Preparation method of 2-furanone acid
Through the reaction of furfural with sodium bisulfite and cyanide, combined with acidic hydrolysis and oxidation catalysis, the problems of excessive use of oxidants and multiple side reactions in the prior art have been successfully solved, achieving efficient and safe preparation of 2-furanjejunic acid , improves yield and production efficiency, while reducing the risk of environmental pollution.
Patent Information
- Application Number
- CN202411256916.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-13
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the preparation of 2-furanjejunic acid, the prior art has problems such as the use of a large number of oxidants, the number of side reactions, the yield is low, the oxidation reaction conditions are harsh, and the raw materials are toxic and environmental pollution risks.
Furfural reaction with sodium bisulfite is used to form the sodium bisulfite adduct of furfural, then react with cyanide to form α-hydroxyfuranacetonitrile, and hydrolyze under acidic conditions, and finally oxidize to 2-furanone acid under oxidation catalytic system. , avoiding the use of oxidants, simplifying the synthesis route, and improving yield and safety.
It realizes efficient and safe preparation of 2-furanjejunic acid, reduces the safety risks of oxidizing agent use, improves synthesis efficiency and yield, reduces raw material consumption and production costs, and is environmentally friendly.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of pharmaceutical chemistry, and specifically relates to a method for preparing 2-furanone acid. Background Art
[0002] As a new type of β-lactam antibiotic with high efficiency and low toxicity, cephalosporin antibiotics are the fastest-growing and most innovative antibiotics in recent years. There are dozens of varieties used in clinical applications. Cefuroxime sodium or cefuroxime axetil is a second-generation cephalosporin developed by GlaxoSmithKline in the UK. It has the characteristics of a broad antibacterial spectrum and a wide range of applications. It can be used for respiratory tract infections, urinary tract infections, skin and soft tissue infections caused by sensitive bacteria. It is a cephalosporin antibiotic with a good development momentum in recent years. Cefuroxime sodium has been ranked among the top in the world pharmaceutical sales rankings for several consecutive years, with a huge consumer market and good development prospects. (Z)-2-methoxyimino-2-furanacetic acid ammonium salt (furan ammonium salt) is an important intermediate for the production of cefuroxime sodium and cefuroxime axetil, and furanone acid (2-oxo-2-furanacetic acid) is a key intermediate for the synthesis of furan ammonium salt.
[0003] The structural formula of furanone acid (2-oxo-2-furanacetic acid), a key intermediate of cefuroxime, is as follows:
[0004]
[0005] Currently, there are several main methods for synthesizing furanone acid.
[0006] Chinese patent CN102010390A discloses a method for preparing furan ammonium salt using furan carboxylic acid, wherein furoic acid is used as a raw material, chlorinated with thionyl chloride to obtain 2-acetylcarbonyl chloride, then cyanated with sodium cyanide or potassium cyanide, and finally hydrolyzed under acidic conditions to obtain the product. The method has a long route, and a large amount of hydrogen chloride and sulfur dioxide gas are generated during the chlorination process. The raw materials sodium cyanide or potassium cyanide used are highly toxic and will cause great harm to the environment and human body.
[0007] Chinese patent CN102863407A discloses a method of using acetofuran as a raw material and using sodium nitrite to oxidize under strong acid conditions. This method obtains furanone acid in one step, has a short route, and the raw materials are cheap and easy to obtain, and have low toxicity. It is more suitable for industrialization. However, this oxidation method uses a large amount of oxidant, and there is a problem of deep oxidation that causes a low yield and a safety risk.
[0008] Chinese patent CN115504947B discloses a method for preparing furanolic acid, which uses sulphuraldehyde as a starting material and nitromethane under base catalysis to generate β-nitro alcohol, and β-nitro alcohol is oxidized in one step by a TEMPO / O2 catalytic oxidation system using air or oxygen as an oxidant to synthesize furanolic acid. This method uses a large amount of nitromethane, is flammable and explosive, has harsh oxidation reaction conditions, poor reproducibility, and does not have industrial production value.
[0009] At present, there are many problems in the preparation of furanone acid using 2-acetylfuran as a raw material, such as many side reactions, low yield, and large amount of oxidant used. Summary of the invention
[0010] The object of the present invention is to provide a novel method for preparing 2-furanone acid.
