KR20210072855A - Method For Manufacturing 2,5-Furan dicarboxylic acid using 5-Acetoxymethyl-2-furaldehyde - Google Patents

Abstract

The present invention provides a method for manufacturing 2,5-furandicarboxylic acid (FDCA) using 5-acetoxymethyl-2-furaldehyde (AMF) which comprises the following steps: 1) preparing AMF by using an intermediate produced through the dehydration reaction of fructose; and 2) preparing FDCA through the oxidation reaction of AMF. According to the manufacturing method of the present invention, AMF can be obtained in a high yield by using the intermediate produced through the dehydration reaction of fructose, thereby being economical and efficient.

Description

Method for manufacturing 2,5-furan dicarboxylic acid (FDCA) using 5-acetoxymethyl-2-furaldehyde (AMF) {Method For Manufacturing 2,5-Furan dicarboxylic acid using 5-Acetoxymethyl-2-furaldehyde}

The present invention relates to a method for preparing 2,5-furandicarboxylic acid (FDCA) using 5-acetoxymethyl-2-furaldehyde (AMF). Specifically, 5-acetoxy from fructose After preparing methyl-2-furaldehyde (AMF), it relates to a method for preparing 2,5-furandicarboxylic acid (FDCA) through the oxidation reaction of the 5-acetoxymethyl-2-furaldehyde (AMF) will be.

Recently, many efforts have been made to replace petroleum resources using biomass-derived molecules that can be recycled and used repeatedly. For example, biofuels such as bioethanol and biodiesel, and bioplastic monomers such as lactic acid and propanediol are being industrially produced to replace petrochemicals.

In this regard, 2,5-furan dicarboxylic acid (hereinafter referred to as FDCA), which has been proposed as an alternative to terephthalic acid due to its structural similarity to terephthalic acid, which is a raw material of polyester, Various studies are in progress. As it is known that FDCA can be prepared from monosaccharide materials such as fructose, glucose, and galactose, an intermediate product from fructose is 5-hydroxymethyl-2-furaldehyde (5- There was an attempt to synthesize it through hyroxymethyl-2-furfural (hereinafter referred to as HMF).

However, since the reaction proceeds in a high boiling point polar solvent such as DMF and DMSO, it is difficult to purely separate and purify the intermediate HMF from the high boiling point polar solvent, and even if separated, HMF is unstable and needs to be stored frozen.

Accordingly, various attempts have been made to solve this problem.

Kroger group (2000) used a two-phase strategy to selectively oxidize HMF, dividing it into water and methyl isobutyl ketone (MIBK) layers and installing a polytetrafluorethylene membrane between them to prevent oxidation of fructose. Fructos are dehydrated to HMF through Lewatit SPC (solid acid catalyst) in the water layer, which passes through the membrane to the MIBK layer and is oxidized through PtBi/C (oxidation catalyst) to FDCA. Although FDCA was synthesized with a yield of 25% using this strategy, this method has a disadvantage in that the yield is also low and it is difficult to purify FDCA due to levulinic acid produced as a by-product (Topics in Catalysis, 13, (2000), 237- 242).

Ribeiro and Schuchardt group (2003) encapsulated Co(acac)3, which has two properties of oxidation/reduction, with sol-gel silica, and converted fructose (fructose) into FDCA with this catalyst. Although the conversion rate of fructose was 72% and the selectivity was 99%, it showed very good results, but the reaction proceeds at a high temperature of 165°C and a high pressure of 20 bar is required, so it is not practical for mass production process ( Catalysis Communications, 4, (2003) 83-86).

Zhang group (2014) carried out a two-step process of dehydrating fructose under isopropanol/HCl conditions, extracting isopropanol with water, purifying HMF, and oxidizing it with Au/HT catalyst. Although FDCA was synthesized from fructose raw material in 52% yield using this method, it is expensive to synthesize the Au/HT catalyst used during the reaction, and there is a problem in that humins, a by-product generated during the raw material reaction, deactivate the catalyst. (Chem Sus Chem, 7, (2014), 2131-2137).

To improve this, a synthesis method using polybenzylic ammonium chloride resin instead of HCl in the first step dehydration reaction was reported. Using this method, the FDCA synthesis yield can be increased up to 74%, but there are disadvantages in that the production cost increases while synthesizing polybenzylic ammonium chloride resin and Au/HT catalyst and the first step dehydration reaction is reacted at a high temperature of 140°C (ChemSusChem, 7, (2014), 2120-2124).

