A preparation method of 2,5-furandicarboxaldehyde

Abstract

The invention discloses a kind of preparation method of 2,5-furandicarboxaldehyde, including:S1, dichloromethane is added in reactor, stirring is opened, by 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine, potassium bicarbonate are added in reactor in sequence, and reaction system is formed;S2, reaction system temperature is at 20 ℃ 30 ℃, sodium hypochlorite is added dropwise;S3, dropwise addition is completed, control reaction system temperature at 20 ℃ 20 ℃, stirring reaction 0.5 24 hours;S4, reaction is completed, liquid separation is left to stand, organic phase is collected;S5, organic phase is concentrated under reduced pressure in kettle, adds water, suction filtration, filter cake is dried and obtains 2,5-furandicarboxaldehyde. The present invention optimizes treatment process, can realize kilogram level to ton level amplification production, to solve the problem that existing market 2,5-furandicarboxaldehyde production cost is high, treatment process is complicated.

Description

Technical Field

[0001] The present invention relates to the field of biomass resource utilization, and in particular to a method for preparing 2,5-furandicarboxaldehyde. Background Art

[0002] Currently, 2,5-furandicarboxaldehyde is typically produced by the oxidation of 5-hydroxymethylfurfural. According to literature, this is achieved by catalytic oxidation of 5-hydroxymethylfurfural under equivalent alkaline conditions. However, the use of large amounts of alkali is not only costly, but also difficult to treat, prone to equipment damage, and requires complex post-processing, making it unsuitable for industrial production.

[0003] Chinese patent application publication number CN106008416A discloses a method for preparing 2,5-furandicarboxaldehyde, comprising: using 5-hydroxymethylfurfural as a raw material and Cu(NO3)2·3H2O as an oxidant to produce 2,5-furandicarboxaldehyde in a water-acetonitrile / non-polar solvent two-phase reaction system. However, in this technical solution, 5-hydroxymethylfurfural and Cu(NO3)2·3H2O are stirred evenly in a mixed solution of acetonitrile and water, and then toluene is added. The reaction is carried out at a temperature of 120°C and a stirring speed of 1200 rpm for 1 hour. After the reaction is completed, the phases are separated, and the non-polar solvent phase is concentrated under reduced pressure to obtain crude 2,5-furandicarboxaldehyde. 2,5-furandicarboxaldehyde is then recrystallized from dichloromethane. This reaction process has a high temperature, high industrial energy consumption, and also affects safety to a certain extent. Therefore, it is not an ideal choice for industrial scale-up production.

[0004] In view of this, in view of the above shortcomings of the existing technology, how to realize the industrialized production of 2,5-furandicarboxaldehyde is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of 2,5-furandicarboxaldehyde, which optimizes the treatment process and can achieve scale-up production from kilograms to tons, so as to solve the problems of high production cost and complex treatment process of 2,5-furandicarboxaldehyde in the existing market.

[0006] In order to solve the above problems, the present invention provides a method for preparing 2,5-furandicarboxaldehyde, comprising the following steps:

[0007] S1. Add dichloromethane to the reactor, start stirring, and add 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine, and potassium bicarbonate to the reactor in sequence to form a reaction system;

[0008] S2, the reaction system temperature is -20 ℃ -30 ℃, sodium hypochlorite is added dropwise;

[0009] S3, after the addition is complete, the reaction system temperature is controlled at 20°C-20°C, and the reaction is stirred for 0.5-24 hours;

[0010] S4, after the reaction is completed, the liquid is allowed to stand and separate, and the organic phase is collected;

[0011] S5. The organic phase is concentrated under reduced pressure in a kettle, water is added, and the mixture is filtered. The filter cake is dried to obtain 2,5-furandicarboxaldehyde.

[0012] In step S1, the ratio of 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine, and potassium bicarbonate is 30-70:0.3-1:0.4-4. The present invention uses 0.01-0.1 equivalents of potassium bicarbonate as a reaction scheme, which simplifies the post-reaction processing steps, greatly reduces material costs, and simplifies post-processing operations. A further preferred ratio is 50.0:0.62:0.397-3.97, and a most preferred ratio is 50.0:0.62:1.985. At this ratio, the yield of 2,5-furandicarboxaldehyde is the highest.

