KR102560488B1 - Method of preparing 5-acyloxymethyl-2-furfural from d-fructose using immobilized enzyme and solid acid catalyst - Google Patents

Abstract

A method for producing 5-acyloxymethyl-2-furfural from D-fructose using an immobilized enzyme and a solid acid catalyst is disclosed. As shown in Scheme 1, the preparation method is as shown in Scheme 1, (a) trans-esterifying D-fructose, which is compound 1, and an acyl donor in the presence of an immobilized enzyme to prepare compound 2; and (b) preparing compound 3, 5-acyloxymethyl-2-furfural, by dehydrating compound 2 in the presence of a solid acid catalyst.
[Scheme 1]

In Scheme 1 above,
R ¹ is a C1 to C3 alkyl group.
The method for producing 5-acyloxymethyl-2-furfural of the present invention has a simple reaction route, a heterogeneous catalytic reaction using an immobilized enzyme and a cation exchange resin, a hybrid reaction using an enzyme and a chemical catalyst, easy separation and purification, and recycling of the catalyst is possible, resulting in high economic efficiency.
In addition, the production method of the present invention has mild reaction conditions that do not use high temperature / high pressure, and can efficiently produce 5-acyloxymethyl-2-furfural, especially 5-acetoxymethyl-2-furfural (AMF), by using a commercially available catalyst and a general-purpose solvent with low toxicity.

Description

Method for producing 5-acyloxymethyl-2-furfural from D-fructose using immobilized enzyme and solid acid catalyst

The present invention relates to a method for producing 5-acyloxymethyl-2-furfural, and more particularly, to a method for producing 5-acyloxymethyl-2-furfural, particularly 5-acetoxymethyl-2-furfural (AMF), from D-fructose using an immobilized enzyme and a solid acid catalyst.

Since the 19th century, fossil fuels have been developed and petroleum refining has been developed. Currently, many aspects of modern industry, from energy and bulk chemicals to refined materials, rely on petroleum, thus over-consuming these non-renewable resources. Recent research has shown great interest in using biomass resources as precursors for the production of polymeric materials, organic chemicals and fuels.

5-acetoxymethylfurfural, particularly 5-hydroxymethyl-2-furfural (HMF) and its derivatives, is one of the promising biomass-derived platform chemicals with the potential to become a “carbon-neutral” feedstock for renewable and sustainable industries. Numerous studies on the synthesis of HMF from various carbohydrate sources have been conducted in the past 30 years.

However, in HMF separation, reactions using polar solvents such as N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and sulfolane cause problems, and the HMF synthesis process using special reaction conditions such as microwave heating, ionic liquids, or supercritical solvents is not suitable for commercialization at present due to high synthesis cost. In addition, due to the low melting point (30-34 ° C.) of HMF and its excellent miscibility in both hydrophilic and hydrophobic solvents, options for the purification process are reduced, and it is difficult to obtain a high purity state due to difficult separation and purification.

An object of the present invention is to provide a method for preparing 5-acyloxymethyl-2-furfural, especially 5-acetoxymethyl-2-furfural (AMF), which has a simple reaction route as an alternative platform compound for HMF, easy separation and purification through a heterogeneous catalytic reaction using an immobilized enzyme and a cation exchange resin, and high economic feasibility because the catalyst can be recycled.

Another object of the present invention is to provide a method for efficiently producing 5-acyloxymethyl-2-furfural, particularly 5-acetoxymethyl-2-furfural (AMF), using a commercially available catalyst and a general-purpose solvent with low toxicity, under mild reaction conditions without using high temperature/high pressure.

According to one aspect of the present invention, as shown in Scheme 1, (a) trans-esterifying D-fructose, which is compound 1, and an acyl donor in the presence of an immobilized enzyme to prepare compound 2; and (b) preparing compound 3, 5-acyloxymethyl-2-furfural, by dehydrating compound 2 in the presence of a solid acid catalyst. A method for preparing 5-acyloxymethyl-2-furfural is provided.

[Scheme 1]

In Scheme 1 above,

R ¹ is a C1 to C3 alkyl group.

In addition, the acyl donor may be a compound represented by Formula 4 below.

[Formula 4]

In Formula 4,

R ¹ is a C1 to C3 alkyl group;

R ² is a C1 to C3 alkyl group, or ego,

R ³ is a hydrogen atom or a C1 to C3 alkyl group.

According to another embodiment, in Chemical Formula 4, R ¹ may be a methyl group, compound 2 may be 1,6-diacetylfructose (DAF), and compound 3 may be 5-acetoxymethyl-2-furfural (AMF).

In addition, the immobilized enzyme may be a lipase.

In addition, the immobilized enzyme may be one that is not used or one that is filtered and recycled after being used as a catalyst for the trans-esterification reaction.

In addition, step (a) is performed by a solution reaction using a solvent, and the solvent of step (a) may include at least one selected from the group consisting of water, methanol, ethanol, acetone, tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, ethyl acetate, methyl isobutyl ketone, hexane, and dichloromethane.

In addition, the solvent of step (a) may include at least one selected from the group consisting of tetrahydrofuran and 1,4-dioxane.

In addition, the solid acid catalyst may include a cation exchange resin.

