阅读说明：本技术 一种2,5-二甲酰基呋喃的制备方法 (Preparation method of 2, 5-diformylfuran ) 是由 徐杰 范晓萌 马继平 高进 高鸣霞 苗虹 于 2020-05-19 设计创作，主要内容包括：本申请公开了一种2,5-二甲酰基呋喃的制备方法,所述方法至少包括：以氧气或空气为氧化剂,将含有5-羟甲基糠醛的物料,在双组分催化体系和有机添加剂的存在下反应,制备得到2,5-二甲酰基呋喃。该方法是一种高收率、低成本、催化剂易分离、低污染、无溶剂的本体氧化新技术,以分子氧或空气为氧化剂,氧化5-羟甲基糠醛制备2,5-二甲酰基呋喃。该方法具有广阔的应用前景。(The application discloses a preparation method of 2, 5-diformylfuran, which at least comprises the following steps: oxygen or air is used as an oxidant, and a material containing 5-hydroxymethylfurfural reacts in the presence of a two-component catalytic system and an organic additive to prepare the 2, 5-diformylfuran. The method is a novel bulk oxidation technology with high yield, low cost, easy separation of catalyst, low pollution and no solvent, and uses molecular oxygen or air as an oxidant to oxidize 5-hydroxymethylfurfural to prepare 2, 5-diformylfuran. The method has wide application prospect.)

1. A process for the preparation of 2, 5-diformylfuran, characterized in that it comprises at least: reacting a material containing 5-hydroxymethylfurfural in the presence of a bi-component catalytic system and an organic additive by taking oxygen or air as an oxidant to prepare 2, 5-diformylfuran;

wherein the two-component catalytic system comprises a first component and a second component;

the first component is at least one of vanadium oxide compounds;

the second component is selected from at least one of nitrate;

the organic additive is at least one of nitrile compounds, carboxylic acid derivatives, 2-cyanopyridine compounds, 1, 4-dioxane, acetone, N-dimethylformamide and tetramethylurea;

the dosage of the organic additive is 0.1-150% of the molar weight of 5-hydroxymethylfurfural.

2. The method according to claim 1, wherein the vanadium-oxygen compound is at least one selected from vanadyl acetylacetonate, vanadyl sulfate, sodium metavanadate, vanadyl phosphate, vanadyl triethoxide, and vanadyl trichloride.

3. The production method according to claim 1, wherein the nitrate is at least one selected from the group consisting of a transition metal nitrate, a rare earth metal nitrate, and an alkali metal nitrate.

4. The production method according to claim 1, wherein the transition metal nitrate is at least one selected from the group consisting of copper nitrate, nickel nitrate, cobalt nitrate, iron nitrate, and zinc nitrate;

the alkali metal nitrate is selected from sodium nitrate;

the rare earth metal nitrate is selected from cerium nitrate.

5. The production method according to claim 1, characterized in that the nitrile compound is at least one selected from acetonitrile, hexanenitrile, dodecanonitrile, trimethylacetonitrile, succinonitrile, glutaronitrile, and adiponitrile;

the carboxylic acid is at least one of anhydrous formic acid and acetic acid;

the carboxylic acid derivative is selected from ethyl acetate;

the 2-cyanopyridine compound is selected from 2-cyanopyridine.

6. The preparation method according to claim 1, wherein the amount of the nitrate in the two-component catalytic system is 0.1-40% of the molar amount of 5-hydroxymethylfurfural;

wherein the molar amount of the nitrate is calculated by the molar amount of the metal in the nitrate.

7. The preparation method according to claim 1, wherein the amount of the vanadium oxide compound in the two-component catalytic system is 0.1-40% of the molar amount of 5-hydroxymethylfurfural;

wherein the molar amount of the vanadium-oxygen compound is calculated by the molar amount of the metal vanadium.

8. The method according to claim 1, wherein the reaction temperature is 50 to 200 ℃; the reaction time is 0.5-10 h; the oxygen partial pressure is 0.02-5.0 MPa.

9. The preparation method according to claim 8, wherein the reaction temperature is 60-150 ℃; the reaction time is 1-5 h; the oxygen partial pressure is 0.05-3.0 MPa.

10. The method of claim 1, further comprising a separation step after the reaction;

the separating at least comprises: and after the reaction is finished, adding an organic solvent, filtering, removing the organic solvent, and drying to obtain the 2, 5-diformylfuran.