In the Sivaguru group (2014), the dehydration reaction of D-Fructose (fructose) was reacted in a DMA solvent using LiBr and H ₂ SO ₄ acid catalyst, and HMF was purified to synthesize FDCA in 63% yield. However, this reaction has the disadvantage that the yield of HMF is low as 45% and the need to use column chromatography in the HMF purification process makes it impractical to apply to mass production processes (Angew. Chem. Int. Ed. 53, (2014)). , 1-6).

Kroger, Topics in Catalysis, 13, (2000), 237-242

Ribeiro and Schuchardt, Catalysis Communications, 4, (2003) 83-86

ChemSus Chem, 7, (2014), 2131-2137; 2120-2124

Sivaguru, Angew, Chem. Int. Ed. 53, (2014), 1-6

An object of the present invention is to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

An object of the present invention is to obtain 5-acetoxymethyl-2-furaldehyde (5-Acetoxymethyl-2-furaldehyde, hereinafter referred to as AMF) in high yield using an intermediate produced through the dehydration reaction of fructose. .

Another object of the present invention relates to a method for producing high-purity FDCA from the AMF in an economical and efficient manner.

The present invention is

A) preparing 5-acetoxymethyl-2-furaldehyde (AMF) using the intermediate generated through the dehydration reaction of fructose; and

B) preparing 2,5-furan dicarboxylic acid (2,5-Furan dicarboxylic acid, FDCA) through the oxidation reaction of 5-acetoxymethyl-2-furaldehyde (AMF); 5- Containing Provided is a method for preparing 2,5-furandicarboxylic acid (FDCA) using acetoxymethyl-2-furaldehyde (AMF).

The step (a) is,

A-1) dehydrating fructose on an acid catalyst and a high-boiling polar solvent to prepare 5-hydroxymethyl-2-furfural (HMF) as an intermediate; and

A-2) acetylating the 5-hydroxymethyl-2-furfural (HMF) to prepare 5-acetoxymethyl-2-furaldehyde (AMF);

may include.

In the step (a-1), the acid catalyst is, Amberlyst 15, Nafion, Dowex, Nafion-silica composite (Nafion-Silica Composite), Keggin type heteropoly acid ( Keggin-type heteropoly acid, H _(8-x) XM ₁₂ O ₄₀ (X is P ⁵⁺ , Si ⁴⁺ or B ³⁺ , M ^{may be at least one selected from the group consisting of W 6+} or Mo ⁶⁺ ), Nb ₂ O ₅ , sulfuric acid, nitric acid, hydrochloric acid, and zeolite.

In step (A-1), the content of the acid catalyst may be 1 to 20% by weight based on the total weight of fructose.

In the step (A-1), the high boiling point polar solvent is dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1, 4-dioxane (1, 4-Dioxane), 1-methyl-2-pyrroly Don (NMP), dimethylaniline (DMA), and may be any one or more selected from the group consisting of sulfolane (Sulforane).

In step (A-1), the amount of the high boiling point polar solvent may be 3 to 20 times by weight relative to fructose.

The step (A-1) may be performed at 50 to 200 °C.

In step (A-2), the acetylating agent for the acetylation reaction is acetic anhydride or acetyl chloride, and 1 to 5 equivalents may be used relative to the content of fructose.

In step (A-2), after separating the organic layer from the reaction mixture obtained by the acetylation reaction of 5-hydroxymethyl-2-furfural (HMF), the separated organic layer was dried and filtered to obtain 5-acetoxy Methyl-2-furaldehyde (AMF) can be obtained.

The step (b) is,

b-1) oxidizing the 5-acetoxymethyl-2-furaldehyde (AMF) in an aqueous solution of an oxidizing agent and a base, followed by filtering; and

b-2) after adding acid to the filtrate, filtration, washing with water and drying to prepare 2,5-furandicarboxylic acid (FDCA); may include.