In addition, the cation exchange resin may include Amberlyst 15.

In addition, step (b) may be performed by a solution reaction using a solvent, and the solvent of step (b) may include at least one selected from the group consisting of tetrahydrofuran, 1,4-dioxane, and dimethyl sulfoxide.

In addition, the solvent of the step (b) may include the 1,4-dioxane and the dimethylsulfoxide, and 10 to 100 parts by weight of the dimethylsulfoxide based on 100 parts by weight of the 1,4-dioxane.

In addition, the solid acid catalyst may be one in which a Bronsted acid or Lewis acid functional group is connected to an organic support or an inorganic support.

In addition, the solid acid catalyst may be unused or recycled after being used as a catalyst for the dehydration reaction.

In addition, in the step (b), the weight ratio of the solid acid catalyst to the compound 2 (solid acid catalyst/compound 2) may be 0.5 to 1.

In addition, the immobilized enzyme and the solid acid catalyst may be each independently immobilized on a carrier.

According to another aspect of the present invention, 5-acyloxymethyl-2-furfural prepared by the above production method is provided.

The method for producing 5-acyloxymethyl-2-furfural of the present invention has a simple reaction route, a heterogeneous catalytic reaction using an immobilized enzyme and a cation exchange resin, a hybrid reaction using an enzyme and a chemical catalyst, easy separation and purification, and recycling of the catalyst is possible, resulting in high economic efficiency.

In addition, the production method of the present invention has mild reaction conditions that do not use high temperature / high pressure, and can efficiently produce 5-acyloxymethyl-2-furfural, especially 5-acetoxymethyl-2-furfural (AMF), by using a commercially available catalyst and a general-purpose solvent with low toxicity.

1 is a graph showing the DAF yield and catalyst loss according to the number of reuses of the immobilized lipase of Example 3.
Figure 2 is a graph showing the yield of AMF and HMF and DAF conversion over time in the DAF dehydration reaction of Example 4-4.
3 is a graph showing the yield of AMF and HMF and the DAF conversion rate according to Examples 5-1 to 5-7.
4 is a graph showing yields of AMF and HMF according to Examples 5-2, 5-8 to 5-11.
5 is a graph showing AMF and HMF yields according to the number of reuses of Amberlyst 15 of Example 7.

Since the present invention can apply various transformations and have various embodiments, specific embodiments are exemplified and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Also, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention.

In addition, when a component is referred to as “on another component,” “formed on another component,” “located on another component,” or “laminated on another component,” it should be understood that although it may be directly attached to, positioned on, or stacked on the front or one surface of the other component, other components may be present in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but it should be understood that the presence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof is not excluded in advance.

In this specification, "hydrogen" means single hydrogen, double hydrogen, or tritium unless otherwise defined.

In the present specification, "alkyl (alkyl) group" means an aliphatic hydrocarbon group unless otherwise defined.

An alkyl group may be a "saturated alkyl group" that does not contain any double or triple bonds.

The alkyl group may also be an "unsaturated alkyl group" containing at least one double bond or triple bond.

Hereinafter, a method for preparing 5-acyloxymethyl-2-furfural of the present invention will be described with reference to Scheme 1.

[Scheme 1]

In Scheme 1 above,

R ¹ is a C1 to C3 alkyl group.

First, immobilized enzyme in the presence Compound 1, D- With D-Fructose acyl donor ( acyl donor) by trans-esterification to prepare compound 2 (step a).

The acyl donor may be a compound represented by Chemical Formula 4 below.

[Formula 4]

In Formula 4,

R ¹ is a C1 to C3 alkyl group;

R ² is a C1 to C3 alkyl group, or ego,

R ³ is a hydrogen atom or a C1 to C3 alkyl group.

The immobilized enzyme may be a lipase.

The immobilized enzyme may be one that is not used or one that is filtered and recycled after being used as a catalyst for the trans-esterification reaction.

Step (a) is carried out by a solution reaction using a solvent, and the solvent in step (a) may include at least one selected from the group consisting of water, methanol, ethanol, acetone, tetrahydrofuran, 1,4-dioxane, dimethylsulfoxide, ethyl acetate, methyl isobutyl ketone, hexane, and dichloromethane, and preferably at least one selected from the group consisting of tetrahydrofuran and 1,4-dioxane. can include

Finally, solid acid catalyst in the presence Compound 2 was subjected to a dehydration reaction to obtain compound 3, 5- acyloxymethyl -2-furfural is prepared (step b).

In Formula 4, R ¹ may be a methyl group, compound 2 may be 1,6-diacetylfructose (DAF), and compound 3 may be 5-acetoxymethyl-2-furfural (AMF).

The solid acid catalyst may include a cation exchange resin.

The cation exchange resin may include Amberlyst 15.

Step (b) is performed as a solution reaction using a solvent, and the solvent of step (b) may include at least one selected from the group consisting of tetrahydrofuran, 1,4-dioxane, and dimethylsulfoxide.

The solvent of the step (b) includes the 1,4-dioxane and the dimethylsulfoxide, and may include 10 to 100 parts by weight of the dimethylsulfoxide based on 100 parts by weight of the 1,4-dioxane.