[0011] In some embodiments, a method for preparing 2-furanone acid of the present invention comprises the following steps:
[0012] 1) reacting furfural (II) with sodium bisulfite in a solvent to generate furfural sodium bisulfite adduct (III);
[0013] 2) reacting furfural sodium bisulfite adduct (III) with cyanide in an organic solvent to generate α-hydroxyfuranacetonitrile (IV);
[0014] 3) hydrolyzing α-hydroxyfuranacetonitrile (IV) under acidic conditions to generate α-hydroxyfuranacetic acid (V);
[0015] 4) oxidizing α-hydroxyfuranacetic acid (V) to 2-furanone acid (I) in an organic solvent under an oxidation catalyst system.
[0016] The preparation method of the present invention described above, the synthesis route is as follows:
[0017]
[0018]
[0019] Preferably, in the preparation method of the present invention, the solvent in step 1) is selected from one or more of water, ethanol and methanol, wherein the molar ratio of furfural to sodium bisulfite is 1:(0.8-1.2). The reaction temperature in step 1) is 0-50°C.
[0020] Preferably, in the preparation method of the present invention, in step 2), the organic solvent is a non-protonic polar solvent, preferably acetonitrile or DMF, and the pH of the reaction system is adjusted to 7-8 with a base, and the base is a sodium hydroxide solution or a potassium hydroxide solution.
[0021] Preferably, in the preparation method of the present invention, in step 2), the molar ratio of furfural sodium bisulfite adduct to cyanide is 1: (1.2-2.0), and the cyanide is selected from sodium cyanide, potassium cyanide and cuprous cyanide, preferably sodium cyanide or potassium cyanide. Wherein, the reaction temperature of step 2) is 0-50°C, preferably 20-40°C.
[0022] Preferably, in the preparation method of the present invention, in step 3), the acid is concentrated hydrochloric acid, and further comprises a reaction solvent, which is preferably a mixed solvent of water and ethanol, more preferably a volume ratio of water to ethanol of 1:1, and a molar ratio of α-hydroxyfuranacetonitrile to hydrochloric acid of 1:(1-2). Wherein, the reaction temperature of step 3) is 10-50°C, preferably 30°C, and the reaction time is 4-12 hours, preferably 7 hours.
[0023] Preferably, in the above-mentioned preparation method of the present invention, in step 4), the organic solvent is ethylene dichloride.
[0024] Preferably, in the preparation method of the present invention, in step 4), the oxidation catalytic system is selected from: a) comprising a catalyst TEMPO, a co-catalyst Fe(NO 3 ) 3 9H 2 O and KCl and the oxygen source is air or oxygen, and b) contains the oxidizing agent potassium permanganate.
[0025] Preferably, in the preparation method of the present invention, in step 4), α-hydroxyfuranacetic acid: TEMPO: Fe(NO 3 ) 3 9H 2 The molar ratio of O: KCl is 1: 0.1: 0.1: 0.1. The molar ratio of α-hydroxyfuranacetic acid: potassium permanganate is 1: 1.2-1.5. The reaction temperature of step 4) is 10-40° C., preferably 20-30° C., and the reaction time is 7-48 hours, preferably 18-24 hours.
[0026] The preparation method of the present invention has the advantages that: no oxidant is used to oxidize furfural to furoic acid, the safety risk of using the oxidant is reduced, and no large amount of impurities are generated due to the oxidant as in the prior art. The preparation method of the present invention has a high yield, can greatly improve the synthesis efficiency of organic compounds, reduce the reaction time and the consumption of raw materials, and reduce the production cost; at the same time, the preparation method of the present invention does not need to use a large amount of organic solvents, and is more environmentally friendly. DETAILED DESCRIPTION
[0027] The following examples are representative and are used to further understand and illustrate the essence of the present invention. Therefore, they cannot be used to limit the scope of the present invention. Any simple modifications and adaptations within the scope of the present invention also belong to the scope of the present invention.
[0028] Example 1 Preparation of 2-furanone acid
[0029] Step 1: Add 50 grams of ethanol and 9.61 grams (0.1 mol) of furfural into a three-necked flask and stir to dissolve, then slowly add 10.41 grams (0.1 mol) of sodium bisulfite. Control the temperature at 25-30 degrees Celsius, and slowly add 10 grams of water. Stir for half an hour to produce a large amount of white solid. Filter by suction, wash the filter cake with a small amount of ethanol, drain, and place in a hot air drying oven at 60 degrees to dry for one hour. Collect 16.5 grams of material, with a yield of 82.5%.