[0013] In step S2, the temperature of the reaction system is between -5°C and 10°C, and sodium hypochlorite is added dropwise.

[0014] In step S3, the temperature of the reaction system is controlled at -5°C to 15°C, and the reaction is stirred for 0.5-3 hours.

[0015] In step S4, the liquid is allowed to stand and separated, and the organic phase is collected, which specifically includes:

[0016] After standing and separating, the lower layer is the organic phase. The upper aqueous phase is discharged and the organic phase is transferred to a reactor. The aqueous phase is extracted with dichloromethane 1-3 times and the organic phases are combined.

[0017] In step S5, the drying temperature is 40°C to 50°C.

[0018] Most preferably, the method for preparing 2,5-furandicarboxaldehyde comprises the following steps:

[0019] S1. Add dichloromethane to the reaction vessel, start stirring, and add 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine, and potassium bicarbonate to the vessel in sequence;

[0020] S2. Control the temperature between -20°C and 30°C and slowly add sodium hypochlorite;

[0021] S3, after the addition is complete, the reaction system temperature is controlled between 20°C and 20°C, and the reaction is stirred for 0-24 hours;

[0022] S4, after the reaction is completed, the liquid is allowed to stand and separated, the lower organic phase is collected, the upper aqueous phase is released, the organic phase is transferred to a reactor, and the aqueous phase is extracted with dichloromethane 1-3 times;

[0023] S5, combine the organic phase, concentrate the organic phase in the kettle under reduced pressure to 3-5V, add water 5V

[0024] S6. Filter by suction and transfer the filter cake to an oven at 45°C for drying.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The invention adopts 5-hydroxymethylfurfural as a raw material and oxidizes it by potassium bicarbonate and sodium hypochlorite. The reaction is mild, by-products are few, the operation is simple, the reaction is mild, and the safety is high. The method is suitable for large-scale chemical production.

[0027] The whole process of the present invention requires short reaction time, has high efficiency, mild reaction, low cost, simple operation, and is suitable for large-scale industrial production.

[0028] The preparation method of the present invention has the advantages of high production efficiency, high yield, low cost, convenient operation, etc., simple production and purification, and is of great significance to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The following is a reaction scheme for synthesizing the compounds of the present invention;

[0030] Figure 2 Mass spectrum of 2,5-furandicarboxaldehyde prepared in Example 1.

[0031] Figure 3 This is the chromatogram of 2,5-furandicarboxaldehyde prepared in Example 1.

[0032] Figure 4 This is the hydrogen spectrum of furan dicarboxaldehyde prepared in Example 1. DETAILED DESCRIPTION

[0033] Example 1

[0034] In a 1L reactor, stirring was started, 265.0 g of dichloromethane was added, 50.0 g of 5-hydroxymethylfurfural was added, 0.62 g of 2,2,6,6-tetramethylpiperazine was added, 0.397 g of potassium bicarbonate was added, 66.3 g of dichloromethane was added to rinse the reactor wall, the reaction system temperature was controlled at -5 to 5 ° C, and an aqueous sodium hypochlorite solution was slowly added dropwise. After the dropwise addition, the mixture was kept at 5 ± 10 ° C and stirred for 1 h. The raw material was detected to be ≤0.5% by the central control. The reaction was allowed to stand for 10 min, and the lower organic phase was collected. The aqueous phase was washed three times with 325.0 g of dichloromethane, the organic phases were combined, and the organic phase was concentrated under reduced pressure to about 150.0 g. 250.0 g of water was added to the organic phase, filtered, and the filter cake was transferred to an oven and dried at 45 ° C to obtain a white product with a purity of 99.4% and a yield of 81.3%.

[0035] The reaction scheme for synthesizing the compounds of the present invention is as follows: Figure 1 shown.

[0036] like Figure 2 As shown, the mass spectrum ([M+1]=125) of 2,5-furandicarboxaldehyde prepared in Example 1 shows that the relative molecular weight is consistent with that of the target product.

[0037] like Figure 3 As shown in FIG. 1 , the chromatogram of 2,5-furandicarboxaldehyde prepared in Example 1 shows that the purity of 2,5-furandicarboxaldehyde is 99.4%.