The solid acid catalyst may be one in which a Bronsted acid or Lewis acid functional group is connected to an organic support or an inorganic support.

The solid acid catalyst may be unused or recycled after being used as a catalyst for the dehydration reaction.

In the step (b), the weight ratio of the solid acid catalyst to the compound 2 (solid acid catalyst/compound 2) may be 0.5 to 1.

The immobilized enzyme and the solid acid catalyst may be each independently immobilized on a carrier.

In addition, the present invention provides 5-acyloxymethyl-2-furfural prepared by the above preparation method.

[Example]

Hereinafter, the present invention will be described in more detail by way of examples. However, this is for illustrative purposes and the scope of the present invention is not limited thereby.

실시예에서 사용한 시약인, D-Fructose (99%), 5-hydroxymethyl-2-furfural (HMF, 99%), 5-acetoxymethyl-2-furfural(AMF, 99%), vinyl acetate (99%), tetrahydrofuran (anhydrous, 99.9%, abbreviated as THF henceforth), 1,4-dioxane (anhydrous, 99.8%, abbreviated as dioxane henceforth), DMSO (anhydrous, 99.9%), sulfuric acid (H ₂ SO ₄ 95-98%), p-toluenesulfonic acid monohydrate (pTSA, 98.5%), alumina (Al ₂ O ₃ , activated, acidic, Brockmann I), and Amberlyst 15 (hydrogen form, dry)를 Sigma-Aldrich사에서 구매하여 사용하였다. Immobilized lipases such as Novozym 435 and Lipozyme TL IM were purchased from Novozymes (Denmark), and Lipozyme RM IM was purchased from Sigma-Aldrich.

Example

Example 1: DAF Preparation

[Scheme 1]

Example 1-1

Referring to Scheme 1, 50 mg of D-fructose, 80 μL of vinyl acetate (3 equivalents), 50 mg of immobilized lipase Lipozyme TL IM as an immobilized enzyme, and 5 mL of water (H ₂ O) as a solvent were reacted at 45 ° C. for 5 hours at 300 rpm with magnetic stirring. After the reaction, the lipase was filtered, and the filtrate was rotary evaporated and vacuum evaporated to obtain DAF as a final product in the form of a slight yellow syrup.

¹ H NMR of DAF (300 MHz, CDCl ₃ ): 4.44-4.33 (m, 1H on C2), 4.30-4.23 (m, 2H of C5-CH ₂ ), 4.21-4.13 (m, 2H on C3 and C4), 4.05-4.00 (m, 2H of C2-CH ₂ ), 2. 17-2.12 (m, 6H of 2 -COOCH3; major anomer: 2.14 and 2.13; minor anomer: 2.17 and 2.12).

¹³ C NMR of DAF (300 MHz, DMSO-d ₆ ): 170.83-170.47 (d, 2C in -COO- groups), 100.86 (s, C5 in the ring), 78.85 (s, C2 in the ring), 76.49 (s, C4 in the ring), 75.57 (s, C3 in the ring), 66. 16 (s, C6 in -CH ₂ group), 64.62 (s, C1 in -CH ₂ group), 21.04 (m, 2C in -CH ₃ groups)

LC-MS analysis with API-ES positive mode +70 V (in HCOOH 0.001 M), m/z: 282.2 (M + H ₂ O, 38%), 247.1 (M - OH ^- , 100%).

Examples 1-2 to 1-35

Examples 1-2 to 1-35 were prepared in the same manner as in Example 1-1, except that the equivalents of the solvent, immobilized enzyme, and vinyl acetate described in Table 1 below were used instead of the equivalents of the solvent, the immobilized enzyme, and the vinyl acetate of Example 1-1, respectively, to prepare DAF.

Table 1 below summarizes the types of solvents, types of immobilized enzymes, and equivalents of vinyl acetate used in the preparation of DAFs in Examples 1-1 to 1-35.

menstruum immobilized enzyme Equivalents of vinyl acetate (equiv) Example 1-1 water (H ₂ O) Lipozyme TL IM 3 Example 1-2 water (H ₂ O) Lipozyme RM IM 3 Example 1-3 water (H ₂ O) Novozym 435 3 Example 1-4 MeOH Lipozyme TL IM 3 Example 1-5 MeOH Lipozyme RM IM 3 Example 1-6 MeOH Novozym 435 3 Examples 1-7 EtOH Lipozyme TL IM 3 Examples 1-8 EtOH Lipozyme RM IM 3 Examples 1-9 EtOH Novozym 435 3 Examples 1-10 Acetone Lipozyme TL IM 3 Example 1-11 Acetone Lipozyme RM IM 3 Examples 1-12 Acetone Novozym 435 3 Examples 1-13 THF Lipozyme TL IM 3 Examples 1-14 THF Lipozyme RM IM 3 Examples 1-15 THF Novozym 435 3 Examples 1-16 1,4-Dioxane Lipozyme TL IM 3 Examples 1-17 1,4-Dioxane Lipozyme RM IM 3 Examples 1-18 1,4-Dioxane Novozym 435 3 Examples 1-19 DMSO Lipozyme TL IM 3 Examples 1-20 DMSO Lipozyme RM IM 3 Example 1-21 DMSO Novozym 435 3 Examples 1-22 Ethyl acetate Lipozyme TL IM 3 Examples 1-23 Ethyl acetate Lipozyme RM IM 3 Examples 1-24 Ethyl acetate Novozym 435 3 Examples 1-25 MIBK Lipozyme TL IM 3 Examples 1-26 MIBK Lipozyme RM IM 3 Examples 1-27 MIBK Novozym 435 3 Examples 1-28 Hexane Lipozyme TL IM 3 Examples 1-29 Hexane Lipozyme RM IM 3 Examples 1-30 Hexane Novozym 435 3 Examples 1-31 Dichloromethane Lipozyme TL IM 3 Example 1-32 Dichloromethane Lipozyme RM IM 3 Example 1-33 Dichloromethane Novozym 435 3 Example 1-34 THF Novozym 435 5 Examples 1-35 Dioxane Novozym 435 5

