A method for preparing 5-hydroxymethyl-2-furanic acid

Abstract

This invention discloses a method for preparing 5-hydroxymethyl-2-furanic acid, comprising the following steps: first, adding HMF solution and catalyst to a round-bottom flask, then adding hydrogen peroxide dropwise, and stirring under normal pressure to efficiently and selectively oxidize HMF to 5-hydroxymethyl-2-furanic acid. The yield of 5-hydroxymethyl-2-furanic acid prepared reaches 94.30%. The entire reaction operation is simple and conducive to large-scale industrial production. Moreover, the raw material for preparing the catalyst in this invention is chitin, which is a biomass raw material of shrimp and crab shells, which is environmentally friendly and has low production cost. The obtained catalyst can be recycled multiple times, resulting in low production cost.

Description

Technical Field

[0001] This invention belongs to the field of organic chemical preparation technology, specifically relating to a method for preparing 5-hydroxymethyl-2-furanic acid. Background Technology

[0002] 5-Hydroxymethyl-2-furanic acid is an interleukin (J. Am. Chem. Soc., 2003, 125, 3714), and also possesses antitumor activity (Agric. Biol. Chem., 1981, 45, 2149). It has a promising market potential in medical treatment.

[0003] 5-Hydroxymethyl-2-furancarboxylic acid (HMFCA) is an intermediate product in the preparation of 2,5-furandicarboxylic acid from HMF. Biomass catalysts are used to prepare 5-hydroxymethyl-2-furancarboxylic acid, but the preparation process is difficult, time-consuming, and cannot be reused.

[0004] Chinese patent CN 110331174 A describes the preparation of 5-hydroxymethyl-2-furanic acid from agar, which falls under the field of biochemical engineering. However, the preparation of biomass catalysts is difficult and not easily reusable. Chinese patent CN112341415A discloses the photocatalytic preparation of 5-hydroxymethyl-2-furanic acid, but the reaction from HMF to HMFCA uses the organic solvent acetonitrile, which is not suitable for industrial production.

[0005] Chinese patent CN 116024239 A discloses the preparation of 5-hydroxymethyl-2-furanic acid using a biomass catalyst aldehyde dehydrogenase mutant. However, biomass catalysts are easily destroyed, limiting their application range, and are also difficult to recycle. Chinese patent CN112844487A discloses a lignin-supported porphyrin catalyst, which is complex to manufacture, time-consuming, and relatively expensive, making it unsuitable for industrial production.

[0006] Therefore, the present invention proposes a method for preparing 5-hydroxymethyl-2-furanic acid with reusable catalyst. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this invention is to provide a green, environmentally friendly and simple method for preparing 5-hydroxymethyl-2-furanic acid, especially in that the catalyst can be recycled multiple times.

[0008] The technical solution of the present invention is as follows:

[0009] A method for preparing 5-hydroxymethyl-2-furanic acid includes the following steps:

[0010] First, add the HMF solution and catalyst to a round-bottom flask, then add hydrogen peroxide dropwise, and stir under normal pressure to efficiently and selectively oxidize HMF to 5-hydroxymethyl-2-furanic acid.

[0011] Furthermore, the mass ratio of HMF to catalyst is 1:0.1-1; the molar ratio of HMF to hydrogen peroxide is 1:2-10; and the mass concentration of the HMF aqueous solution is 3%-12%.

[0012] Furthermore, the catalyst is a chitin-based AgO / AC catalyst, and its preparation process is as follows:

[0013] 1) Weigh out chitin and calcine it at high temperature in a N2 atmosphere. The material obtained after calcination is ready for use.

[0014] 2) Weigh out silver nitrate and add purified water, stir thoroughly to obtain a silver nitrate solution for later use;

[0015] 3) Add the material after calcination in step 1) to the silver nitrate solution prepared in step 2) and stir. After stirring evenly, add NaOH solution dropwise while stirring. After the addition is complete, introduce ozone to react. After the reaction is complete, the chitin-based AgO / AC catalyst can be obtained.

[0016] Further, in step 1), an appropriate amount of chitin is weighed and calcined at 500-800℃ for 3-6 hours in a N2 atmosphere.

[0017] Furthermore, in step 2), the molar ratio of silver nitrate to purified water is 1:13-20.

[0018] Furthermore, the specific process of step 3) is as follows:

[0019] The calcined chitin was added to a silver nitrate solution and stirred for 30 minutes. Then, 20% sodium hydroxide was added dropwise while stirring. After the addition was complete, stirring was continued for another 30 minutes. Ozone was then continuously introduced for 1 hour to carry out the reaction. After the reaction was completed, a chitin-based AgO / AC catalyst was obtained.

[0020] Furthermore, in step 3), the molar ratio of silver nitrate to sodium hydroxide is 1:1-1.5.

[0021] Further, the HMF solution and catalyst are added to a round-bottom flask, and hydrogen peroxide is added dropwise using a flow meter or peristaltic pump. The reaction is carried out under atmospheric pressure and stirring, with the reaction temperature controlled at 10-30℃ and the reaction time at 10-80 minutes.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1) In this invention, HMF solution and catalyst are added to a round-bottom flask, and then hydrogen peroxide is added dropwise. Under atmospheric pressure and stirring, HMF is efficiently and selectively oxidized to 5-hydroxymethyl-2-furanic acid, and the yield of 5-hydroxymethyl-2-furanic acid is 94.30%.

[0024] 2) Compared with traditional catalysts, the chitin-based AgO / AC catalyst prepared by ozone reduction in this invention can be recycled multiple times. The raw material for preparing the catalyst is chitin, which is a biomass raw material of shrimp and crab shells. It is environmentally friendly and has low production cost.