Technical Field

The application relates to a preparation method of 2, 5-diformylfuran, belonging to the technical field of chemical synthesis.

Background

The renewable biomass resources are catalytically converted to prepare chemicals and liquid fuels with high added values, and the chemicals and the liquid fuels are used as the supplement of the traditional fossil resource synthesis route and are widely concerned. 2, 5-diformylfuran is one of the important oxidation products of 5-hydroxymethylfurfural, with the typical chemical properties of aldehydes. The 2, 5-diformylfuran can be used as a starting material of fine chemicals such as medicines, macrocyclic ligands, antifungal agents, nematocides, organic ligands and the like, can be used as a cross-linking agent of polyvinyl alcohol of a battery separator, a component of a sand binder for casting, organic fluorescent powder and a luminous body, is also an important monomer of a furan-based polymer, such as Schiff base synthesized by the 2, 5-diformylfuran and different diamines, and biomass-based novel resin synthesized by urea, and has high market value. Through literature research, no report on the preparation of 2, 5-diformylfuran by catalytic oxidation of 5-hydroxymethylfurfural under the solvent-free condition exists at present.

Disclosure of Invention

According to one aspect of the application, the method is a novel bulk oxidation technology with high yield, low cost, easy catalyst separation, low pollution and no solvent, and the method takes molecular oxygen or air as an oxidant to prepare the 2, 5-diformylfuran by catalytic oxidation of 5-hydroxymethylfurfural under the condition of no solvent. The method has wide application prospect.

In one aspect of the present application, there is provided a process for the preparation of 2, 5-diformylfuran, said process comprising at least: reacting a material containing 5-hydroxymethylfurfural in the presence of a bi-component catalytic system and an organic additive by taking oxygen or air as an oxidant to prepare 2, 5-diformylfuran;

wherein the two-component catalytic system comprises a first component and a second component;

the first component is at least one of vanadium oxide compounds;

the second component is selected from at least one of nitrate;

the organic additive is at least one of nitrile compounds, carboxylic acid derivatives, 2-cyanopyridine compounds, 1, 4-dioxane, acetone, N-dimethylformamide and tetramethylurea;

the dosage of the organic additive is 0.1-150% of the molar weight of 5-hydroxymethylfurfural.

Optionally, the amount of the organic additive used in the present application is 0.01 to 500. mu.L.

Optionally, the vanadium-oxygen compound is selected from at least one of vanadyl acetylacetonate, vanadyl sulfate, sodium metavanadate, vanadyl phosphate, vanadyl triethoxide, and vanadyl trichloride.

Optionally, the nitrate is selected from at least one of transition metal nitrate, rare earth metal nitrate, alkali metal nitrate.

Optionally, the transition metal nitrate is selected from at least one of copper nitrate, nickel nitrate, cobalt nitrate, ferric nitrate, and zinc nitrate;

the alkali metal nitrate is selected from sodium nitrate;

the rare earth metal nitrate is selected from cerium nitrate.

Optionally, the nitrile compound is selected from at least one of acetonitrile, hexanenitrile, dodecanonitrile, trimethylacetonitrile, succinonitrile, glutaronitrile, adiponitrile;

the carboxylic acid is at least one of anhydrous formic acid and acetic acid;

the carboxylic acid derivative is selected from ethyl acetate;

the 2-cyanopyridine compound is selected from 2-cyanopyridine.

Optionally, the amount of the nitrate in the bi-component catalytic system is 0.1-40% of the molar weight of 5-hydroxymethylfurfural;

wherein the molar amount of the nitrate is calculated by the molar amount of the metal in the nitrate.

Optionally, the amount of nitrate used in the two-component catalytic system is such that the upper limit of the molar amount of 5-hydroxymethylfurfural is independently selected from 0.3%, 0.5%, 0.6%, 0.8%, 1%, 2%, 3%, 4%, 6%, 8%, 9%, 10%, 12%, 15%, 16%, 19%, 20%, 21%, 23%, 25%, 27%, 30%, 32%, 35%, 36%, 40%; the lower limit is independently selected from 0.1%, 0.3%, 0.5%, 0.6%, 0.8%, 1%, 2%, 3%, 4%, 6%, 8%, 9%, 10%, 12%, 15%, 16%, 19%, 20%, 21%, 23%, 25%, 27%, 30%, 32%, 35%, 36%.