In the step (b-1), the oxidizing agent is potassium permanganate (KMnO ₄ ), hydrogen peroxide (Hydrogen peroxide), benzoyl peroxide (Benzoyl peroxide), peracetic acid (Peracetic acid), performic acid (Performic acid), perbenzoic acid (Perbenzoic) acid), sodium hypochlorite (NaOCl), manganese oxide (MnO ₂ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium cerium (IV) nitrate), ammonium peroxydisulfate, t -Butyl hydroperoxide (tert-Butylhydroperoxide), t-butyl hypochlorite (tert-Butyl hypochlorite), chromium trioxide (CrO ₃ ), cumenehydroperoxide (Cumenehydroperoxide), osmium tetraoxide (OsO ₄ ), potassium monoper Sulfate (KHSO ₅ ), and sodium percarbonate (Sodium percarbonate) may be at least one selected from the group consisting of.

In step (b-1), the content of the oxidizing agent may be 1 to 5 equivalents or less compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF).

In step (b-1), the base may be at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia and magnesium oxide.

In step (b-1), the content of the base may be 1 to 10 equivalents compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF).

In the step (b-1), the amount of water used in the aqueous base solution may be 5 to 50 times by weight relative to 5-acetoxymethyl-2-furaldehyde (AMF).

In the step (b-2), an acid may be added to the filtrate to adjust the pH to 0.1 to 2.

According to the production method of the present invention, AMF can be obtained in high yield by using the intermediate produced through the dehydration reaction of fructose, which is economical and efficient. Since the AMF is easy to separate and purify and is chemically stable, it can be easily used for the preparation of FDCA.

According to the manufacturing method of the present invention, it is economical and efficient to obtain FDCA of high purity at room temperature and atmospheric pressure without going through a complicated process through the oxidation reaction of AMF. Due to such high productivity, it can be easily applied to a large-capacity mass production line without a separate process condition change.

^{1 is a 1} H-NMR analysis result of AMF according to Experimental Example 1-1; and
^{2 is a 1} H-NMR analysis result of FDCA according to Experimental Example 2-1.

As described above, conventional HMF for FDCA synthesis was prepared through dehydration of fructose or glucose. However, HMF is not easy to separate from the reaction system for the following reasons, making it difficult to mass-produce commercially from an economic point of view.

First, it was mainly performed in a high boiling point polar solvent such as DMSO, so there was a difficulty in separation.

Second, since a lot of energy is required to evaporate the high boiling point solvent, the process cost could be increased.

Third, HMF could be seriously decomposed under the conditions for removing the high boiling point solvent.

Fourth, HMF, an intermediate, was unstable and had to be stored frozen.

Fifth, after being produced under the conditions of dehydration of fructose, it can be easily converted into low value-added compounds such as levulinic acid or humin, which caused a decrease in yield.

Sixth, since column chromatography must be used in the HMF purification process, it was difficult to apply it to the mass production process.

Accordingly, the inventors of the present invention confirmed that, after numerous studies and experiments, converting HMF obtained through the dehydration reaction of fructose to AMF solves the above problems and can be used to prepare FDCA applicable to mass production processes. and came to the present invention.

Specifically, the present invention

A) preparing AMF using the intermediate produced through the dehydration reaction of fructose; and

It provides a method for producing FDCA using AMF comprising; b) preparing FDCA through the oxidation reaction of the AMF.

According to the present invention, the intermediate produced through the dehydration reaction of fructose can be converted into high-purity AMF without a separate purification process, which is economical and efficient. In addition, the AMF can be easily used for the preparation of FDCA because it is chemically stable and has high lipophilicity.

In other words, it is economical and efficient to obtain high-purity FDCA at room temperature and pressure without going through a complicated process through the oxidation reaction of AMF. Due to such high productivity, it can be easily applied to a large-capacity mass production line without a separate process condition change.

AMF synthesis

Specifically, the step (a) is,

A-1) dehydrating fructose on an acid catalyst and a high-boiling polar solvent to prepare HMF as an intermediate; and

A-2) preparing AMF by acetylating the HMF by introducing an acetylation reagent to the reactant without additional separation/purification.

According to the present invention, after synthesizing HMF as an intermediate through dehydration of fructose, AMF can be converted through acetylation of HMF without a separate purification process. Thereafter, since AMF can be easily separated in the EA/H2O extraction system without a purification process by column chromatography, high-purity AMF with minimized impurity formation can be obtained. This process allows the AMF synthesis to be easily scalable to the kilogram level, which can ultimately lead to the mass production of FDCA.