[0038] like Figure 4 As shown, the hydrogen spectrum of furan dicarboxaldehyde prepared in Example 1 shows that the chemical shift is consistent with that of the target product.

[0039] Example 2

[0040] In a 1L reactor, stirring was started, 265.0 g of dichloromethane was added, 50.0 g of 5-hydroxymethylfurfural was added, 0.62 g of 2,2,6,6-tetramethylpiperazine was added, 1.985 g of potassium bicarbonate was added, 66.3 g of dichloromethane was added to rinse the reactor wall, the reaction system temperature was controlled at -5 to 5 ° C, and an aqueous sodium hypochlorite solution was slowly added dropwise. After the dropwise addition, the mixture was kept at 5 ± 10 ° C and stirred for 1 h. The raw material was detected to be ≤0.5% by the central control. The reaction was allowed to stand for 10 min, and the lower organic phase was collected. The aqueous phase was washed three times with 325.0 g of dichloromethane, the organic phases were combined, and the organic phase was concentrated under reduced pressure to about 150.0 g. 250.0 g of water was added to the organic phase, filtered, and the filter cake was transferred to an oven and dried at 45 ° C to obtain an off-white product with a purity of 99.1% and a yield of 85.7%.

[0041] Example 3

[0042] In a 1L reactor, stirring was started, 265.0 g of dichloromethane was added, 50.0 g of 5-hydroxymethylfurfural was added, 0.62 g of 2,2,6,6-tetramethylpiperazine was added, 3.97 g of potassium bicarbonate was added, 66.3 g of dichloromethane was added to rinse the reactor wall, the reaction system temperature was controlled at -5 to 5 ° C, and an aqueous sodium hypochlorite solution was slowly added dropwise. After the dropwise addition, the mixture was kept at 5±10 ° C and stirred for 1 h. The raw material was detected to be ≤0.5% by the central control. The reaction was allowed to stand for 10 min, and the lower organic phase was collected. The aqueous phase was washed three times with 325.0 g of dichloromethane, the organic phases were combined, and the organic phase was concentrated under reduced pressure to about 150.0 g. 250.0 g of water was added to the organic phase, filtered, and the filter cake was transferred to an oven and dried at 45 ° C to obtain a white product with a purity of 99.3% and a yield of 83.1%.

Claims

1. A method for preparing 2,5-furandicarbaldehyde, characterized in that: The steps include: S1. Add dichloromethane to the reactor, start stirring, and add 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine, and potassium bicarbonate to the reactor in sequence to form a reaction system; The ratio of 5-hydroxymethylfurfural, 2,2,6,6-tetramethylpiperazine and potassium bicarbonate is 30-70:0.3-1:0.4-4; S2, the reaction system temperature is -20 ℃ -30 ℃, sodium hypochlorite is added dropwise; S3, after the addition is complete, the reaction system temperature is controlled at -5°C to 15°C, and the reaction is stirred for 0.5-24 hours; S4, after the reaction is completed, the liquid is allowed to stand and separate, and the organic phase is collected; S5. The organic phase is concentrated under reduced pressure in an autoclave, water is added, and the product is filtered. The filter cake is dried to obtain 2,5-furandicarboxaldehyde.

2. The preparation method of 2,5-furandicarbaldehyde according to claim 1, wherein In step S2, the temperature of the reaction system is between -5°C and 10°C, and sodium hypochlorite is added dropwise.

3. The preparation method of 2,5-furandicarbaldehyde according to claim 1, characterized in that In step S3, the reaction is stirred for 0.5-3 hours.

4. The preparation method of 2,5-furandicarbaldehyde according to claim 1, wherein In step S4, the liquid is allowed to stand and separated, and the organic phase is collected, which specifically includes: After standing and separating, the lower layer is the organic phase. The upper aqueous phase is discharged and the organic phase is transferred to a reactor. The aqueous phase is extracted with dichloromethane 1-3 times and the organic phases are combined.

5. The preparation method of 2,5-furandicarbaldehyde according to claim 1, wherein In step S5, the drying temperature is 40°C to 50°C.

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