Optionally, the amount of the vanadium oxide compound in the bi-component catalytic system is 0.1-40% of the molar weight of 5-hydroxymethylfurfural;

wherein the molar amount of the vanadium-oxygen compound is calculated by the molar amount of the metal vanadium.

Optionally, the amount of vanadium oxide compound used in the two-component catalytic system is such that the upper limit of the molar amount of 5-hydroxymethylfurfural is independently selected from 0.3%, 0.4%, 0.6%, 1%, 1.5%, 3%, 5%, 6%, 7%, 9%, 10%, 12%, 15%, 16%, 19%, 21%, 22%, 23%, 24%, 25%, 27%, 28%, 30%, 32%, 34%, 36%, 40%; the lower limit is independently selected from 0.1%, 0.3%, 0.4%, 0.6%, 1%, 1.5%, 3%, 5%, 6%, 7%, 9%, 10%, 12%, 15%, 16%, 19%, 21%, 22%, 23%, 24%, 25%, 27%, 28%, 30%, 32%, 34%, 36%.

Optionally, the reaction temperature is 50-200 ℃; the reaction time is 0.5-10 h; the oxygen partial pressure is 0.02-5.0 MPa.

Optionally, the reaction temperature is 60-150 ℃; the reaction time is 1-5 h; the oxygen partial pressure is 0.05-3.0 MPa.

Even more preferably, the oxygen partial pressure is 0.1 to 1.0 MPa; the reaction temperature is 70-100 ℃; the reaction time is 1-3 h.

Alternatively, the upper limit of the oxygen partial pressure is independently selected from 0.05MPa, 0.1MPa, 0.5MPa, 1.0MPa, 1.4MPa, 1.7MPa, 2.3MPa, 2.6MPa, 2.9MPa, 3.1MPa, 3.5MPa, 3.8MPa, 4.2MPa, 4.7MPa, 5.0 MPa; the lower limits are independently selected from 0.02MPa, 0.05MPa, 0.1MPa, 0.3MPa, 0.7MPa, 1.1MPa, 1.5MPa, 1.8MPa, 2.2MPa, 2.6MPa, 3.1MPa, 3.6MPa, 4.0MPa, 4.5MPa, 4.8 MPa.

Optionally, the upper limit of the reaction temperature is independently selected from 55 ℃, 65 ℃, 75 ℃, 85 ℃, 95 ℃, 110 ℃, 125 ℃, 140 ℃, 155 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃; the lower limit is independently selected from 50 deg.C, 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 105 deg.C, 120 deg.C, 135 deg.C, 150 deg.C, 165 deg.C, 175 deg.C, 185 deg.C, 195 deg.C.

Alternatively, the upper limit of the reaction time is independently selected from 1h, 2h, 3h, 6h, 8h, 10 h; the lower limit is independently selected from 0.5h, 1.5h, 2.5h, 5h, 7h, 9 h.

Optionally, the organic additive is used in an amount of 0.1-150% of the molar amount of 5-hydroxymethylfurfural, and the addition amount is 0.01-500 μ L.

Optionally, the upper limit of the amount of the organic additive is independently selected from 10 μ L, 25 μ L, 50 μ L, 60 μ L, 70 μ L, 80 μ L, 90 μ L, 100 μ L, 110 μ L, 125 μ L, 150 μ L, 175 μ L, 200 μ L, 250 μ L, 300 μ L, 350 μ L, 400 μ L, 500 μ L; the lower limit of the amount of the organic additive is independently selected from the group consisting of 5. mu.L, 20. mu.L, 45. mu.L, 55. mu.L, 65. mu.L, 75. mu.L, 85. mu.L, 95. mu.L, 105. mu.L, 120. mu.L, 140. mu.L, 160. mu.L, 180. mu.L, 230. mu.L, 280. mu.L, 330. mu.L, 380. mu.L, and 480. mu.L.

Optionally, a separation step is further included after the reaction;

the separating at least comprises: and after the reaction is finished, adding an organic solvent, filtering, removing the organic solvent, and drying to obtain the 2, 5-diformylfuran.

The invention provides a method for preparing 2, 5-diformylfuran by catalyzing 5-hydroxymethylfurfural oxidation, which takes nitrate and vanadium species as catalysts, adds a small amount of organic additive, utilizes molecular oxygen or air to oxidize 5-hydroxymethylfurfural into 2, 5-diformylfuran, has mild reaction conditions, does not use organic solvent, has small catalyst dosage, is easy to separate, has high product yield, and is simple and convenient to operate, green, economic and environment-friendly.