In the step (a-1), the acid catalyst is, for example, Amberlyst 15, Nafion, Dowex, Nafion-Silica Composite (Nafion-Silica Composite), Keggin Keggin-type heteropoly acid (H _(8-x) XM ₁₂ O ₄₀ (X is P ⁵⁺ , Si ⁴⁺ or B ³⁺ , M ^{may be at least one selected from the group consisting of W 6+} or Mo ⁶⁺ ), Nb ₂ O ₅ , sulfuric acid, nitric acid, hydrochloric acid, and zeolite. Specifically, Amberlyst 15 absorbs water generated in the dehydration reaction of fructose to suppress hydrolysis of HMF while increasing the selectivity of HMF, so it can be preferably used.

In step (A-1), the content of the acid catalyst may be 1 to 20 wt % based on the total weight of fructose. When the content of the acid catalyst is less than 1% by weight based on the total weight of fructose, the AMF yield is reduced and thus the intended effect of the present invention is not obtained, and when it exceeds 20% by weight, the high unit price of Amberlyst 15 Although it causes an increase in cost, it is not preferable because there is no significant difference according to an increase in yield. Specifically, the content of the acid catalyst may be 2.5 to 15% by weight based on the total weight of fructose.

In step (A-1), the high boiling point polar solvent is, for example, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1, 4-dioxane (1, 4-Dioxane), 1-methyl It may be any one or more selected from the group consisting of -2-pyrrolidone (NMP), dimethylaniline (DMA), and sulfolane. Specifically, it may be dimethyl sulfoxide (DMSO) and/or dimethylformamide (DMF).

In step (A-1), the amount of the high boiling point polar solvent may be 3 to 20 times by weight relative to fructose. When the amount of the high-boiling polar solvent is less than three times that of fructose by weight, the AMF yield may decrease and thus the intended effect of the present invention may not be obtained. In addition, if it exceeds 20 times, the AMF yield may decrease, which is that the EA / H ₂ O extraction system in the AMF purification process requires a process to remove DMSO into an aqueous layer. In this process, the higher the volume of DMSO, the more DMSO This is because the amount of AMF lost to the water layer may also increase. Specifically, the amount of the high boiling point polar solvent may be 5 to 10 times by weight relative to fructose.

의 반응온도에서 수행될 수 있다. 상기 반응온도가 50

미만일 경우 반응속도가 느리고 반응전환율이 저하될 우려가 있고 200

를 초과할 경우 반응전환율은 높으나 AMF 분해가 과하게 이루어질 수 있어 바람직하지 않다. 상세하게는, 80 내지 120

의 반응온도에서 수행될 수 있다. The step (A-1) is, for example, 50 to 200

It can be carried out at a reaction temperature of the reaction temperature is 50

If it is less than 200, the reaction rate is slow and the reaction conversion rate may be lowered.

If it exceeds, the reaction conversion rate is high, but AMF decomposition may be excessively performed, which is not preferable. Specifically, 80 to 120

It can be carried out at a reaction temperature of

In the step (A-2), the acetylating agent that can be used for the acetylation reaction is not limited, but may be, for example, acetic anhydride or acetyl chloride.

The acetylating agent may be used in an amount of 1 to 5 equivalents based on the content of fructose. When the content of the acetylating agent is less than 1 equivalent, sufficient acetylation of HMF cannot be achieved, and when it exceeds 5 equivalents, there is a risk of side reactions, which is not preferable because the yield of AMF may be lowered.

In step (A-2), the acetylating agent may be at least one selected from the group consisting of acetic anhydride, acetyl chloride, acetyl bromide, ketene, and acetic acid, and specifically, it may be used in the presence of acetic anhydride.

After separating the organic layer from the reaction mixture obtained by the acetylation reaction of HMF, the separated organic layer may be dried and filtered to obtain AMF. _{Specifically, since the synthesized AMF can be easily separated in an EA/H 2} O extraction system without a purification process by column chromatography, high-purity AMF with minimized impurity formation can be obtained.

FDCA synthesis

The step (b) is,

b-1) oxidizing the AMF in an aqueous solution of an oxidizing agent and a base, followed by filtering; and

b-2) after adding acid to the filtrate, filtration, washing with water and drying to prepare FDCA; may include.

According to the present invention, FDCA of high purity can be easily obtained through the oxidation reaction of AMF. This reaction can be carried out at room temperature and pressure conditions, so it is economical and efficient. In addition, since it can be implemented in a mass production process without a separate process condition change, it can be directly applied in the industrial field.