Example 2: DAF for manufacturing scale up (×10 times to ×600 times)

Example 2-1: THF solvent (×10 times)

0.5 g of D-fructose, 800 μL of vinyl acetate (3 equivalents), and immobilized lipase Novozym 435 were reacted with the same weight (0.5 g) as D-fructose and 50 mL of THF as a solvent by magnetic stirring at 45° C. for 5 hours at 300 rpm. After the reaction, the lipase was filtered, and the filtrate was rotary evaporated and vacuum evaporated to obtain DAF as a final product in the form of a slight yellow syrup.

Examples 2-2 to 2-5: THF solvent

DAF was prepared by performing Examples 2-2 to 2-5 in the same manner as Example 2-1, except that 1.0 g, 1.5 g, 2.0 g, and 2.5 g of D-fructose were used instead of 0.5 g of D-fructose.

Example 2-6: THF solvent (×600 times)

30.0 g of D-fructose was used instead of 0.5 g of D-fructose, 46 mL of vinyl acetate (3 equivalents) was used instead of 800 μL of vinyl acetate (3 equivalents), 3 L of THF was used instead of 50 mL of THF as solvent, and magnetic stirring was at 500 rpm for 6 hours instead of magnetic stirring at 300 rpm for 5 hours. DAF was prepared by performing Example 2-6 in the same manner as Example 2-1.

Examples 2-7 to 2-11: 1,4-Dioxane solvent

DAF was prepared by performing Examples 2-7 to 2-11 in the same manner as in Examples 2-1 to 2-5, except that 50 mL of 1,4-dioxane was used instead of 50 mL of THF as a solvent.

Example 3: Reuse of immobilized lipase (Novozym 435)

500 mg of D-fructose, 500 mg of immobilized lipase Novozym 435, 800 μL of vinyl acetate, and 50 mL of THF as a solvent were reacted at 45° C. for 5 hours with magnetic stirring at 300 rpm. After the reaction, the lipase was filtered, and the filtrate was rotary evaporated and vacuum evaporated to obtain DAF as a final product in the form of a slight yellow syrup.

This process was repeated 7 cycles. After each cycle, the lipase in the form of small beads was filtered off, washed with THF and dried at room temperature for 12 hours before reuse.

Example 4: Preparation of AMF using a single solvent

[Scheme 2]

Example 4-1: Using THF as a single solvent

Referring to Scheme 2, 50 mg of DAF, 50 mg of Amberlyst 15 as a solid acid catalyst, and 5 mL of THF as a solvent were stirred at 120° C. for 8 hours at 300 rpm to react. After the reaction, Amberlyst 15 was filtered, and AMF was separated through vacuum distillation to prepare AMF as a final product.

¹ H NMR (300 MHz, THF-d ₈ ): 9.62 (s, 1H on -CHO), 7.31-7.30 (d, 1H of C4 on furan ring), 6.68-6.67 (d, 1H of C3 on furan ring), 5.13 (s, 2H of -CH ₂ ), 2.06 (s, 3H of -CH ₃ ).

¹³ C NMR of AMF (300 MHz, THF-d ₈ ): 176.91 (s, C in -CHO group), 169.23 (s, C in -COO- group), 155.57 (s, C2 in the furan ring), 155.37 (s, C5 in the furan ring), 120.62 (s, C4 in the furan ring), 11 2.06 (s, C3 in the furan ring), 57.27 (s, C in -CH ₂ group), 19.32 (s, C in -CH ₃ group).

GC-MS analysis with EI scan mode from -2.0 to +2.0 kV shows m/z: 282.2 (M - COCH ₃ + H+, 100%).

Example 4-2: Use of 1,4-Dioxane as a single solvent

AMF was prepared by performing Example 4-2 in the same manner as Example 4-1, except that 1,4-Dioxane was used instead of THF as a solvent.

Example 4-3: Using DMSO as a single solvent

AMF was prepared by performing Example 4-3 in the same manner as Example 4-1, except that DMSO was used instead of THF as a solvent.

Example 4-4: Using 1,4-Dioxane as a single solvent

AMF was prepared in Example 4-4 in the same manner as in Example 4-1, except that 10 mg of Amberlyst 15 was used instead of 50 mg of Amberlyst 15, and 1,4-Dioxane was used instead of THF as a solvent.