The method of the invention is shown as formula 1:

according to the route provided by the invention, the oxidation of hydroxymethyl of 5-hydroxymethylfurfural into formyl under the action of molecular oxygen is realized to generate 2, 5-diformylfuran.

Analyzing the process of preparing 2, 5-diformylfuran by oxidizing 5-hydroxymethylfurfural, it is known that nitrogen oxides generated by the hydrolysis of nitrate oxidize low-valence vanadium species into high-valence vanadium species, and the high-valence vanadium species oxidize 5-hydroxymethylfurfural into 2, 5-diformylfuran under the action of an organic additive.

The organic additive in this application can also be considered as part of the catalytic system, catalyzing the reaction.

Optionally, adding 5-hydroxymethylfurfural, a catalyst and an organic additive into a reaction kettle, mixing, heating to 50-200 ℃, controlling the oxygen partial pressure to be 0.02-5.0MPa and the reaction time to be 0.5-10h, supplementing oxygen in time when the pressure is reduced by half in the reaction process, and oxidizing the 5-hydroxymethylfurfural into 2, 5-diformylfuran.

Optionally, after the obtaining of the 2, 5-diformylfuran, isolating the 2, 5-diformylfuran is further included. The step of isolating the 2, 5-diformylfuran comprises: after the reaction is finished, adding an organic solvent to dissolve the mixture after the reaction, filtering to remove the catalyst, removing the solvent by rotary evaporation, and drying to obtain a white solid, namely the 2, 5-diformylfuran.

Specifically, according to the method provided by the invention, the separation method of the oxidation product comprises the steps of cooling the mixture to room temperature by water after the reaction is finished, adding acetonitrile to dissolve the reacted mixture, filtering to remove the catalyst, removing the solvent by rotary evaporation, adding ethyl acetate, carrying out vacuum filtration, removing the solvent by rotary evaporation of the obtained filtrate, and drying to obtain a white solid.

In the reaction process of the preparation method, when the pressure is reduced by more than half, oxygen needs to be supplemented in time.

The beneficial effects that this application can produce include:

1) the invention realizes the preparation of 2, 5-diformylfuran by catalytic oxidation of 5-hydroxymethylfurfural under the solvent-free condition for the first time.

2) The catalyst system has high activity, good product selectivity, low consumption, low cost, easy obtaining, environmental protection and economy.

3) The method has mild reaction conditions, less catalyst consumption, easy separation from a reaction system after reaction, high quality of separated and purified products, and purity of the separated products reaching more than 99 percent through test analysis of gas chromatography-mass spectrometry, nuclear magnetic resonance spectrometer and the like and comparison with retention time of a standard sample.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.

According to the method for preparing 2, 5-diformyl furan by catalytic oxidation of 5-hydroxymethylfurfural, nitrate and vanadium species are used as catalysts, molecular oxygen or air is used as an oxidant, a small amount of organic additive is added, 5-hydroxymethylfurfural is oxidized, and a product is separated to obtain the 2, 5-diformyl furan.

In the application, the separation method of the oxidation product comprises the steps of cooling the mixture to room temperature by water after the reaction is finished, adding acetonitrile to dissolve the reacted mixture, filtering to remove the catalyst, removing the solvent by rotary evaporation, adding ethyl acetate, carrying out vacuum filtration, removing the solvent by rotary evaporation of the obtained filtrate, and drying to obtain a white solid.

In the specific operation, the organic additive, nitrate and vanadium species and 5-hydroxymethylfurfural are placed into a reaction kettle, the temperature is increased to 50-200 ℃, the oxygen partial pressure is 0.02-5.0MPa, the reaction time is 0.5-10h, and the 5-hydroxymethylfurfural is oxidized into 2, 5-diformylfuran.

In the present application, the oxygen partial pressure is preferably 0.05 to 3.0MPa, most preferably 0.1 to 1.0 MPa; the reaction temperature is preferably 60-150 ℃, and most preferably 70-100 ℃; the reaction time is preferably 1 to 5 hours, most preferably 1 to 3 hours.

The invention provides a method for preparing 2, 5-diformylfuran by catalyzing 5-hydroxymethylfurfural to be oxidized under the solvent-free condition, which takes molecular oxygen or air as an oxidant, takes nitrate and vanadium species as catalysts, and adds a small amount of organic additive to oxidize 5-hydroxymethylfurfural into 2, 5-diformylfuran. The 2, 5-diformylfuran prepared by the method has high purity, does not add an organic solvent, and is green and environment-friendly.