In the step (b-1), the oxidizing agent, for example, potassium permanganate (KMnO ₄ ), hydrogen peroxide (Hydrogen peroxide), benzoyl peroxide (Benzoyl peroxide), peracetic acid (Peracetic acid), performic acid (Performic acid), Perbenzoic acid, sodium hypochlorite (NaOCl), manganese oxide (MnO ₂ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium cerium nitrate (Ammonium cerium (IV) nitrate), ammonium disulfate (Ammonium) peroxydisulfate), t-butyl hydroperoxide (tert-Butylhydroperoxide), t-butyl hypochlorite (tert-Butyl hypochlorite), chromium trioxide (CrO3), cumenehydroperoxide, osmium tetraoxide (OsO ₄ ), Potassium monopersulfate (KHSO ₅ ), and sodium percarbonate may be at least one selected from the group consisting of, specifically potassium permanganate (KMnO ₄ ).

In step (b-1), the content of the oxidizing agent may be 1 to 5 equivalents or less compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF). If the content of the oxidizing agent is less than 1 equivalent, it is difficult to obtain the intended effect of the present invention, and if it exceeds 5 equivalents, the amount of by-products after the reaction increases, making filtration difficult in the purification process, which is not preferable. Specifically, the content of the oxidizing agent may be greater than 1.7 equivalents and less than 3.0 equivalents.

In the step (b-1), the base may be an inorganic base, for example, it may be one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia and magnesium oxide.

In step (b-1), the content of the base may be 1 to 10 equivalents compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF). If the content of the base is less than 1 equivalent, it is difficult to obtain the intended effect of the present invention, and if it exceeds 10 equivalents, there is a fear that side reactions may occur after the reaction, but it is not preferable because there is no significant difference in the reaction effect. Specifically, the content of the oxidizing agent may be 3 to 8 equivalents.

In the step (b-1), the amount of water used in the aqueous base solution may be 5 to 50 times by weight relative to the AMF. If the amount of water used is less than 5 times, it is difficult to stir and the filtration process after the reaction is not easy, so it is difficult to obtain the intended effect of the present invention. it is not preferable to have Specifically, the amount of water used may be 10 to 35 times by weight relative to the AMF.

After adjusting the pH to 0.1 to 2 by adding an acid to the filtrate in step (b-2), the resulting brown solid is filtered, washed with water, and dried under vacuum to obtain FDCA in high yield. If the pH is high outside the above range, there is a risk that the 2,5-furandicarboxylate sodium salt form is not sufficiently converted to the carboxylic acid form FDCA in the acidification process and thus may not be precipitated as a solid. If the pH is too low, there is a difficulty in the reaction process. Not desirable. Specifically, the pH may be 0.1 to 1.

Hereinafter, the present invention will be described in detail through Examples, but the following Examples and Experimental Examples are merely illustrative of one aspect of the present invention, and the scope of the present invention is not limited by the Examples and Experimental Examples below. .

Preparation Example 1) AMF synthesis

1) Dehydration of D-Fructose

D-Fructose (10g, 55.5mmol) was added to the flask, DMSO (50mL) and Amberlyst-15 (0.5g, 5wt%) were added thereto, followed by reaction using a nitrogen balloon for 4 hours. The reaction temperature was 100 °C, and the reaction progress was confirmed by TLC. After completion of the reaction, Amberlyst-15 was recovered through filtration, and the second reaction was carried out immediately.

2) Acetylation of HMF

4-(Dimethylamino)pyridine (DMAP, 0.68g, 5.55mmol) and acetic anhydride (Ac ₂ O, 6.3mL, 66.6mmol) were added to the reaction solution and stirred at room temperature, and the reaction progress was confirmed by TLC. When the reaction is completed, the reactant is dissolved with ethyl acetate, washed several times with water, and the organic layer is separated. The organic layer is dried over Na ₂ SO ₄ , filtered, and the filtrate is vacuum distilled to obtain the desired compound, 5-Acetoxymethyl-2-furfural (AMF).

TLC confirmation: n-Hexane: Ethyl acetate = 1:2 Rf = 0.8, average yield 80%

Experimental Example 1-1) AMF ^One H-NMR

¹ H-NMR analysis of the synthesized material was performed and shown in FIG. 1 ( ¹ H-NMR (400 MHz, CDCl ₃ ) ∂: 9.65(s, 1H), 7.25(d, J=3.6Hz, 1H) , 6.62 (d, J = 3.6 Hz, 1H), 5.13 (s, 2H), 2.12 (s, 3H)).