Example 5: Preparation of AMF using a mixed solvent of 1,4-dioxane and DMSO

Example 5-1

50 mg of DAF, 50 mg of Amberlyst 15 as a solid acid catalyst, and 5 mL of a mixed solvent having a weight ratio of 1,4-dioxane and DMSO of 90:10 as a solvent were stirred and reacted at 120 ° C. for 8 hours at 300 rpm. After the reaction, Amberlyst 15 was filtered, and AMF was separated through vacuum distillation to prepare AMF as a final product.

Examples 5-2 to 5-11

AMF was prepared by performing Examples 5-2 to 5-11 in the same manner as in Example 5-1, except that the mixed solvent of 1,4-dioxane and DMSO in Example 5-1 in a weight ratio of 90:10, and the mixed solvent of 1,4-dioxane and DMSO mixed in the weight ratio shown in Table 2 below instead of 50 mg of Amberlyst 15, and the amount of Amberlyst 15, respectively.

Table 2 below summarizes the weight ratio of the mixed solvent of 1,4-dioxane and DMSO, the amount of Amberlyst 15, and Amberlyst 15/DA used in the preparation of AMFs in Examples 5-1 to 5-11.

Weight ratio of 1,4-Dioxane:DMSO Amberlyst 15
(mg) Amberlyst 15/DAF
(Cat/Sub, w/w, R) Example 5-1 90:10 50 One Example 5-2 85:15 50 One Example 5-3 80:20 50 One Example 5-4 75:25 50 One Example 5-5 70:30 50 One Example 5-6 60:40 50 One Example 5-7 50:50 50 One Example 5-8 85:15 10 0.2 Example 5-9 85:15 20 0.4 Examples 5-10 85:15 30 0.6 Example 5-11 85:15 40 0.8

Example 6: AMF for manufacturing scale up (×10 times to ×100 times)

Example 6-1: (×10 times)

0.5 g of DAF, Amberlyst 15 as a solid acid catalyst, Amberlyst 15/DAF (R _{Cat / Sub} ) is a weight (0.3 g) of 0.6, and 50 mL of a mixed solvent having a weight ratio of 1,4-dioxane and DMSO of 85:15 as a solvent. Stirred at 300-500 rpm for 8 hours at 120 ° C. and reacted. After the reaction, Amberlyst 15 was filtered, and AMF was separated through vacuum distillation to prepare AMF as a final product.

Examples 6-2 to 6-5

DAF was prepared by performing Examples 6-2 to 6-5 in the same manner as in Example 6-1, except that 1.0 g, 2.0 g, 4.0 g, and 5.0 g of DAF were respectively used instead of 0.5 g of DAF.

Example 7: Reuse of Amberlyst 15

50 mg of DAF, 30 mg of Amberlyst 15, and 5 mL of a mixed solvent having a weight ratio of 1,4-dioxane and DMSO as solvents of 85:15 were stirred at 120° C. for 8 hours at 300 rpm to react. After the reaction, Amberlyst 15 was filtered, and AMF was separated through vacuum distillation to prepare AMF as a final product.

This process was repeated 5 cycles. After each cycle, the Amberlyst 15 was filtered, washed with acetone and dried in a vacuum oven (25° C.) before reuse.

[Test Example]

Test Example 1: DAF yield analysis according to solvent and lipase type

The yields of DAF prepared according to Examples 1-1 to 1-35 are shown in Table 3 below. The yield of DAF was calculated using Equation 1 below.

[Equation 1]

menstruum immobilized enzyme Equivalents of vinyl acetate (equiv) DAF yield (%) Example 1-1 water (H ₂ O) Lipozyme TL IM 3 0.0 Example 1-2 water (H ₂ O) Lipozyme RM IM 3 0.0 Example 1-3 water (H ₂ O) Novozym 435 3 0.0 Example 1-4 MeOH Lipozyme TL IM 3 0.0 Example 1-5 MeOH Lipozyme RM IM 3 0.0 Example 1-6 MeOH Novozym 435 3 0.0 Examples 1-7 EtOH Lipozyme TL IM 3 0.0 Examples 1-8 EtOH Lipozyme RM IM 3 0.0 Examples 1-9 EtOH Novozym 435 3 0.0 Examples 1-10 Acetone Lipozyme TL IM 3 7.4±1.2 Example 1-11 Acetone Lipozyme RM IM 3 0.0 Examples 1-12 Acetone Novozym 435 3 12.7±2.4 Examples 1-13 THF Lipozyme TL IM 3 44.3±2.7 Examples 1-14 THF Lipozyme RM IM 3 30.1±2.3 Examples 1-15 THF Novozym 435 3 96.2±2.8 Examples 1-16 1,4-Dioxane Lipozyme TL IM 3 37.4±3.2 Examples 1-17 1,4-Dioxane Lipozyme RM IM 3 22.5±1.8 Examples 1-18 1,4-Dioxane Novozym 435 3 90.4±2.5 Examples 1-19 DMSO Lipozyme TL IM 3 0.0 Examples 1-20 DMSO Lipozyme RM IM 3 0.0 Example 1-21 DMSO Novozym 435 3 0.0 Example 1-22 Ethyl acetate Lipozyme TL IM 3 9.1±2.1 Examples 1-23 Ethyl acetate Lipozyme RM IM 3 0.0 Examples 1-24 Ethyl acetate Novozym 435 3 14.4±2.2 Example 1-25 MIBK Lipozyme TL IM 3 5.7±1.9 Examples 1-26 MIBK Lipozyme RM IM 3 0.0 Examples 1-27 MIBK Novozym 435 3 9.7±1.8 Example 1-28 Hexane Lipozyme TL IM 3 0.0 Examples 1-29 Hexane Lipozyme RM IM 3 0.0 Examples 1-30 Hexane Novozym 435 3 0.0 Example 1-31 Dichloromethane Lipozyme TL IM 3 0.0 Example 1-32 Dichloromethane Lipozyme RM IM 3 0.0 Example 1-33 Dichloromethane Novozym 435 3 0.0 Example 1-34 THF Novozym 435 5 95.5±2.9 Examples 1-35 1,4-Dioxane Novozym 435 5 92.2±2.3