The conversion, selectivity, and separation in the examples of the present application were calculated as follows (the amounts in the following are amounts of substances):

the gas chromatograph in the embodiment of the application is Agilent 7890A.

Example 1:

adding 10mmol of 5-hydroxymethylfurfural and 0.2mmol of Cu (NO)₃)₂，0.15mmol VOSO₄Adding 150 mu L of acetonitrile into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.1MPa of oxygen, heating to 80 ℃, reacting for 0.5h at the temperature, and supplementing oxygen to 0.1MPa in time when the pressure is reduced by half in the reaction process. After the reaction was completed, the reacted mixture was cooled to room temperature with water, acetonitrile was added to dissolve the solid, and then the catalyst was removed by filtration. Adding the internal standard mesitylene, sampling and carrying out gas chromatography analysis. Removing acetonitrile by rotary evaporation, adding ethyl acetate, vacuum-filtering, removing ethyl acetate by rotary evaporation, and vacuum-drying to obtain white solid with Gas Chromatography (GC) purity of more than 99%.

The conversion of 5-hydroxymethylfurfural, the GC yield of 2, 5-diformylfuran and the separation yield of 2, 5-diformylfuran were calculated, respectively. The conversion of 5-hydroxymethylfurfural was 87%, the GC yield of 2, 5-diformylfuran was 86%, and the isolation yield of 2, 5-diformylfuran was 85%.

Example 2

Adding 10mmol of 5-hydroxymethyl furfural and 0.01mmol of Ni (NO)₃)₂，0.01mmol NaVO₃Adding 400 mu L of hexanenitrile into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 5.0MPa oxygen, heating to 50 ℃, reacting for 1h at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 90%, the GC yield of 2, 5-diformylfuran was 88%, and the isolation yield was 87%.

Example 3

Will be 10mmol 5-hydroxymethylfurfural, 0.05mmol Co (NO)₃)₂，0.04mmol VOPO₄200 mu L of dodecanonitrile is added into a 50mL reaction kettle, the kettle is closed, the air in the kettle is replaced by oxygen for 7 times, 3.0MPa of oxygen is filled, the temperature is raised to 60 ℃, the reaction is carried out for 1.5 hours at the temperature, and the oxygen is supplemented in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 85%, the GC yield of 2, 5-diformylfuran was 84%, and the isolation yield was 83%.

Example 4

Adding 10mmol of 5-hydroxymethylfurfural and 0.08mmol of Ce (NO)₃)₃，0.06mmol VO(OEt)₃Adding 10 mu L of glutaronitrile into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.02MPa of oxygen, heating to 200 ℃, reacting for 2 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 89%, the GC yield of 2, 5-diformylfuran was 88%, and the isolation yield was 87%.

Example 5

Adding 10mmol of 5-hydroxymethylfurfural and 0.1mmol of NaNO₃，0.3mmol VO(acac)₂150 mu L of adiponitrile is added into a 50mL reaction kettle, the kettle is closed, the air in the kettle is replaced by oxygen for 7 times, 1.0MPa of oxygen is filled, the temperature is increased to 70 ℃, the reaction is carried out for 2.5 hours at the temperature, and the oxygen is supplemented in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 88%, the GC yield of 2, 5-diformylfuran was 87%, and the isolation yield was 86%.

Example 6

Adding 10mmol of 5-hydroxymethyl furfural and 0.4mmol of Fe (NO)₃)₃，0.5mmol VOCl₃300 mu L of trimethyl acetonitrile is added into a 50mL reaction kettle, the kettle is closed, the air in the kettle is replaced by oxygen for 7 times, 0.8MPa of oxygen is filled, the temperature is increased to 80 ℃, the reaction is carried out for 3 hours at the temperature, and the oxygen is supplemented in time when the pressure is reduced by half in the reaction process. After the reaction was complete, the procedure of example 1 was followedThe conversion of 5-hydroxymethylfurfural was 88%, the GC yield of 2, 5-diformylfuran was 87% and the isolation yield was 86% by cooling and sampling analysis.

Example 7

Adding 10mmol of 5-hydroxymethyl furfural and 0.6mmol of Zn (NO)₃)₂，0.7mmol VOSO₄50 mu L N, adding N-dimethylformamide into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.05MPa oxygen, heating to 150 ℃, reacting for 3.5 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 98%, the GC yield of 2, 5-diformylfuran was 97%, and the isolation yield was 96%.