Referring to FIG. 1 , it was confirmed that the synthesized in Preparation Example 1 was AMF.

After that, in the dehydration reaction of D-Fructose, the yield change of AMF according to the reaction conditions was confirmed. Except for the conditions changed below, it was carried out under the same conditions as the AMF synthesis process.

Experimental Example 1-2) Purification yield of AMF according to reaction conditions

Acid Catalyst Effect in Dehydration of D-Fructose

Example Amberlyst-15
Usage (wt%) reaction temperature
(℃) AMF's
Purification yield 1-1 2.5 100 67% 1-2 3 100 73% 1-3 5 100 81% 1-4 10 100 79% 1-5 15 100 78%

Referring to Table 1, it can be observed that the yield of AMF increases until the content of Amberlyst-15 becomes a certain amount, but after that, it can be observed that the yield of AMF is rather decreased, which is produced in the dehydration reaction of D-Fructose. It is presumed that Amberlyst-15 absorbs the used water to increase the selectivity of HMF while suppressing hydrolysis of HMF. However, in Examples 1 to 5, AMF can be obtained in high yield, which is a conventional acid catalyst. It is quite high compared to , but considering the high price of AMF, the optimal usage is 5 wt%.

Solvent Effect on Dehydration of D-Fructose

Example Solvent (weight to fructose) Amberlyst-15
Usage (wt%) AMF's
Purification yield 1-6 DMSO 5V* 5 81% 1-7 DMSO 10V 5 79% 1-8 DMSO 15V 5 77% 1-9 DMF 5V 5 76% 1-10 DMSO 2V / DMF 3V 5 79% 1-11 1,4-Dioxane 10V 50** 58%

(*Unit V means weight ratio to fructose)

** Dioxane uses 50wt% of Amberlyst-15 due to low reaction conversion rate)

Referring to Table 2, it can be seen that in the dehydration reaction of D-Fructose, AMF is obtained in a relatively high yield in DMSO 5V than DMSO 15V (meaning 15 times the weight of fructose) and DMSO 10V. In DMSO 15V and DMF 5V, AMF is synthesized in a similar yield. However, in the 1,4-dioxane 10V solvent condition, the reaction conversion rate was low, so Amberlyst-15 50wt% was used.

In the reaction using DMSO, it can be seen that the yield decreases little by little as the amount of DMSO increases. This reduction in yield is presumed to be a result of the loss of AMF in the purification process. The purification process _{requires the process of removing DMSO to the aqueous layer in the EA/H 2} O extraction system. In this process, the higher the volume of DMSO, the more the amount of AMF lost to the aqueous layer along with DMSO increases, which causes the AMF yield to drop. do. The degree of loss of AMF to the aqueous layer along with DMSO during the purification process was confirmed by measuring by GC.

Solvent Effect on Dehydration of D-Fructose

Example reaction temperature
(℃) Amberlyst-15
Usage (wt%) AMF's
Purification yield 1-12 80 5 53% 1-13 100 5 81% 1-14 120 5 72%

Referring to Table 3, the dehydration reaction of D-Fructose was slow at 80 ° C., and the reaction conversion rate was low, resulting in a low yield of 53%. At 120 ° C. It can be seen that the yield was obtained as low as 72%.

Preparation Example 2) FDCA synthesis

1) Oxidation of AMF

AMF (10g, 59.3mmol) synthesized in Preparation Example 1 was put into a 250mL flask, and H ₂ O (150mL) was added thereto. After adding NaOH (16.6 _{g, 415.4 mmol) to the reaction solution, KMnO 4} (22.5 g, 142.4 mmol) was carefully added. After stirring for at least 18 hours at room temperature and general atmospheric conditions, the reaction solution is filtered. Conc HCl was added to the filtrate to lower the pH to 1 or less, and the resulting brown solid was filtered. The filtered solid was washed with H ₂ O and then vacuum dried without further purification (HPLC purity: >99%).

Experimental Example 2-1) FDCA ^One H-NMR

¹ H-NMR analysis of the synthesized material was performed and shown in FIG. 2 (H-NMR (300MHz, DMSO-d6) ∂: 13.63 (2H, s, -COOH), 7.29 (2H, s, furan-) H)).