[0030] Step 2: 30 g of acetonitrile, 10 g of furfural sodium bisulfite adduct (0.05 mol) of step 1, and 2.94 g of sodium cyanide (0.06 mol) are stirred and adjusted to pH 7-8 with dilute sodium hydroxide solution. The mixture is heated to 80°C and refluxed for 1-4 hours, and the reaction is complete by HPLC. After the reaction is complete, 50 ml of water is added, and the mixture is extracted twice with 50 ml of ethyl acetate, and the organic phase is washed once with saturated brine. The organic phase is placed in a rotary distillation until no liquid flows out, and 5.16 g of a yellow transparent liquid is obtained, with a yield of 84.0%.
[0031] Step 3: Pour 12.3 g (0.1 mol) of α-furan cyanocyanide, 0.14 mol of concentrated hydrochloric acid, and a mixed solution of 20 mL of ethanol and water (volume ratio 1:1) into a 250 mL three-necked bottle and stir. React at 5°C for about 7 hours, and the reaction solution is a red clear liquid. After the reaction is completed, slowly add concentrated hydrochloric acid solution to the reaction solution in the bottle under an ice bath, stir vigorously, and adjust the pH value to about 1. A large amount of precipitation appears in the reaction solution. Wash with ice water to obtain a yellow solid, dry it, and recrystallize it with isopropanol to obtain 10.22 grams of white solid, with a yield of 71.91%.
[0032] Step 4: Take 14.29 (0.1 mol) α-furan glycolic acid, 150 ml 1,2-dichloroethane, 0.01 mol Tempo, 0.01 mol KCl, 0.01 mol Fe(NO 3 ) 3 9H 2O Use a booster pump to introduce air below the liquid level, react at 25-30°C for 10-24 hours, and monitor the reaction progress with HPLC. Adjust the pH to 10 with sodium hydroxide solution, add 100 ml of water, stir and separate the liquids, back-extract the organic phase with 50 ml of water once, and combine the two aqueous phases. Add 2 grams of sodium bisulfite and stir, add ethyl acetate, and adjust the pH to 1-2 with hydrochloric acid and stir and extract the liquids. Extract the liquids with 50 ml of ethyl acetate again, and combine the organic phases. Wash the organic phase with water again. Evaporate the solvent in the extract to obtain the crude product of Ⅱ-furanacetic acid. The crude product is recrystallized from toluene to obtain 10.01 grams of white crystals, which is 2-furanacetic acid, with a yield of 71%.
[0033] Example 2 Preparation of 2-furanone acid
[0034] Step 1: Add 50 grams of methanol and 9.61 grams (0.1 mol) of furfural into a three-necked flask and stir to dissolve, then slowly add 8.33 grams (0.08 mol) of sodium bisulfite. Control the temperature at 25-30 degrees Celsius, and slowly add 10 grams of water. Stir for half an hour to produce a large amount of white solid. Filter by suction, wash the filter cake with a small amount of ethanol, drain, and place in a hot air drying oven at 60 degrees to dry for one hour. Collect 16.2 grams of material, with a yield of 81%.
[0035] Step 2: 30 g of acetonitrile, 10 g of sodium bisulfite adduct of furfural in step 1 (0.05 mol), 3.91 g of potassium cyanide (0.06 mol), and adjust the pH to 7-8 with dilute sodium hydroxide solution under stirring. Heat to 80°C and reflux for 1-4 hours, and use HPLC to detect the complete reaction. After the reaction is complete, add 50 ml of water, extract twice with 50 ml of ethyl acetate, and wash the organic phase once with saturated brine. The organic phase is placed in a rotary distillation until no liquid flows out, and 4.92 g of yellow transparent liquid is obtained, with a yield of 80%.
