Method for preparing 5-hydroxyfurfural by catalyzing biomass based on tetramethylpropanediamine acidic ionic liquid

Abstract

The invention discloses a method for preparing 5-hydroxyfurfural by catalyzing biomass based on tetramethylpropanediamine acidic ionic liquid, which comprises the following steps: mixing biomass, tetramethylpropanediamine acidic ionic liquid, a saturated sodium chloride solution and a solvent, and carrying out high-temperature reaction to obtain the 5-hydroxyfurfural, the structural general formula of the tetramethylpropanediamine acidic ionic liquid is as shown in the following formula (I), according to the preparation method disclosed by the invention, on one hand, biomass and other wastes or low-added-value substances are directly subjected to one-step catalytic hydrolysis to prepare high-added-value substances, on the other hand, the catalytic activity of the catalyst is high, the highest product yield can reach about 61%, and the catalyst can be repeatedly used; the invention also overcomes the problems of equipment corrosion, waste acid pollution and the like caused by using inorganic acid as a catalyst. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and in particular to a method for preparing 5-hydroxyfurfural from biomass based on the catalysis of tetramethylpropylenediamine acidic ionic liquid. Background Art

[0002] The molecular structure of 5-hydroxymethylfurfural is composed of a furan ring, a hydroxymethyl group and an aldehyde group. It is easily oxidized and hydrolyzed. 5-hydroxymethylfurfural is an important chemical intermediate. Its direct utilization itself is relatively small, but its derivatives are widely used. For example, 5-hydroxymethylfurfural functionalized plastic materials have the advantage of being biodegradable, which has an important impact on the development of a green and low-carbon economy.

[0003] 5-Hydroxyfurfural is primarily produced by the hydrolysis of carbohydrates containing hexose structural units. Currently, the commonly used solvent systems for the preparation of 5-HMF include single-phase systems, biphasic systems, and ionic liquid systems. Early research focused on using inorganic acids as catalysts in water. However, the catalytic effect is generally poor in reaction systems using water as the sole solvent. Furthermore, the use of inorganic acids as catalysts presents problems such as high corrosion to equipment, the inability to recycle the catalyst, and the generation of large amounts of waste liquid and waste residue. Due to the propensity for side reactions in single-phase solvent systems for 5-HMF, the yield is very low, and 5-HMF is difficult to separate and purify in single-phase solvents. To overcome the shortcomings of single-phase solvent systems, biphasic solvent systems have attracted widespread attention from researchers. Biphasic systems, due to their adjustability, separability, recyclability, and reusability, offer new insights into the development of efficient and safe processes for the production of 5-HMF. The biphasic solvent system for preparing 5-HMF consists of a reaction phase (an aqueous solution or a water-organic solvent mixture) and an extraction phase (an organic phase). After 5-HMF is generated in the reaction phase, it is immediately transferred to the aqueous phase. Therefore, the concentration of 5-HMF in the reaction phase remains low, avoiding side reactions and increasing the yield of 5-HMF. Ionic liquids are liquid at room temperature, have virtually no vapor pressure, are nonvolatile, maintain stable chemical properties over a wide temperature range, and have excellent solubility for glucose.

[0004] Currently, the production of 5-HMF by catalyzing the hydrolysis of biomass using a single ionic liquid as a solvent requires a large amount of ionic liquid, resulting in high costs and hindering industrial production applications. Furthermore, the yield of 5-HMF by catalyzing biomass to 5-HMF using ionic liquids as catalysts is low, less than 60%, and the production of byproducts is high (Fuel 268(2020)117136). However, very few relevant research reports have been published.

[0005] Therefore, there is still much room for improvement in the yield of 5-hydroxymethylfurfural prepared by biomass hydrolysis using ionic liquids as catalysts. Summary of the Invention

[0006] In response to the above-mentioned problems existing in the prior art, the present invention discloses a method for preparing 5-hydroxyfurfural. Using tetramethylpropylenediamine-based acidic ionic liquid as a catalyst, on the one hand, waste such as biomass or low-value-added materials are directly catalytically hydrolyzed in one step to produce 5-hydroxymethylfurfural, a platform compound that can be used in fine chemical production, thereby turning waste into treasure and promoting sustainable development and environmental protection. On the other hand, the catalyst has high catalytic activity, can effectively increase the reaction rate and improve the product yield, up to about 61%, and can be reused. The present invention also overcomes the problems of equipment corrosion and waste acid pollution caused by using inorganic acids as catalysts.

