A preparation method of bis-(5-hydroxymethylfurfuryl) ether

Abstract

The invention discloses a preparation method of bis-(5-hydroxymethylfurfuryl) ether, and the process steps are as follows: S1: adding solvent, bis-(5-formylfurfuryl) ether and non-precious metal catalyst to an autoclave; S2: starting stirring and replacing with protective gas, and introducing a certain pressure of hydrogen into the autoclave; S3: controlling the temperature in the autoclave between 80°C and 160°C, stirring the reaction for 0.5-24 hours; S4: after the reaction is completed, cooling to 50-60°C, filtering while hot, collecting the filtrate, and concentrating the filtrate to three times the volume of the bis-(5-formylfurfuryl) ether feeding amount; S5: separating the solid and liquid phases, applying the filtrate, and transferring the obtained solid to an oven for drying to obtain the product. The raw materials used in the catalyst used in the present invention are all non-precious metals, which greatly reduces the catalyst manufacturing cost, improves the economic benefits of bis-(5-hydroxymethylfurfuryl) ether production, realizes efficient conversion of biomass resources, and provides practical support for the comprehensive utilization and industrialization of biomass resources.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing bis-(5-hydroxymethylfurfuryl) ether. Background Art

[0002] At present, bis-(5-hydroxymethylfurfuryl) ether is generally prepared by reduction of bis-(5-formylfurfuryl) ether. According to literature reports, in the presence of palladium-carbon catalyst, under a certain pressure of hydrogen, bis-(5-formylfurfuryl) ether can be reduced to bis-(5-hydroxymethylfurfuryl) ether. However, the production cost is very high due to the precious metal catalyst, especially the precious metal catalyst with a palladium content of up to 30%, so it is not an ideal industrial route. In addition, the use of palladium-carbon also has a certain flammability risk, which increases the safety cost.

[0003] In view of this, how to synthesize bis-(5-hydroxymethylfurfuryl) ether through a mild, efficient and low-cost method is an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for preparing bis-(5-hydroxymethylfurfuryl) ether, which adopts a non-precious metal catalyst hydrogenation process, thereby avoiding the problems of high production cost and high safety cost in traditional processes to a certain extent, and is more suitable for the industrial production of special and specialized chemicals.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A method for preparing bis-(5-hydroxymethylfurfuryl) ether comprises the following process steps: S1: adding a certain proportion of solvent, bis-(5-formylfurfuryl) ether and non-precious metal catalyst into a high-pressure reactor; S2: Start stirring and perform replacement treatment with protective gas several times, and introduce a certain pressure of hydrogen into the high-pressure reactor; S3: Control the temperature in the autoclave to be between 80-160°C, and stir the reaction for 0.5-24 hours; S4: After the reaction is completed, the temperature is lowered to 50-60°C, filtered while hot, the filtrate is collected, and the filtrate is concentrated to a volume three times the amount of bis-(5-formylfurfuryl) ether fed; S5: Separate the solid and liquid phases, apply the filtrate, and transfer the obtained solid to an oven for drying to obtain bis-(5-hydroxymethylfurfuryl) ether.

[0006] According to a further technical solution, the non-precious metal catalyst is one of Cu-Zn-Al, Cu / SiO2 or Raney copper.

[0007] In a further technical solution, the solvent is one of methanol, tetrahydrofuran or 2-methyltetrahydrofuran.

[0008] According to a further technical solution, the mass ratio of bis-(5-formylfurfuryl) ether and the solvent added in step S1 is 1:(3-10); the mass ratio of bis-(5-formylfurfuryl) ether and the non-precious metal catalyst added is 1:(0.01-0.5).

[0009] According to a further technical solution, nitrogen replacement is performed three times in step S2.

[0010] According to a further technical solution, the hydrogen introduced in step S2 is maintained at 0.5-5 MPa.

[0011] According to a further technical solution, in step S3, the temperature in the autoclave is controlled between 140° C. and 160° C., and the reaction is stirred for 0.5 to 6 hours.

[0012] According to a further technical solution, the oven drying temperature in step S5 is 40-60°C.

[0013] The present invention proposes that bis-(5-formylfurfuryl) ether, a solvent and a copper-containing catalyst are added to a high-pressure reactor, replaced with an inert gas, and heated to react under a hydrogen atmosphere. After the reaction is completed, bis-(5-hydroxymethylfurfuryl) ether is obtained. In this reaction, hydrogen is used as a reducing agent. Under the catalytic action of a non-precious metal copper-containing catalyst, hydrogen molecules (H2) are activated and decomposed into hydrogen anions or hydrogen cations and electrons. The activated hydrogen anions (H - ) is transferred to the carbon atom of the aldehyde group. The carbon atom carries a partial positive charge, and because the electronegativity of the oxygen atom is stronger, the carbon atom is more likely to accept electrons. The transfer of the hydrogen anion causes the aldehyde group to be reduced to the corresponding alcohol.