Referring to FIG. 2 , it was confirmed that the one synthesized in Preparation Example 2 was FDCA.

After that, the yield change of FDCA according to the reaction conditions in the AMF oxidation reaction was confirmed. Except for the conditions changed below, it was performed under the same conditions as the FDCA synthesis process.

Experimental Example 2-2) Purification yield of FDCA according to reaction conditions

In the AMF oxidation reaction, the oxidizing agent ₄ ) effect

Example KMnO ₄
equivalent weight reaction temperature
(℃) FDCA's
Purification yield 2-1 1.7 room temperature 32% 2-2 2.2 room temperature 48% 2-3 2.4 room temperature 60% 2-4 2.6 room temperature 58% 2-5 2.8 room temperature 57% 2-6 3.0 room temperature 55%

Referring to Table 4 _{, when the number of equivalents of KMnO 4} is 2.4 equivalents, the yield of FDCA is the highest at 60%, and as the _{number of equivalents of KMnO 4} increases from 2.6 equivalents to 3.0 equivalents, it can be seen that the yield of FDCA decreases. . The reason that the yield decreases slightly when the number of equivalents of _{KMnO 4 is 2.6 equivalents or more is that the more KMnO 4} is used, the more by-products after the reaction, and the by-products produced make it difficult to filter during the purification process. As the filtration process became difficult, a small amount of FDCA contained in the reaction by-product was not sufficiently filtered, so the yield decreased.

NaOH base effect in AMF oxidation reaction

Example inorganic base equivalent weight reaction temperature
(℃) FDCA's
Purification yield 2-7 NaOH 3 room temperature 32% 2-8 NaOH 4 room temperature 42% 2-9 NaOH 5 room temperature 51% 2-10 NaOH 6 room temperature 57% 2-11 NaOH 7 room temperature 60% 2-12 NaOH 8 room temperature 61%

Referring to Table 5, in the AMF oxidation reaction, the higher the number of equivalents of NaOH, the higher the yield of FDCA, but it can be seen that there is no significant difference in the purification yield in the reaction using 7 equivalents and 8 equivalents. In the AMF oxidation reaction, NaOH participates in the reaction when AMF is converted to HMF, and participates in the reaction together with _{KMnO 4 when the converted HMF is oxidized to FDCA through HMFCA as an intermediate.} The amount of NaOH used is determined to be important to use a minimum amount of NaOH because an acidification process using HCl is required in the purification process to obtain FDCA after the reaction, so it can be confirmed that the optimal number of equivalents of NaOH is 7 equivalents.

Effect of Change in Solvent Amount in AMF Oxidation Reaction

Example KMnO ₄
equivalent weight reaction temperature
(℃) FDCA's
Purification yield 2-1 1.7 room temperature 32% 2-2 2.2 room temperature 48% 2-3 2.4 room temperature 60% 2-4 2.6 room temperature 58% 2-5 2.8 room temperature 57% 2-6 3.0 room temperature 55%

(*Unit V means weight ratio to AMF)

Referring to Table 6, when H ₂ O 10V (meaning 10 times the weight of AMF) was used in the AMF oxidation reaction, stirring was difficult and the filtration process was not easy after the reaction, so the yield was 55%, H ₂ When O is used above 25V, filtration proceeds without any problem, but it can be seen that the amount of solid produced in the acidification process using HCl after filtration is reduced. The more H ₂ O is used, the more the solubility of FDCA increases and the yield of the solid obtained by filtration is lowered, so it can be seen that the optimal amount of _{H 2 O used is 15V.}

Claims (16)

