and 1-butyltriazolium ions. Moreover, as a tetrazolium ion, 1-butyl-3-methyltetrazolium ion and the like can be mentioned.

As the azolium ion, the imidazolium ion represented by the following formula (1) is preferably used because it has excellent reaction efficiency and low cost.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立して、アルキル基、アルケニル基、アルコキシアルキル基又は置換もしくは非置換のフェニル基であり、Ｒ^３〜Ｒ^５は、それぞれ独立して、水素、アルケニル基、アルコキシアルキル基又は置換もしくは非置換のフェニル基である。）

(In the formula (1), R ¹ and R ² are independently alkyl groups, alkenyl groups, alkoxyalkyl groups or substituted or unsubstituted phenyl groups, and R ^{3 to} R ⁵ are independent of each other. , Hydrogen, alkenyl group, alkoxyalkyl group or substituted or unsubstituted phenyl group.)

Examples of the alkyl group include a linear or branched alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, a hexyl group and an octyl group. Can be mentioned. A sulfo group may be bonded to the end of these alkyl groups. Examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 2-pentenyl group, 1-hexenyl group and 2-hexenyl group. Examples thereof include a linear or branched alkenyl group having 1 to 20 carbon atoms such as a 1-octenyl group. The alkoxyalkyl group has 2 to 20 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group and a 2-ethoxyethyl group. Examples thereof include linear or branched alkoxyalkyl groups. Further, the substituted or unsubstituted phenyl group includes a hydroxyl group, a halogen atom, a lower alkoxy group, a lower alkenyl group, a methylsulfonyloxy group, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted group. Examples thereof include a phenyl group which may be substituted with 1 or 2 groups selected from a substituted phenyl group, a substituted or unsubstituted phenoxy group and a substituted or unsubstituted pyridyl group.

Further, the anion of the ionic liquid can be applied as long as it can form an ionic liquid having a pKa of 1 or more, preferably 3 to 14 in vacuum of the conjugate acid. Examples include carboxylic acid anions such as formate anion (HCOO ⁻ ), acetate anion (CH ₃ COO ⁻ ), propionic acid ion (CH ₃ CH ₂ CH ₂ COO ⁻ ), and amide-derived anions such as pyridonate anion. Examples thereof include amino acid anion (glutamate anion, etc.), cyanide ion (CN ⁻ ), fluoride ion (F ⁻ ), and the like. These anions may be partially substituted. For example, examples of substituted carboxylic acid anion, 3-phenylpropionic acid anion _{(Ph-CH 2 CH 2 CH} 2 COO -) and the like. Halogen anions other than fluoride ions such as chloride ion (Cl ⁻ ), iodine ion (I ⁻ ), and bromide ion (Br ⁻ ), and strong acid anions such as sulfate anion and phosphate anion are used in the vacuum of the conjugate acid. It is unsuitable because pKa is less than 1.

Examples of ionic liquids preferably used in the production method according to the present embodiment include, but are not limited to, the following compounds.
1-Ethyl-3-methylimidazolium acetate (EmimoAc), 1-butyl-3-methylimidazolium acetate, 1-hexyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium 2-pyridonate (EmimoPy) ), 1-Ethyl-3-methylimidazolium 3-phenylpropionate (EmimPPA) and the like.

In addition to using the above ionic liquid, in the production method according to the present embodiment, at least one ionic liquid in which the cation is an azolium ion and the pKa of the conjugate acid of the anion is 1 or more in vacuum is being reacted. Can also be generated by. For example, imidazolium chlorides (pKa in vacuum less than 1) and a base can be used to generate an active ionic liquid in the reaction system for use. Specific examples of such imidazolium chlorides include 1-butyl-3-methylimidazolium chloride (BmimCl), and the bases are potassium acetate and 1,8-diazabicyclo [5.4.0] undec-. Examples thereof include 7-ene (DBU), sodium acetate, potassium carbonate, potassium fluoride, pyridine, triethylamine, tetraammonium acetate, potassium cyanide and the like.