Referring to Table 3 above, it can be seen that all three types of lipases can catalyze the trans-esterification reaction when an ether-type solvent (THF or 1,4-dioxane) is used as the reaction medium. When using Novozym 435 with THF or 1,4-dioxane, the formation of DAF was most favorable with yields of DAF of 96.2% and 90.4% in THF (Examples 1-15) and 1,4-dioxane (Examples 1-18), respectively.

On the other hand, water containing a -OH functional group (Examples 1-1 to 1-3) and solvent (Examples 1-4 to 1-9) prevented the exchange of the primary -OH group of D-fructose with an acetyl group from an acyl donor, so the trans-esterification reaction naturally did not occur.

Solvents with medium and low polarity indices yielded little or no DAF yield because they could hardly dissolve D-fructose (Examples 1-10 to 1-12, 1-22 to 1-33), so that D-fructose did not dissolve and the reaction remained stationary when contacted with immobilized lipase.

It was also observed that the yield of DAF was not improved even when an excess of the acyl donor (5 equivalents of vinyl acetate) was used (Examples 1-34 and 1-35).

Therefore, THF and 1,4-dioxane were used as solvents for the scale-up procedure, and Novozym 435 was chosen as the catalyst.

Test Example 2: Analysis of scale-up results for DAF production

The type of solvent, the amount of D-fructose used, the D-fructose conversion rate, the DAF yield, and the DAF selectivity of Examples 2-1 to 2-11 are shown in Table 4 below. The D-fructose conversion rate was calculated using Equation 2 below, the DAF yield was calculated using Equation 1 above, and the DAF selectivity was calculated using Equation 3 below.

[Equation 2]

[Equation 3]

menstruum D-fructose (g) scale up D-fructose conversion rate
(%) DAF yield
(%) DAF selectivity
(%) Example 2-1 THF 0.5 ×10 100 94.6 94.6 Example 2-2 THF 1.0 ×20 98.3 90.1 91.6 Example 2-3 THF 1.5 ×30 90.1 82.8 91.9 Example 2-4 THF 2.0 ×40 83.5 77.3 92.6 Example 2-5 THF 2.5 ×50 76.7 71.7 93.5 Example 2-6 THF 30.0 ×600 92.0 88.0 95.6 Examples 2-7 1,4-Dioxane 0.5 ×10 100 91.3 91.3 Example 2-8 1,4-Dioxane 1.0 ×20 95.7 86.7 90.6 Examples 2-9 1,4-Dioxane 1.5 ×30 88.8 80.2 90.3 Examples 2-10 1,4-Dioxane 2.0 ×40 79.9 75.4 94.4 Examples 2-11 1,4-Dioxane 2.5 ×50 73.4 69.4 94.6

The results in Table 4 above show that the scale-up has little effect on the conversion of D-fructose as well as the formation of DAF. Referring to Table 4, a DAF yield of 88.0% was achieved with a D-fructose conversion of 92% in a 600-fold scale-up reaction (Examples 2-6) by slightly adjusting the reaction time and stirring speed. These results indicate that the trans-esterification of D-fructose using an immobilized enzyme catalyst is a fairly stable procedure and can be used for sustainable production of DAF. One major setback of this procedure is that when the concentration of the starting material increases from 1% w/v to 5% w/v, the yield of DAF begins to decrease accordingly. A 22.9% yield reduction in THF and a 21.9% yield reduction in 1,4-dioxane were recorded. That is, it was difficult to achieve a high yield of DAF without completely dissolving D-fructose using a large amount of solvent in the initial state of the reaction.

test example 3: immobilized lipase ( Novozym 435) according to the number of reuses DAF yield analysis

1 is a graph showing the DAF yield and catalyst loss according to the number of reuses of the immobilized lipase of Example 3. Referring to FIG. 1, Novozym 435 can be reused up to 5 cycles with a weight reduction of less than 9%, and at this time, the DAF yield is reduced to less than 5%, confirming that it provides a stable yield of DAF. Further reuse resulted in more than 10% catalyst loss as well as a higher reduction in DAF yield with 10.4% and 13.7% reduction in DAF yield for 6 and 7 reuses, respectively. Loss of catalyst can be explained by partial fragmentation of the catalyst beads during the long reaction and these fragments were lost during recovery and transfer between cycles. As observed in Figure 1, an increase in catalyst loss was associated with a decrease in DAF yield.