[0014] In summary, the present invention uses a copper-containing catalyst as a catalyst, uses hydrogen as a hydrogen donor for reduction, and efficiently catalyzes the selective hydrogenation of bis-(5-formylfurfuryl) ether to bis-(5-hydroxymethylfurfuryl) ether, and the product selectivity is high and stable; the raw materials used in the catalyst used in the present invention are all non-precious metals, which greatly reduces the catalyst manufacturing cost, improves the economic benefits of bis-(5-hydroxymethylfurfuryl) ether production, can achieve efficient conversion of biomass resources, and provide practical support for the comprehensive utilization and industrialization of biomass resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The H NMR spectrum of the product prepared by the present invention; Figure 2 It is the reaction formula of the product prepared by the present invention. DETAILED DESCRIPTION

[0016] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. Example 1

[0017] In a 2 L high-pressure reactor, 791.0 g of methanol, 100.0 g of bis-(5-formylfurfuryl) ether, and 5.0 g of catalyst Cu-Zn-Al were added, stirring was started, nitrogen was replaced three times, hydrogen was introduced to maintain the hydrogen pressure at 3.0 MPa, the temperature was raised to 140 °C and stirred for reaction for 6 h, the temperature was lowered to 60 °C, filtered while hot, the filtrate was collected, the filtrate was concentrated to about 300 mL, and the filter cake was transferred to an oven and dried at 45 °C for 12 h to obtain 93.2 g of off-white solid with a purity of 97.9%. Example 2

[0018] In a 2 L high-pressure reactor, add 890.0 g of tetrahydrofuran, 100.0 g of bis-(5-formylfurfuryl) ether, and 5.0 g of catalyst Cu-Zn-Al, start stirring, replace with nitrogen three times, introduce hydrogen to maintain the hydrogen pressure at 3.0 MPa, raise the temperature to 140°C and stir to react for 6 h, cool to 60°C, filter while hot, collect the filtrate, concentrate the filtrate to about 300 mL, filter, transfer the filter cake to an oven, and dry at 45°C for 12 h to obtain 91.2 g of off-white solid with a purity of 97.3%. Example 3

[0019] In a 2 L high-pressure reactor, 863.0 g of 2-methyltetrahydrofuran, 100.0 g of bis-(5-formylfurfuryl) ether, and 5.0 g of catalyst Cu-Zn-Al were added, stirring was started, nitrogen was replaced three times, hydrogen was introduced to maintain the hydrogen pressure at 3.0 MPa, the temperature was raised to 140°C and stirred for reaction for 6 h, the temperature was lowered to 60°C, filtered while hot, the filtrate was collected, the filtrate was concentrated to about 300 mL, and the filter cake was transferred to an oven and dried at 45°C for 12 h to obtain 91.2 g of off-white solid with a purity of 97.5%. Example 4

[0020] In a 2 L high-pressure reactor, add 890.0 g of tetrahydrofuran, 100.0 g of bis-(5-formylfurfuryl) ether, and 5.0 g of catalyst Cu / SiO2, start stirring, replace with nitrogen three times, introduce hydrogen to maintain the hydrogen pressure at 3.0 MPa, raise the temperature to 140°C, stir and react for 6 h, cool to 60°C, filter while hot, collect the filtrate, concentrate the filtrate to about 300 mL, filter, transfer the filter cake to an oven, and dry at 45°C for 12 h to obtain 92.2 g of off-white solid with a purity of 97.1%. Example 5

[0021] In a 2 L high-pressure reactor, add 890.0 g of tetrahydrofuran, 100.0 g of bis-(5-formylfurfuryl) ether, and 5.0 g of catalyst Raney copper, start stirring, replace with nitrogen three times, introduce hydrogen to maintain the hydrogen pressure at 3.0 MPa, raise the temperature to 140°C, stir and react for 6 h, cool to 60°C, filter while hot, collect the filtrate, concentrate the filtrate to about 300 mL, filter, transfer the filter cake to an oven, and dry at 45°C for 12 h to obtain 86.2 g of off-white solid with a purity of 96.1%.

[0022] Figure 1 The H NMR spectrum of the product prepared by the present invention; Figure 1 This indicates that the chemical shift of the product is consistent with that of the target product; the relevant reaction equation is as follows Figure 2 shown.

[0023] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing bis-(5-hydroxymethylfurfuryl) ether, characterized in that: The process steps include: S1: adding a certain proportion of solvent, bis-(5-formylfurfuryl) ether and non-precious metal catalyst into a high-pressure reactor; S2: Start stirring and perform replacement treatment with protective gas several times, and introduce a certain pressure of hydrogen into the high-pressure reactor; S3: Control the temperature in the autoclave to be between 80-160°C, and stir the reaction for 0.5-24 hours; S4: After the reaction is completed, the temperature is lowered to 50-60°C, filtered while hot, the filtrate is collected, and the filtrate is concentrated to a volume three times the amount of bis-(5-formylfurfuryl) ether fed; S5: Separate the solid and liquid phases, apply the filtrate, and transfer the obtained solid to an oven for drying to obtain bis-(5-hydroxymethylfurfuryl) ether.

2. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: The non-precious metal catalyst is one of Cu-Zn-Al, Cu / SiO2 or Raney copper.

3. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: The solvent is one of methanol, tetrahydrofuran or 2-methyltetrahydrofuran.

4. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: The mass ratio of bis-(5-formylfurfuryl) ether and the solvent added in step S1 is 1:(3-10); the mass ratio of bis-(5-formylfurfuryl) ether and the non-precious metal catalyst added is 1:(0.01-0.5).

5. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: In step S2, nitrogen replacement is performed three times.

6. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: In step S2, the hydrogen gas is introduced and maintained at 0.5-5 MPa.

7. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: In step S3, the temperature in the autoclave is controlled between 140-160° C., and the reaction is stirred for 0.5-6 hours.

8. The method for preparing bis-(5-hydroxymethylfurfuryl) ether according to claim 1, characterized in that: The oven drying temperature in step S5 is 40-60°C.

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