By dissolving the raw material containing the polysaccharide in the above-mentioned ionic liquid and oxidatively reacting with the aldehyde, the ionic liquid also functions as a catalyst and the derivatization of the polysaccharide proceeds. Here, "oxidatively reacting" means forming an ester bond (-OOCR) between the -OH group of the polysaccharide and the aldehyde (RCHO) while formally oxidizing the aldehyde by using an oxidizing agent or the like. It means to form. As a specific example, the reaction formula for producing a cellulose ester by reacting cellulose and an aldehyde in an ionic liquid using oxygen in the air as an oxidizing agent is shown below.

As the oxidizing agent, in addition to oxygen, various conventionally known substances can be used. Examples include inorganic oxidizing agents such as manganese dioxide and hydrogen peroxide, and organic oxidizing agents such as azobenzene.

The concentration of the raw material containing the polysaccharide in the ionic liquid as the solvent varies depending on the type and molecular weight of the polysaccharide and is not particularly limited. Generally, the weight of the ionic liquid is preferably twice or more the weight of the polysaccharide, and specifically, the concentration of the polysaccharide in the ionic liquid is preferably 5% by weight to 20% by weight.

Further, the ionic liquid can be used as a co-solvent system with an organic solvent. In this case as well, the weight of the ionic liquid is preferably at least twice the weight of the polysaccharide, and within this condition, the amount of the ionic liquid used can be reduced, and the rest is replaced with an organic solvent. It is possible to reduce the production cost of the polysaccharide derivative.

When used as a co-solvent, the organic solvent can be appropriately selected from various organic solvents on the condition that it does not react with the ionic liquid in consideration of solubility in the produced polysaccharide derivative and the like. Specific examples thereof include acetonitrile, tetrahydrofuran (THF), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), 1,3-dioxolane, 1,4-dioxane and the like. Chloroform is often not applicable because it reacts with some ionic liquids such as 1-ethyl-3-methylimidazolium acetate (EmimAc), but it is not excluded from the scope of the present invention. Further, when cellulose butyrate is produced as a polysaccharide derivative, tetrahydrofuran (THF) is preferably used, and when cellulose acetate is produced, dimethyl sulfoxide (DMSO), 1,3-dioxolane and the like are preferably used, but are limited thereto. is not.

As the aldehyde to be reacted with the polysaccharide, it can be appropriately selected and used from various conventionally known aldehydes according to the type of the polysaccharide derivative (esterified polysaccharide) to be produced. Specifically, for example, saturated aliphatic aldehydes such as acetaldehyde, propylaldehyde, hexanal, heptanal, octanal, nonanal, decanal, undecanal, and dodecalal; achlorine, metachlorine, cis-3-hexenal, trans-2-hexenal. , Trans-2-hexenal, cis-4-heptenal, trans-4-heptenal, trans-2-octenal, trans-2-nonenal, cis-6-nonenal, trans-2-decenal, cis-4-decenal, trans Unsaturated aliphatic aldehydes such as -4-decenal, 7-undecenal, 9-undecenal, 10-undecenal; heterocyclic aldehydes such as furfural; aromatic aldehydes such as benzaldehyde, naphthylaldehyde, and anthralaldehyde. It can, but is not limited to. In addition, any one type of aldehyde may be used alone, and 2 or more types may be used.

Examples of the aldehyde preferably used in the production method according to the present embodiment include the following compounds.

In addition, among the above-mentioned aldehydes, α, β-unsaturated aldehydes have a double bond with a high degree of oxidation in the molecule, and the aldehyde itself functions as an oxidizing agent, so an external oxidizing agent such as oxygen is used. Even without it, a polysaccharide derivative (esterified polysaccharide) can be obtained simply by mixing a polysaccharide and an aldehyde in an ionic liquid. As an example, the reaction formula for producing a cellulose ester by reacting cellulose with α, β-unsaturated aldehyde in an ionic liquid without using an oxidizing agent such as oxygen is shown below. In the cellulose ester produced, the double bond in the α, β-unsaturated aldehyde is introduced into the structure in a reduced state.

Examples of the α, β-unsaturated aldehyde preferably used in the production method according to the present embodiment include the following compounds. Among these, cinnamaldehyde is particularly preferably used because it has excellent reactivity and can efficiently obtain a polysaccharide derivative.