[0036] Step 3: Pour 12.3 g (0.1 mol) of α-furan hydroxyacetonitrile, 0.10 mol of concentrated hydrochloric acid, and a mixed solution of 20 mL of ethanol and water (volume ratio 1:1) into a 250 mL three-necked bottle and stir. React at 5°C for about 7 hours, and the reaction solution is a red clear liquid. After the reaction is completed, slowly add concentrated hydrochloric acid solution to the reaction solution in the bottle under an ice bath, stir vigorously, and adjust the pH value to about 1. A large amount of precipitation appears in the reaction solution. Wash with ice water to obtain a yellow solid, dry it, and recrystallize it with isopropanol to obtain 8.9 grams of white solid, with a yield of 62.6%.
[0037] Step 4, take 14.29 (0.1 mol) α-furan glycolic acid, dissolve in 0.16 mol sodium hydroxide solution with a concentration of 10%, stir, and keep the reaction temperature at about 0 ° C. Slowly add 20.59 (0.13 mol) potassium permanganate under stirring and react for 20 minutes, and a large amount of brown-black manganese dioxide precipitates appear in the bottle. Then remove the excess potassium permanganate with ethanol, and slowly add 2 mol / L sodium hydroxide solution to adjust the pH value to 10. Filter and wash the filter cake with distilled water. Combine the filtrate, adjust the pH value to 2 with 5 mol / L hydrochloric acid under stirring, and extract three times with 30mL dichloromethane. Evaporate the solvent in the extract to obtain a crude product of 2-furanacetic acid. The crude product is recrystallized from toluene to obtain 6.44 grams of white crystals, i.e. 2-furanacetic acid, with a yield of 46%.
[0038] Example 3 Preparation of 2-furanone acid
[0039] Step 1: Add 50 grams of ethanol and 9.61 grams (0.1 mol) of furfural into a three-necked flask and stir to dissolve, then slowly add 12.49 grams (0.12 mol) of sodium bisulfite. Control the temperature at 25-30 degrees Celsius, and slowly add 10 grams of water. Stir for half an hour to produce a large amount of white solid. Filter by suction, wash the filter cake with a small amount of ethanol, drain, and place in a hot air drying oven at 60 degrees to dry for one hour. Collect 17.5 grams of material, with a yield of 87.5%.
[0040] Step 2: 30 g of acetonitrile, 10 g of sodium bisulfite adduct of furfural in step 1 (0.05 mol), 8.96 g of cuprous cyanide (0.1 mol), and stirring with dilute sodium hydroxide solution to adjust the pH to 7-8. Heat to 80°C and reflux for 1-4 hours, and detect the reaction by HPLC. After the reaction, add 50 ml of water, filter and extract the filtrate twice with 50 ml of ethyl acetate, and wash the organic phase once with saturated brine. The organic phase is placed in rotary distillation until no liquid flows out, and 3.67 g of yellow transparent liquid is obtained, with a yield of 59.6%.
[0041] Step 3: Pour 12.3 g (0.1 mol) of α-furan cyanocyanide, 0.12 mol of concentrated hydrochloric acid, and a mixed solution of 20 mL of ethanol and water (volume ratio 1:1) into a 250 mL three-necked bottle and stir. React at 5°C for about 7 hours, and the reaction solution is a red clear liquid. After the reaction is completed, slowly add concentrated hydrochloric acid solution to the reaction solution in the bottle under an ice bath, stir vigorously, and adjust the pH value to about 1. A large amount of precipitation appears in the reaction solution. Wash with ice water to obtain a yellow solid, dry it, and recrystallize it with isopropanol to obtain 9.4 grams of white solid, with a yield of 66.2%.
[0042] Step 4: Take 14.29 (0.1 mol) α-furan glycolic acid, 150 ml 1,2-dichloroethane, 0.01 mol Tempo, 0.01 mol KCl, 0.01 mol Fe(NO 3 ) 3 9H 2 O Use a booster pump to introduce air below the liquid level, react at 25-30°C for 10-24 hours, and monitor the reaction progress with HPLC. Adjust Ph=10 with sodium hydroxide solution, add 100 ml of water, stir and separate, back-extract the organic phase with 50 ml of water once, and combine the two aqueous phases. Add 2 grams of sodium bisulfite and stir, add ethyl acetate, and adjust the pH to 1-2 with hydrochloric acid and stir and extract the liquid. Extract the liquid with 50 ml of ethyl acetate again, and combine the organic phases. Wash the organic phase with water again. Evaporate the solvent in the extract to obtain the crude product of 2-furanacetic acid. Recrystallize the crude product with toluene to obtain 10.15 grams of white crystals, which is 2-furanacetic acid. The yield is 72.5%.