Test Example 4: Yield analysis of AMF and HMF over time in the dehydration reaction of DAF

Figure 2 is a graph showing the yield of AMF and HMF and DAF conversion over time in the DAF dehydration reaction of Example 4-4. DAF diluted in 1,4-dioxane was heated at 120° C. and samples were taken at specific time intervals for HPLC analysis. Referring to Figure 2, it was observed that both AMF and HMF were formed and AMF was the main product. After 8 hours, the highest AMF yield of 23.6% and HMF yield of 8.2% were achieved. Further prolongation of the response did not show an increase in AMF amount. It was believed that relatively low yields of AMF could be improved when reaction conditions such as solvent medium or catalyst amount were adjusted. In addition, the simultaneous formation of AMF and HMF in the reaction medium suggested that both dehydration and hydrolysis were catalyzed in the presence of Amberlyst 15.

Test Example 5: Yield analysis of AMF and HMF according to single solvent type

Since DAF is synthesized and readily soluble in THF or 1,4-dioxane, we tested whether these solvents are suitable for the dehydration reaction of DAF. In addition, DMSO was also investigated because, unlike HMF, AMF can be easily separated from DMSO by liquid-liquid extraction. The DAF conversion rates and yields of AMF and HMF according to Examples 4-1 to 4-3 are shown in Table 5 below.

DAF conversion rate, AMF yield and HMF yield were calculated using Equations 4 to 6, respectively.

[Equation 4]

[Equation 5]

[Equation 6]

menstruum DAF Conversion Rate (%) AMF yield (%) HMF yield (%) Example 4-1 THF 12.9±1.0 6.1±1.6 3.8±0.8 Example 4-2 1,4-Dioxane 51.2±1.2 29.2±2.1 15.6±1.7 Example 4-3 DMSO 59.2±1.4 38.7±2.4 14.9±1.9

Referring to Table 5, it was confirmed that THF as a dehydration solvent was inferior to 1,4-dioxane and DMSO. It was understood that this was because THF had a low boiling point (66 °C) and was not very effective in dehydrating DAF, which was carried out at a much higher temperature (120 °C). The AMF yield in 1,4-dioxane was 23.6% when 10 mg of Amberlyst 15 was used (see FIG. 2) and 29.2% when 50 mg of Amberlyst 15 was used. Although the amount of Amberlyst 15 used was increased from 10 mg to 50 mg, the AMF yield was not significantly improved. When increasing the amount of Amberlyst 15, the yield of HMF in 1,4-dioxane was quite remarkable, from 8.2% to 15.6%. This may be an indication that the hydrolysis reaction in 1,4-dioxane is slightly more favorable when more acid catalyst is added.

Also, referring to Table 5, DMSO had the highest AMF yield, and DMSO was widely and effectively used as a solvent for dehydration of ketose-type sugars into furan compounds. Several studies have mentioned that DMSO can stabilize HMF and reduce side reactions during dehydration. Therefore, it was understandable that DMSO had a high total yield of HMF and AMF.

Test Example 6: Yield of AMF and HMF according to the weight ratio of the mixed solvent

Referring to Table 5 above, considering that 1,4-dioxane (101 ° C.) has a much lower boiling point than DMSO (189 ° C.), the AMF yield (29.2%) in 1,4-dioxane is AMF in DMSO. When compared to the yield (38.7%), it did not fall far behind. Therefore, DMSO and 1,4-dioxane were combined as a mixed solvent for further investigation with the goal of maximizing the yield of AMF while limiting the formation of HMF.

3 is a graph showing the yield of AMF and HMF and the DAF conversion rate according to Examples 5-1 to 5-7. Referring to FIG. 3 , using DMSO as the mixed solvent greatly improved the formation of AMF while still maintaining a low yield of HMF. The best condition was a mixed solvent of 15% DMSO in 1,4-dioxane, where the yields of AMF and HMF were 55.8% and 9.0%, respectively. When the ratio of DMSO to 1,4-dioxane was increased above 20%, the AMF yield started to decrease.

As mentioned that AMF and HMF were simultaneously formed during the reaction, when DMSO was mixed with the mixed solvent at a specific ratio, the mixed solvent had a positive effect on the dehydration of DAF to furan compounds. First, added DMSO has the advantage of increasing the boiling point of the reaction medium, which makes the mixed solvent more suitable for dehydration at high temperatures (120° C.). Second, the presence of DMSO can have a catalytic activity to remove H ₂ O molecules from the furanose ring, as well as reduce the formation of byproducts and stabilize AMF and HMF formed in the reaction mixture.

Test Example 7: Yield of AMF and HMF according to the ratio of Amberlyst 15 and DAF

Since Amberlyst 15 is a H ⁺ type cation exchange resin with a macro-reticular pore structure, dehydration of DAF in this case is catalyzed heterogeneously at hydrogen ion sites located throughout the resin beads. A higher amount of catalyst is expected to lead to a better AMF yield for a longer reaction time. With this in mind, the effect of catalyst ratio on the dehydration reaction was investigated.