Even when the aldehyde is reacted with α, β-unsaturated aldehyde, an external oxidizing agent such as oxygen may be used. When an external oxidant is used, the double bond in the α, β-unsaturated aldehyde is not reduced and can be introduced into the structure of the esterified polysaccharide as it is.

Further, as the aldehyde, a mixture containing the aldehyde may be used as it is. For example, the essential oil can be subjected to the reaction as it is without isolating and purifying the aldehyde component from the essential oil obtained from a natural product. Examples of such essential oils include cinnamon essential oils containing cinnamaldehyde.

The amount of aldehyde to be reacted with the polysaccharide varies depending on the type of polysaccharide and the like, but for example, it is preferable to react 0.3 to 2.0 equivalents with respect to 1 equivalent of the hydroxyl group of the polysaccharide. The reaction conditions may be any condition as long as the ionic liquid functions as a catalyst and the reaction proceeds. For example, a raw material containing a polysaccharide, a mixture of the ionic liquid and an aldehyde are stirred at 25 to 80 ° C. for 1 to 48 hours. The reaction can be carried out. The solution after the reaction can be reprecipitated with a solvent such as methanol and filtered to obtain a predetermined polysaccharide derivative. In addition, the ionic liquid used in the reaction can be recovered and reused.

The produced polysaccharide derivative can be further prepared with various reagents such as aldehyde by a conventional method using a base such as NaOH or an acid catalyst such as sulfuric acid for the purpose of modification or the like, or continuously in the presence of the ionic liquid in the present invention. It can be reacted and converted to another polysaccharide derivative.

Next, as another embodiment, a method for producing a lignin derivative will be described. In this production method, a raw material containing lignin is dissolved in at least one ionic liquid in which the cation is an azolium ion and the conjugate acid of the anion has a pKa of 1 or more in vacuum, and is oxidatively reacted with an aldehyde. It is characterized by including a process. A lignin derivative corresponding to the structure of the aldehyde to be applied can be obtained by carrying out the reaction according to the above-mentioned method for producing a polysaccharide derivative, except that a raw material containing lignin is used instead of the raw material containing a polysaccharide. That is, as shown in the following formula, a derivative in which the hydroxyl group of lignin is esterified with aldehyde is obtained. This esterified product of lignin can be suitably used as a flame retardant or the like. At this time, the lignin molecule includes a hydroxyl group bonded to aromatic carbon and a hydroxyl group bonded to an aliphatic carbon, and according to the present embodiment, any hydroxyl group can be substituted. Similar to the above-mentioned method for producing a polysaccharide derivative, a predetermined ionic liquid acts not only as a solvent but also as a catalyst to produce an esterified product of lignin.

As the raw material lignin, various conventionally known natural lignin and isolated lignin can be appropriately selected and used. Examples include natural lignins such as coniferous lignin, broadleaf lignin, and rice plant lignin, alkaline lignins such as lignosulfonic acid, kraft lignin, and soda lignin, and soda, which are obtained in large quantities from the pulp waste liquid of chemical pulping in the paper pulp manufacturing process. Isolated lignins (industrial lignins) such as anthraquinone lignin, organosol lignin, and blasted lignin can be mentioned. Any one of these lignins may be used, or two or more of these lignins may be used in combination.

In the method for producing a lignin derivative of the present embodiment, the types of ionic liquid, the type of aldehyde, and the reaction conditions applicable are the same as in the above-mentioned method for producing a polysaccharide derivative.

The produced lignin derivative further reacts with various reagents such as aldehyde by a conventional method using a base such as NaOH or an acid catalyst such as sulfuric acid for the purpose of modification or the like, or subsequently in the presence of an ionic liquid in the present invention. Can be converted to another lignin derivative.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Example 1) Reaction of cellulose and cinnamaldehyde in EmimOPy using an α, β-unsaturated structure as an internal oxidant 1-ethyl-3 of cellulose (120 mg, 2.22 mmol = [OH]) in a 20 mL Schlenk tube. It was dissolved in -methylimidazolium 2-pyridonate (EmimoPy) (456 mg, 2.22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that cellulose was uniformly dissolved in the solution, cinnamaldehyde (587 mg, 4.44 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 220 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired cellulose phenylpropionic acid ester. The degree of substitution was 3.0.
IR (ATR, cm ^-1 ) 1729 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.0-6.5 (br), 5.5-3.0 (br), 3.0-2.5 (br).