[0043] Example 4 Preparation of 2-furanone acid
[0044] Step 1: Add 50 grams of ethanol and 9.61 grams (0.1 mol) of furfural into a three-necked flask and stir to dissolve, then slowly add 12.49 grams (0.12 mol) of sodium bisulfite. Control the temperature at 25-30 degrees Celsius, and slowly add 10 grams of water. Stir for half an hour to produce a large amount of white solid. Filter by suction, wash the filter cake with a small amount of ethanol, drain, and place in a hot air drying oven at 60 degrees to dry for one hour, collecting 17.0 grams of material, with a yield of 85.0%.
[0045] Step 2: 30 g of acetonitrile, 10 g of furfural sodium bisulfite adduct (0.05 mol) of step 1, 3.67 g of sodium cyanide (0.075 mol), and stirring with dilute sodium hydroxide solution to adjust the pH to 7-8. Heat to 80 ° C and reflux for 1-4 hours, and use HPLC to detect the complete reaction. After the reaction is complete, add 50 ml of water, extract twice with 50 ml of ethyl acetate, and wash the organic phase once with saturated brine. The organic phase is placed in a rotary distillation until no liquid flows out, and 5.03 g of yellow transparent liquid is obtained, with a yield of 81.9%.
[0046] Step 3: Pour 12.3 g (0.1 mol) of α-furan cyanocyanide, 0.20 mol of concentrated hydrochloric acid, and a mixed solution of 20 mL of ethanol and water (volume ratio 1:1) into a 250 mL three-necked bottle and stir. React at 5°C for about 7 hours, and the reaction solution is a red clear liquid. After the reaction is completed, slowly add concentrated hydrochloric acid solution to the reaction solution in the bottle under an ice bath, stir vigorously, and adjust the pH value to about 1. A large amount of precipitation appears in the reaction solution. Wash with ice water to obtain a yellow solid, dry it, and recrystallize it with isopropanol to obtain 10.66 grams of white solid, with a yield of 75.1%.
[0047] Step 4: Take 14.29 (0.1 mol) α-furan glycolic acid, 150 ml 1,2-dichloroethane, 0.01 mol Tempo, 0.01 mol KCl, 0.01 mol Fe(NO 3 ) 3 9H 2 O Use a booster pump to introduce air below the liquid level, react at 25-30°C for 10-24 hours, and monitor the reaction progress with HPLC. Adjust the pH to 10 with sodium hydroxide solution, add 100 ml of water, stir and separate the liquids, back-extract the organic phase with 50 ml of water once, and combine the two aqueous phases. Add 2 grams of sodium bisulfite and stir, add ethyl acetate, and adjust the pH to 1-2 with hydrochloric acid and stir and extract the liquids. Extract the liquids with 50 ml of ethyl acetate again, and combine the organic phases. Wash the organic phase with water again. Evaporate the solvent in the extract to obtain the crude product of 2-furanacetic acid. The crude product is recrystallized from toluene to obtain 10.25 grams of white crystals, which is 2-furanacetic acid, with a yield of 73.2%.
[0048] Example 5 Preparation of 2-furanone acid
[0049] Step 1: Add 50 grams of ethanol and 9.61 grams (0.1 mol) of furfural into a three-necked flask and stir to dissolve, then slowly add 12.49 grams (0.12 mol) of sodium bisulfite. Control the temperature at 25-30 degrees Celsius, and slowly add 10 grams of water. Stir for half an hour to produce a large amount of white solid. Filter by suction, wash the filter cake with a small amount of ethanol, drain, and place in a hot air drying oven at 60 degrees to dry for one hour, collecting 16.6 grams of material, with a yield of 83.0%.
[0050] Step 2: 30 g of DMF, 10 g of sodium bisulfite adduct of furfural in step 1 (0.05 mol), 3.67 g of sodium cyanide (0.075 mol), and stirring with dilute sodium hydroxide solution to adjust the pH to 7-8. Heat to 80°C and reflux for 1-4 hours, and use HPLC to detect the complete reaction. After the reaction is complete, add 50 ml of water, extract twice with 50 ml of ethyl acetate, and wash the organic phase once with saturated brine. The organic phase is placed in a rotary distillation until no liquid flows out, and 4.89 g of yellow transparent liquid is obtained, with a yield of 79.4%.