[0025] 3) The oxidant used in this invention is hydrogen peroxide, which is green, environmentally friendly, and conducive to environmental protection;

[0026] 4) The entire reaction operation of this invention is simple and conducive to large-scale industrial production. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited to the scope described.

[0028] Example 1 Preparation of catalyst

[0029] 1) Weigh 10g of chitin and calcine it in N2 at 600℃ for 4 hours;

[0030] 2) Weigh 3.4g of silver nitrate and add purified water to a final volume of 50g, then stir thoroughly until well combined;

[0031] 3) Add the calcined chitin to the silver nitrate solution and stir for 30 minutes. While stirring, add 4g of sodium hydroxide with a mass concentration of 20% dropwise. After the addition is complete, continue stirring for 30 minutes. Continue stirring while passing ozone through for 1 hour to obtain the chitin-based AgO / AC catalyst.

[0032] Example 2 Preparation of 5-hydroxymethyl-2-furanic acid

[0033] Weigh 2g of HMF, 10g of water, and 4.64g of 30% hydrogen peroxide into a round-bottom flask. After stirring evenly, add 1.0g of the catalyst chitin-based AgO / AC prepared in Example 1. Set the stirrer speed to 200 rpm and control the water bath temperature to 10℃. React for 10 min, 15 min, 20 min, 25 min, and 30 min. Take an appropriate amount of sample for liquid chromatography analysis to obtain the yield of 5-hydroxymethyl-2-furanoic acid.

[0034] Example 3-11 Preparation of 5-hydroxymethyl-2-furanic acid

[0035] Examples 3-11 modify the reaction temperature, catalyst dosage, hydrogen peroxide dosage, and other steps are the same as those in Example 2.

[0036] The reaction results of Examples 2-11 are shown in Table 1 below:

[0037] Table 1 shows the yields of 5-hydroxymethyl-2-furanic acid prepared in Examples 2-11.

[0038]

[0039] As shown in Table 1, the results of Examples 2-6 indicate that the higher the reaction temperature, the faster the reaction rate, and the higher the yield of HMFCA when the reaction time is controlled at 20-25 min.

[0040] The results from Examples 4, 7 and 8 show that the more catalyst there is, the faster the reaction is, and the reaction rate does not change much when the catalyst reaches a certain value.

[0041] The results from Examples 4, 9, 10 and 11 show that the more hydrogen peroxide used, the faster the reaction rate, and the reaction rate does not change much when the amount of hydrogen peroxide reaches a certain value.

[0042] The results from Examples 2-10 indicate that the decrease in HMFCA yield due to excessive reaction time may be due to over-oxidation and the generation of byproducts.

[0043] Examples 12-16 Catalyst Reuse

[0044] After the previous reaction was completed, the catalyst was filtered, washed, dried and reused. The catalyst used was chitosan-based AgO / AC. Other steps were the same as in Example 2, and other reaction conditions remained unchanged. The reaction results are shown in Table 2 below.

[0045] Table 2 shows the reaction results after multiple applications of the catalyst.

[0046]

[0047] As shown in Table 2, the results of Examples 4 and 12-16 indicate that repeated use of the catalyst has little impact on the yield of HMFCA, meaning that the catalyst prepared in this invention can be reused multiple times.

Claims

1. A method for preparing 5-hydroxymethyl-2-furanic acid, characterized in that... Includes the following steps: First, add the HMF solution and catalyst to a round-bottom flask, then add hydrogen peroxide dropwise, and stir under normal pressure to efficiently and selectively oxidize HMF to 5-hydroxymethyl-2-furanic acid; The mass ratio of HMF to catalyst is 1:0.1-1; the molar ratio of HMF to hydrogen peroxide is 1:2-10; and the mass concentration of the HMF aqueous solution is 3%-12%. Add HMF solution and catalyst to a round-bottom flask, then add hydrogen peroxide dropwise using a flow meter or peristaltic pump. Under normal pressure and stirring, control the reaction temperature at 10-30℃ and the reaction time at 10-80 minutes. The catalyst is a chitin-based AgO / AC catalyst, and its preparation process is as follows: 1) Weigh out chitin and calcine it at high temperature in a N2 atmosphere. The material obtained after calcination is ready for use. 2) Weigh out silver nitrate and add purified water, stir thoroughly to obtain a silver nitrate solution for later use; 3) Add the material after calcination in step 1) to the silver nitrate solution prepared in step 2) and stir. After stirring evenly, add NaOH solution dropwise while stirring. After the addition is complete, introduce ozone to react. After the reaction is complete, the chitin-based AgO / AC catalyst can be obtained.

2. The method for preparing 5-hydroxymethyl-2-furanic acid according to claim 1, characterized in that... In step 1), weigh an appropriate amount of chitin and calcine it at 500-800℃ for 3-6 hours in a N2 atmosphere.

3. The method for preparing 5-hydroxymethyl-2-furanic acid according to claim 1, characterized in that... In step 2), the molar ratio of silver nitrate to purified water is 1:13-20.

4. The method for preparing 5-hydroxymethyl-2-furanic acid according to claim 1, characterized in that... The specific process of step 3) is as follows: The calcined chitin was added to a silver nitrate solution and stirred for 30 minutes. Then, 20% sodium hydroxide was added dropwise while stirring. After the addition was complete, stirring was continued for another 30 minutes. Ozone was then continuously introduced for 1 hour to carry out the reaction. After the reaction was completed, a chitin-based AgO / AC catalyst was obtained.

5. The method for preparing 5-hydroxymethyl-2-furanic acid according to claim 4, characterized in that... In step 3), the molar ratio of silver nitrate to sodium hydroxide is 1:1-1.5.

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