(Example 2) Reaction of cellulose and cinnamaldehyde in EmimOAc using an α, β-unsaturated structure as an internal oxidant 1-ethyl-3 of cellulose (120 mg, 2.22 mmol = [OH]) in a 20 mL Schlenck tube. -It was dissolved in methylimidazolium acetate (EmimOAc) (378 mg, 2.22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that cellulose was uniformly dissolved in the solution, cinnamaldehyde (293 mg, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 182 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was cellulose phenylpropionic acid acetate. The degree of substitution of the target phenylpropionic acid was 1.0, and the degree of substitution of acetic acid was 0.1.
IR (ATR, cm ^-1 ) 1729 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.0-6.5 (br), 5.5-3.0 (br), 3.0-2.5 (br), 2.2-1.7 ( br).

(Example 3) Reaction of cellulose and nonenal in EmimOPy using an α, β-unsaturated structure as an internal oxidant In a 20 mL Schlenk tube, cellulose (120 mg, 2.22 mmol = [OH]) is added to EmimOPy (456 mg, 2. It was dissolved in 22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, and nonenal (622 mg, 4.44 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 295 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired cellulose ester. It was confirmed that the recovered product was the desired cellulose nonanoic acid ester. The degree of substitution was 2.8.
IR (ATR, cm ^-1 ) 1742 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 5.5-3.0 (br), 2.5-0.6 (br).

(Comparative Example 1) Reaction of cellulose and cinnamaldehyde using a known catalyst system using an α, β-unsaturated structure as an internal oxidant References: Bode et al., Org. Lett., 2005, 7, 3873 -3876.
Cellulose (120 mg, 2.22 mmol = [OH]) was dried under reduced pressure at 80 ° C. for 3 hours in a 20 mL Schlenk tube. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that cellulose was not dissolved in the solution, and 2-mesityl-2,5,6,7-tetrahydropyroro [2,1-c] [1,2,4] triazole-4-ium. Chloride (29.0 mg, 0.11 mmol), diisopropylethylamine (28.4 mg, 0.22 mmol) and cinnamaldehyde (293 mg, 2.22 mmol) were added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 82.9 mg of a solid. From the analysis results of IR measurement, it was confirmed that the peak derived from the ester group was hardly observed, and the recovered material was cellulose as a starting material.

(Example 4) Reaction of cellulose and cinnamaldehyde in a 20 mL Schlenck tube, in which an α, β-unsaturated structure is used as an internal oxidant and an active ionic liquid species is generated in the reaction system by adding a base to BmimCl. (120 mg, 2.22 mmol = [OH]) was dissolved in 1-butyl-3-methylimidazolium chloride (BmimCl) (388 mg, 2.22 mmol), and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 1 hour. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, and cinnamaldehyde (559 μL, 4.44 mmol) and 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU, 102 mg,) were confirmed. 0.67 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 236 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired cellulose phenylpropionic acid ester. The degree of substitution was 1.6.
IR (ATR, cm ^-1 ) 1729 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.0-6.5 (br), 5.5-3.0 (br), 3.0-2.5 (br).

In this example, 1-butyl-3-methylimidazole iriden was partially produced as an intermediate by the reaction of BmimCl and DBU, and the intermediate acted as a catalyst in the reaction of cellulose and cinnamaldehyde. Conceivable.

(Example 5) Reaction of cellulose and cinnamon essential oil in EmimOPy using an α, β-unsaturated structure as an internal oxidant EmimOPy (456 mg, 2) of cellulose (120 mg, 2.22 mmol = [OH]) in a 20 mL Schlenk tube. It was dissolved in .22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that cellulose was uniformly dissolved in the solution, and cinnamon essential oil (containing cinnamaldehyde, concentration 73% by weight) (823 μL) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 237 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired cellulose phenylpropionic acid ester. The degree of substitution was 2.9.
IR (ATR, cm ^-1 ) 1729 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.0-6.5 (br), 5.5-3.0 (br), 3.0-2.5 (br).