Example 8

Adding 10mmol of 5-hydroxymethylfurfural and 0.8mmol of Cu (NO)₃)₂，1mmol NaVO₃500 mu L of 2-cyanopyridine is added into a 50mL reaction kettle, the kettle is closed, the air in the kettle is replaced by oxygen for 7 times, 0.5MPa of oxygen is filled, the temperature is increased to 90 ℃, the reaction is carried out for 4 hours at the temperature, and the oxygen is supplemented in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 91%, the GC yield of 2, 5-diformylfuran was 90%, and the isolation yield was 89%.

Example 9

Adding 10mmol of 5-hydroxymethyl furfural and 1mmol of Ni (NO)₃)₂，1.2mmol VOPO₄Adding 100 mu L of anhydrous formic acid into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.1MPa of oxygen, heating to 100 ℃, reacting for 4.5 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 85%, the GC yield of 2, 5-diformylfuran was 84%, and the isolation yield was 83%.

Example 10

Adding 10mmol of 5-hydroxymethylfurfural and 1.5mmol of Co (NO)₃)₂，1.6mmol VO(OEt)₃，1Adding 50 mu L of acetic acid into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.2MPa of oxygen, heating to 100 ℃, reacting for 5 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 94%, the GC yield of 2, 5-diformylfuran was 93%, and the isolation yield was 92%.

Example 11

Adding 10mmol of 5-hydroxymethylfurfural and 2mmol of Ce (NO)₃)₃，2.2mmol VO(acac)₂Adding 250 mu L of ethyl acetate into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.1MPa of oxygen, heating to 90 ℃, reacting for 6 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 93%, the GC yield of 2, 5-diformylfuran was 92%, and the isolation yield was 91%.

Example 12

Adding 10mmol of 5-hydroxymethylfurfural and 2.5mmol of NaNO₃，2.4mmol VOCl₃350 mu L of 1, 4-dioxane is added into a 50mL reaction kettle, the kettle is closed, the air in the kettle is replaced by oxygen for 7 times, 0.3MPa of oxygen is filled, the temperature is increased to 80 ℃, the reaction is carried out for 7 hours at the temperature, and the oxygen is supplemented in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 92%, the GC yield of 2, 5-diformylfuran was 91%, and the isolation yield was 90%.

Example 13

Adding 10mmol of 5-hydroxymethyl furfural and 3mmol of Fe (NO)₃)₃，2.8mmol VOSO₄Adding 75 mu L of acetone into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.1MPa of oxygen, heating to 80 ℃, reacting for 8 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction was completed, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 95%, and the GC yield of 2, 5-diformylfuran was found to be94% and the isolation yield 93%.

Example 14

Adding 10mmol of 5-hydroxymethylfurfural and 3.5mmol of Zn (NO)₃)₂，3.4mmol NaVO₃Adding 25 mul of tetramethylurea into a 50mL reaction kettle, closing the kettle, replacing the air in the kettle with oxygen for 7 times, filling 0.4MPa of oxygen, heating to 85 ℃, reacting for 9 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 90%, the GC yield of 2, 5-diformylfuran was 89%, and the isolation yield was 88%.

Example 15

Adding 10mmol of 5-hydroxymethylfurfural and 4mmol of Cu (NO)₃)₂，4mmol VOPO₄Adding 450 mu L of succinonitrile into a 50mL reaction kettle, closing the kettle, replacing air in the kettle with oxygen for 7 times, filling 0.6MPa of oxygen, heating to 80 ℃, reacting for 10 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 95%, the GC yield of 2, 5-diformylfuran was 94%, and the isolation yield was 93%.

Example 16

Adding 10mmol of 5-hydroxymethylfurfural and 0.2mmol of Cu (NO)₃)₂，0.2mmol VOSO₄Adding 250 mu L of acetonitrile into a 50mL reaction kettle, closing the kettle, replacing the air in the kettle with air for 7 times, filling 4Mpa of air, heating to 80 ℃, reacting for 10 hours at the temperature, and supplementing oxygen in time when the pressure is reduced by half in the reaction process. After the reaction, according to the method described in example 1, cooling and sampling analysis, the conversion of 5-hydroxymethylfurfural was 85%, the GC yield of 2, 5-diformylfuran was 84%, and the isolation yield was 83%.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.