[0051] Step 3: Pour 12.3 g (0.1 mol) of α-furan cyanocyanide, 0.20 mol of concentrated hydrochloric acid, and a mixed solution of 20 mL of ethanol and water (volume ratio 1:1) into a 250 mL three-necked bottle and stir. React at 5°C for about 7 hours, and the reaction solution is a red clear liquid. After the reaction is completed, slowly add concentrated hydrochloric acid solution to the reaction solution in the bottle under an ice bath, stir vigorously, and adjust the pH value to about 1. A large amount of precipitation appears in the reaction solution. Wash with ice water to obtain a yellow solid, dry it, and recrystallize it with isopropanol to obtain 10.2 grams of white solid, with a yield of 71.8%.
[0052] Step 4: Take 14.29 (0.1 mol) α-furan glycolic acid, 150 ml 1,2-dichloroethane, 0.01 mol Tempo, 0.01 mol KCl, 0.01 mol Fe(NO 3 ) 3 9H 2 O Use a booster pump to introduce air below the liquid level, react at 25-30°C for 10-24 hours, and monitor the reaction progress with HPLC. Adjust the pH to 10 with sodium hydroxide solution, add 100 ml of water, stir and separate the liquids, back-extract the organic phase with 50 ml of water once, and combine the two aqueous phases. Add 2 grams of sodium bisulfite and stir, add ethyl acetate, and adjust the pH to 1-2 with hydrochloric acid and stir and extract the liquids. Extract the liquids with 50 ml of ethyl acetate again, and combine the organic phases. Wash the organic phase with water again. Evaporate the solvent in the extract to obtain the crude product of 2-furanacetic acid. The crude product is recrystallized from toluene to obtain 9.88 grams of white crystals, which is 2-furanacetic acid, with a yield of 70.5%.
[0053] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.
Claims
1. A method for preparing 2-furanone acid, comprising the following steps: 1) reacting furfural (II) with sodium bisulfite in a solvent to generate furfural sodium bisulfite adduct (III); 2) reacting the furfural sodium bisulfite adduct (III) with cyanide in an organic solvent to generate α-hydroxyfuranacetonitrile (IV); 3) hydrolyzing α-hydroxyfuranacetonitrile (IV) under acidic conditions to generate α-hydroxyfuranacetic acid (V); 4) oxidizing α-hydroxyfuranacetic acid (V) to 2-furanone acid (I) in an organic solvent under an oxidation catalyst system.
2. The preparation method according to claim 1, wherein the solvent in step 1) is selected from one or more of water, ethanol and methanol.
3. The preparation method according to claim 1, wherein in step 1), the molar ratio of furfural to sodium bisulfite is 1:(0.8-1.2).
4. The preparation method according to claim 1, wherein in step 2), the organic solvent is an aprotic polar solvent, preferably acetonitrile or DMF.
5. The preparation method according to claim 1, wherein in step 2), the pH of the reaction system is adjusted to 7-8 with a base.
6. The preparation method according to claim 1, wherein in step 2), the molar ratio of furfural sodium bisulfite adduct to cyanide is 1:(1.2-2.0); wherein, The cyanide is selected from sodium cyanide, potassium cyanide and cuprous cyanide, preferably sodium cyanide or potassium cyanide.
7. The preparation method according to claim 1, wherein in step 3), the acid is concentrated hydrochloric acid, preferably, the molar ratio of α-hydroxyfuranacetonitrile to hydrochloric acid is 1:(1-2), and further comprising a reaction solvent, which is a mixed solvent of water and ethanol.
8. The preparation method according to claim 1, wherein in step 4), the organic solvent is ethylene dichloride.
9. The preparation method according to claim 1, in step 4), the oxidation catalytic system is selected from: a) comprising a catalyst TEMPO, a co-catalyst Fe(NO3)3·9H2O, KCl and an oxygen source air or oxygen, and b) comprising an oxidant potassium permanganate.
10. The preparation method according to claim 9, wherein the molar ratio of α-hydroxyfuranacetic acid:TEMPO:Fe(NO3)3·9H2O:KCl is 1:0.1:0.1:0.1; and the molar ratio of α-hydroxyfuranacetic acid:potassium permanganate is 1:1.2-1.5.