(Example 6) Reaction of amylose and cinnamon essential oil in EmimOPy using an α, β-unsaturated structure as an internal oxidant In a 20 mL Schlenk tube, amylose (120 mg, 2.22 mmol = [OH]) is added to EmimOPy (456 mg, 2). It was dissolved in .22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that amylose was uniformly dissolved in the solution, and cinnamon essential oil (containing cinnamaldehyde, concentration 73% by weight) (823 μL) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 307 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired amylose phenyl propionic acid ester. The degree of substitution was 3.0.
IR (ATR, cm ^-1 ) 1739 .; ^{1 1} H NMR (600 MHz, CDCl ₃ ) δ; 7.5-6.5 (br), 5.5-3.0 (br), 3.0-2.0 (br).

(Example 7) Reaction of lignin and cinnamon essential oil in EmimOPy using an α, β-unsaturated structure as an internal oxidant In a 20 mL Schlenk tube, lignin (363 mg, 2.22 mmol = [OH]) is added to EmimOPy (456 mg, 2). It was dissolved in .22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that lignin was uniformly dissolved in the solution, and cinnamon essential oil (containing cinnamaldehyde, concentration 73% by weight) (823 μL) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 410 mg of a solid. From the analysis result of IR measurement, it was confirmed that the desired ester structure was introduced into the recovered product.
IR (ATR, cm ^-1 ) 1733.

(Example 8) Reaction of cellulose and benzaldehyde in EmimOPy using oxygen (in air) as an external oxidant In a 20 mL Schlenk tube, cellulose (120 mg, 2.22 mmol = [OH]) is added to EmimOPy (456 mg, 2.22 mmol). And dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with dried air was attached to the reaction vessel, the inside of the vessel was replaced with air, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, benzaldehyde (226 μL, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 118 mg of a solid. From the analysis results of IR and ¹ H NMR measurements, it was confirmed that the recovered product was the desired cellulose benzoic acid ester. The degree of substitution was 1.4.
IR (ATR, cm ^-1 ) 1714 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.3-6.9 (br), 5.8-3.0 (br).

(Example 9) Reaction of cellulose and benzaldehyde in EmimOAc using oxygen as an external oxidant Cellulose (120 mg, 2.22 mmol = [OH]) is dissolved in EmimOAc (378 mg, 2.22 mmol) in a 20 mL Schlenk tube. Drying under reduced pressure was performed at 80 ° C. for 3 hours. A balloon filled with oxygen was attached to the reaction vessel, the inside of the vessel was replaced with oxygen, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, benzaldehyde (226 μL, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 113 mg of a solid. Due to the low solubility of the recovered product, IR and ¹ H NMR measurements were performed after acetylation treatment. From the analysis results, it was confirmed that the recovered product before acetylation was the desired cellulose benzoic acid ester. The degree of substitution was 0.6.
IR (ATR, cm ^-1 ) 1711 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.2-7.0 (br), 5.5-3.0 (br), 2.2-1.5 (br).

(Example 10) Reaction of cellulose and benzaldehyde in EmimOAc using oxygen as an external oxidizing agent Cellulose (120 mg, 2.22 mmol = [OH]) is dissolved in EmimOAc (378 mg, 2.22 mmol) in a 20 mL Schlenk tube. It was dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with oxygen was attached to the reaction vessel, the inside of the vessel was replaced with oxygen, dehydrated DMF (3.44 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, benzaldehyde (226 μL, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 139 mg of a solid. Due to the low solubility of the recovered product, IR and ¹ H NMR measurements were performed after acetylation treatment. From the analysis results, it was confirmed that the recovered product before acetylation was the desired cellulose benzoic acid ester. The degree of substitution was 0.4.
IR (ATR, cm ^-1 ) 1711 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 8.2-7.0 (br), 5.6-3.0 (br), 2.2-1.5 (br).

(Comparative Example 2) Reaction of cellulose and benzaldehyde in EmimCl using oxygen as an external oxidant In a 20 mL Schlenk tube, 1-ethyl-3-methylimidazolium chloride (EmmCl) of cellulose (120 mg, 2.22 mmol = [OH]) is added. ) (325 mg, 2.22 mmol) and dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with oxygen was attached to the reaction vessel, the inside of the vessel was replaced with oxygen, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, benzaldehyde (226 μL, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 102 mg of a solid. From the analysis results of IR measurement, it was confirmed that the peak derived from the ester group was hardly observed, and the recovered material was cellulose as a starting material.