A) preparing 5-acetoxymethyl-2-furaldehyde (AMF) using the intermediate generated through the dehydration reaction of fructose; and
b) preparing 2,5-furan dicarboxylic acid (2,5-Furan dicarboxylic acid, FDCA) through the oxidation reaction of the 5-acetoxymethyl-2-furaldehyde (AMF); A method for producing 2,5-furandicarboxylic acid (FDCA) using 5-acetoxymethyl-2-furaldehyde (AMF). According to claim 1, wherein the step (a),
A-1) dehydrating fructose on an acid catalyst and a high-boiling polar solvent to prepare 5-hydroxymethyl-2-furfural (HMF) as an intermediate; and
A-2) acetylating the 5-hydroxymethyl-2-furfural (HMF) to prepare 5-acetoxymethyl-2-furfuraldehyde (AMF);
2, 5-furandicarboxylic acid (FDCA) production method comprising a. The method according to claim 2, wherein in step (A-1),
The acid catalyst is, Amberlyst 15, Nafion (Nafion), Dowex (Dowex), Nafion-silica composite (Nafion-Silica Composite), Keggin-type heteropoly acid (Keggin-type heteropoly acid, H _{(8) -x)} XM ₁₂ O ₄₀ (X is P ⁵⁺ , Si ⁴⁺ or B ³⁺ , M is W ⁶⁺ or Mo ⁶⁺ ), Nb ₂ O ₅ , sulfuric acid, nitric acid, hydrochloric acid, and 2,5-furandicarboxylic acid, characterized in that at least one selected from the group consisting of zeolite (Zeolite) ( FDCA). The method according to claim 2, wherein in step (A-1),
The method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that the content of the acid catalyst is 1 to 20% by weight based on the total weight of fructose. The method according to claim 2, wherein in step (A-1),
The high boiling point polar solvent is dimethylsulfoxide (DMSO), dimethylformamide (DMF), 1,4-dioxane (1,4-Dioxane), 1-methyl-2-pyrrolidone (NMP), dimethylaniline (DMA) ) and a method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that at least one selected from the group consisting of sulfolane. The method according to claim 2, wherein in step (A-1),
The method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that the amount of the high-boiling polar solvent used is 3 to 20 times by weight relative to fructose. According to claim 2, wherein the step (A-1),
Method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that it is carried out at 50 to 200 ℃. The method according to claim 2, wherein in step (A-2),
The acetylating agent for the acetylation reaction is acetic anhydride or acetyl chloride, and the method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that 1 to 5 equivalents are used relative to the content of fructose. The method of claim 2, wherein in step (A-2),
After separating the organic layer from the reaction mixture obtained by the acetylation reaction of 5-hydroxymethyl-2-furfural (HMF), the separated organic layer was dried and filtered to obtain 5-acetoxymethyl-2-furfural (AMF) ) A method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that to obtain. According to claim 1, wherein the step (b),
b-1) oxidizing the 5-acetoxymethyl-2-furaldehyde (AMF) in an aqueous solution of an oxidizing agent and a base, followed by filtering; and
b-2) preparing 2,5-furandicarboxylic acid (FDCA) by adding acid to the filtrate, followed by filtration, washing with water and drying;
2, 5-furandicarboxylic acid (FDCA) production method comprising a. 11. The method of claim 10, wherein in step (b-1),
The oxidizing agent is potassium permanganate (KMnO ₄ ), hydrogen peroxide (Hydrogen peroxide), benzoyl peroxide (Benzoyl peroxide), peracetic acid (Peracetic acid), performic acid (Performic acid), perbenzoic acid (Perbenzoic acid), sodium hypochlorite (NaOCl) , manganese oxide (MnO ₂ ), potassium persulfate (K ₂ S ₂ O ₈ ), cerium ammonium nitrate (Ammonium cerium (IV) nitrate), ammonium peroxydisulfate, t-butyl hydroperoxide (tert-Butylhydroperoxide) ), tert-Butyl hypochlorite, chromium trioxide (CrO ₃ ), cumenehydroperoxide, osmium tetraoxide (OsO ₄ ), potassium monopersulfate (KHSO ₅ ), and sodium percarbonate (Sodium percarbonate) A method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that at least one selected from the group consisting of. 11. The method of claim 10, wherein in the step (B-1)
The method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that the content of the oxidizing agent is 1 to 5 equivalents or less compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF). 11. The method of claim 10, wherein in the step (B-1)
The base is a method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia and magnesium oxide. 11. The method of claim 10, wherein in the step (B-1)
Preparation of 2,5-furan dicarboxylic acid (FDCA), characterized in that the content of the base is 1 to 10 equivalents compared to the content of 5-acetoxymethyl-2-furaldehyde (AMF) Way. 11. The method of claim 10, wherein in the step (B-1)
The method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that the amount of water used in the aqueous base solution is 5 to 50 times by weight relative to 5-acetoxymethyl-2-furaldehyde (AMF). 11. The method of claim 10, wherein in the step (B-2)
A method for producing 2,5-furandicarboxylic acid (FDCA), characterized in that the pH is adjusted to 0.1 to 2 by adding an acid to the filtrate.

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