4 is a graph showing yields of AMF and HMF according to Examples 5-2, 5-8 to 5-11. Referring to Figure 4, while maintaining the composition of the reaction medium as a mixture of 15% DMSO in 1,4-dioxane and varying the mass ratio between the catalyst/substrate, the AMF yield was greater than 50% when the catalyst/substrate ratio (R) ranged from 0.6 to 1.0 (w/w), and the formation of AMF was significantly improved and stabilized compared to using a lower catalyst/substrate mass ratio. This means that when optimizing the procedure for sustainable production, the amount of catalyst can be adjusted slightly to lower the cost of the reaction.

Test Example 8: Analysis of scale-up results for AMF production

The amount of DAF used, the DAF conversion rate, the AMF yield and the HMF yield of Examples 6-1 to 6-5 are shown in Table 6 below.

DAF (g) scale up DAF Conversion Rate (%) AMF yield (%) HMF yield (%) Example 6-1 0.5 ×10 69.9 54.7 9.8 Example 6-2 1.0 ×20 71.2 54.2 11.2 Example 6-3 2.0 ×40 73.8 56.1 13.7 Example 6-4 4.0 ×80 74.7 55.4 15.5 Example 6-5 5.0 ×100 74.9 57.9 15.8

Referring to Table 6, it was confirmed that it can be effectively scaled up to 100 times without affecting the yield of the desired AMF product. Since the amount of DAF and Amberlyst 15 was increased while keeping the amount of solvent at a constant value, the stirring speed had to be slightly adjusted (range 300 to 500 rpm) for better thermal control during the whole reaction process.

Test Example 8: Yield of AMF and HMF according to the number of reuses of Amberlyst 15

5 is a graph showing AMF and HMF yields according to the number of reuses of Amberlyst 15 of Example 7. Referring to FIG. 5, it was confirmed that Amberlyst 15 could be reused up to 5 cycles without significant change in the yield of AMF and HMF.

Although the preferred embodiments of the present invention have been described above, those skilled in the art will be able to variously modify and change the present invention by adding, changing, deleting or adding elements within the scope not departing from the spirit of the present invention described in the claims, and this will also be said to be included within the scope of the present invention. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form. The scope of the present invention is indicated by the claims to be described later rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof should be construed as being included in the scope of the present invention.

Claims (16)

As in Scheme 1,
(a) preparing compound 2 by trans-esterification of compound 1, D-fructose, with an acyl donor in the presence of an immobilized enzyme; and
(b) preparing compound 3, 5-acyloxymethyl-2-furfural, by dehydrating compound 2 in the presence of a solid acid catalyst;
Method for producing 5-acyloxymethyl-2-furfural containing:
[Scheme 1]

In Scheme 1 above,
R ¹ is a C1 to C3 alkyl group. According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the acyl donor is a compound represented by Formula 4 below:
[Formula 4]

In Formula 4,
R ¹ is a C1 to C3 alkyl group;
R ² is a C1 to C3 alkyl group, or ego,
R ³ is a hydrogen atom or a C1 to C3 alkyl group. According to claim 2,
In Formula 4,
R ¹ is a methyl group;
compound 2 is 1,6-diacetylfructose (DAF);
A method for producing 5-acyloxymethyl-2-furfural, characterized in that compound 3 is 5-acetoxymethyl-2-furfural (AMF). According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the immobilized enzyme is lipase. According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the immobilized enzyme is not used or is filtered and recycled after being used as a catalyst for the trans-esterification reaction. According to claim 1,
Step (a) is carried out as a solution reaction using a solvent;
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the solvent in step (a) includes at least one selected from the group consisting of water, methanol, ethanol, acetone, tetrahydrofuran, 1,4-dioxane, dimethylsulfoxide, ethyl acetate, methyl isobutyl ketone, hexane, and dichloromethane. According to claim 6,
A method for preparing 5-acyloxymethyl-2-furfural, characterized in that the solvent in step (a) contains at least one selected from the group consisting of tetrahydrofuran and 1,4-dioxane. According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the solid acid catalyst comprises a cation exchange resin. According to claim 8,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the cation exchange resin comprises Amberlyst 15. According to claim 1,
Step (b) is carried out as a solution reaction using a solvent;
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the solvent in step (b) contains at least one selected from the group consisting of tetrahydrofuran, 1,4-dioxane and dimethylsulfoxide. According to claim 10,
The solvent of step (b) includes the 1,4-dioxane and the dimethyl sulfoxide,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that it comprises 10 to 100 parts by weight of the dimethyl sulfoxide based on 100 parts by weight of the 1,4-dioxane. According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the solid acid catalyst has a Bronsted acid or Lewis acid functional group connected to an organic support or an inorganic support. According to claim 1,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the solid acid catalyst is not used or recycled after being used as a catalyst for the dehydration reaction. According to claim 1,
The method for producing 5-acyloxymethyl-2-furfural, characterized in that the weight ratio of the solid acid catalyst to the compound 2 (solid acid catalyst / compound 2) in step (b) is 0.5 to 1. According to claim 14,
A method for producing 5-acyloxymethyl-2-furfural, characterized in that the immobilized enzyme and the solid acid catalyst are each independently immobilized on a carrier. delete