(Comparative Example 3) Reaction of Cellulose and Benzaldehyde in EmimOAc under an Argon Atmosphere In a 20 mL Schlenk tube, cellulose (120 mg, 2.22 mmol = [OH]) is dissolved in EmimOAc (378 mg, 2.22 mmol) at 80 ° C. Drying under reduced pressure was carried out for 3 hours. A balloon filled with argon gas was attached to the reaction vessel, the inside of the vessel was replaced with argon, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, benzaldehyde (226 μL, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 102 mg of a solid. From the analysis results of IR measurement, it was confirmed that the peak derived from the ester group was hardly observed, and the recovered material was cellulose as a starting material.

(Example 11) Reaction of cellulose and citronellal in EmimOPy using oxygen (in air) as an external oxidant In a 20 mL Schlenk tube, cellulose (120 mg, 2.22 mmol = [OH]) was added to EmimOPy (456 mg, 2.22 mmol). And dried under reduced pressure at 80 ° C. for 3 hours. A balloon filled with dried air was attached to the reaction vessel, the inside of the vessel was replaced with air, dehydrated DMSO (3.15 mL, 44.4 mmol) was added, and the mixture was stirred at 60 ° C. for 3 hours. After stirring, it was confirmed that the cellulose was uniformly dissolved in the solution, citronellal (342 mg, 2.22 mmol) was added to the reaction solution, and the mixture was stirred at 60 ° C. for 24 hours. The insoluble matter was precipitated by adding the reaction solution to an excess amount of methanol, and the solution was recovered after filtration and further washing with methanol. The insoluble material was dried overnight at 60 ° C. under reduced pressure to give 65 mg of a solid. Due to the low solubility of the recovered product, IR and ¹ H NMR measurements were performed after acetylation treatment. From the analysis results, it was confirmed that the recovered product before acetylation was the desired cellulose citroneric acid ester. The degree of substitution was 0.1.
IR (ATR, cm ^-1 ) 1728 .; ^{1 1} H NMR (600 MHz, Acetone-d ₆ ) δ; 5.5-3.0 (br), 2.2-0.7 (br).

Claims (11)

Many include a step of dissolving a raw material containing a polysaccharide in at least one ionic liquid having an azolium ion as a cation and an anionic conjugate acid having a pKa of 1 or more in vacuum and oxidatively reacting with an aldehyde. Method for producing a saccharide derivative. The method for producing a polysaccharide derivative according to claim 1, wherein the polysaccharide is cellulose. The method for producing a polysaccharide derivative according to claim 1 or 2, wherein the reaction is carried out in the presence of oxygen. The method for producing a polysaccharide derivative according to claim 1 or 2, wherein the aldehyde is an α, β-unsaturated aldehyde, and the reaction is carried out without using a separate oxidizing agent. The method for producing a polysaccharide derivative according to claim 4, wherein the α, β-unsaturated aldehyde is cinnamaldehyde. The polysaccharide according to any one of claims 1 to 5, wherein at least one of the ionic liquids having an azolium ion as a cation and a conjugate acid of an anion having a pKa of 1 or more in vacuum is produced during the reaction. Method for producing a saccharide derivative. A lignin derivative comprising a step of dissolving a raw material containing lignin in at least one ionic liquid in which the cation is an azolium ion and the pKa of the conjugate acid of the anion is 1 or more and oxidatively reacts with an aldehyde. Manufacturing method. The method for producing a lignin derivative according to claim 7, wherein the reaction is carried out in the presence of oxygen. The method for producing a lignin derivative according to claim 8, wherein the aldehyde is an α, β-unsaturated aldehyde, and the reaction is carried out without using a separate oxidizing agent. The method for producing a lignin derivative according to claim 9, wherein the α, β-unsaturated aldehyde is cinnamaldehyde. The lignin according to any one of claims 7 to 10 for producing at least one of the ionic liquids having an azolium ion as a cation and a conjugate acid of an anion having a pKa of 1 or more in vacuum during the reaction. Method for producing a derivative.