[0007] The specific technical solutions are as follows:

[0008] A method for preparing 5-hydroxyfurfural from biomass based on the catalysis of tetramethylpropanediamine acidic ionic liquid:

[0009] Biomass, tetramethylpropylenediamine acidic ionic liquid, saturated sodium chloride solution and solvent are mixed and reacted at high temperature to prepare 5-hydroxyfurfural;

[0010] The general structural formula of the tetramethylpropylenediamine acidic ionic liquid is shown in the following formula (I):

[0011]

[0012] Where R - Selected from F - 、Cl - Br - , I - 、HSO4 - 、H2PO4 - CF3SO3 - 、CH3SO3 - 、FeCl4 - 、AlCl4 - 、HSiO3 - 、H2PW 12 O 40 - 、 One or more of .

[0013] Preferred:

[0014] The biomass is selected from glucose and / or starch;

[0015] Further preferably, the biomass is selected from glucose.

[0016] Preferred:

[0017] The mass ratio of biomass to tetramethylpropylenediamine-based acidic ionic liquid is 1:(0.1-5.0);

[0018] More preferably, the mass ratio of biomass to tetramethylpropylenediamine-based acidic ionic liquid is 1:(1.5-2.5).

[0019] Preferred:

[0020] The mass volume ratio of biomass to saturated sodium chloride solution is 100: (0.25-1.0) mg / mL;

[0021] Further preferably, the mass volume ratio of biomass to saturated sodium chloride solution is 100:

[0022] (0.5~0.75)mg / mL; more preferably (100:0.5)mg / mL.

[0023] Preferred:

[0024] The solvent is selected from one or more of r-valerolactone, tetrahydrofuran, methyltetrahydrofuran, acetone, and ethylene glycol dimethyl ether;

[0025] More preferably, the solvent is selected from one or more of r-valerolactone, methyltetrahydrofuran, and acetone; more preferably r-valerolactone.

[0026] Preferred:

[0027] The mass volume ratio of biomass to solvent is 100:(1-10) mg / mL;

[0028] More preferably, the mass volume ratio of biomass to solvent is 100:(3-6) mg / mL; more preferably (100:4) mg / mL.

[0029] Preferred:

[0030] The temperature of the high temperature reaction is not higher than 200°C and the time is 1 to 5 hours;

[0031] More preferably, the temperature of the high temperature reaction is 140 to 180° C.; more preferably, 150 to 170° C., and the time is 1 to 4 hours.

[0032] In this method, the preparation method of the tetramethylpropylenediamine acidic ionic liquid is:

[0033] The intermediate, the Bronsted acid compound and water are mixed and reacted at 50-100° C. to obtain a tetramethylpropylenediamine-based acidic ionic liquid;

[0034] The structural formula of the intermediate is as follows:

[0035]

[0036] The Bronsted acid compound is selected from HF, HCl, HI, H2SO4, H3PO4, CF3SO3H, CH3SO3H, FeCl3, AlCl3, H2SiO3, H3PW 12 O 40 、 One or more of .

[0037] Preferred:

[0038] The mass ratio of the intermediate, the Bronsted acid compound and water is 1:(0.1-5):(0.1-10).

[0039] Further preferred:

[0040] The intermediate is prepared by the following method: reacting N,N,N′,N′-tetramethyl-1,3-propanediamine in 1,2-dichloroethane, adding 1,3-propane sultone to a flask, heating to 58° C., reacting for 2 hours, and then cooling to room temperature. The white solid product in the reaction solution is filtered out, washed once with petroleum ether and diethyl ether respectively, and then dried to obtain a white solid intermediate.

[0041] The specific reaction equation is shown below:

[0042]

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The tetramethylpropylenediamine-based acidic ionic liquid synthesized by the present invention contains tetramethylpropylenediamine and sulfonic acid units as cations, and halide ions (such as fluorine, chlorine, bromine, iodine), hydrogen sulfate, benzenesulfonate, methanesulfonate, etc. as anions to form an ionic liquid containing cations and anions;

[0045] The present invention uses tetramethylpropylenediamine acidic ionic liquid as a catalyst and biomass as a raw material to directly catalyze and hydrolyze 5-hydroxyfurfural in a one-step process. The raw materials are simple and readily available, and the reaction is mild and controllable. The catalyst has high catalytic activity, can effectively increase the reaction rate and product yield, up to about 61%, and can be repeatedly used. The present invention also overcomes the problems of equipment corrosion and waste acid pollution caused by using inorganic acids as catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is the H NMR spectrum of the intermediate prepared in Example 1;

[0047] Figure 2 This is the C NMR spectrum of the intermediate prepared in Example 1;

[0048] Figure 3 This is a high-resolution mass spectrum of the intermediate prepared in Example 1;

[0049] Figure 4 This is the H NMR spectrum of the ionic liquid [TMPDAPS]Cl prepared in Example 1;

[0050] Figure 5 This is the C NMR spectrum of the ionic liquid [TMPDAPS]Cl prepared in Example 1;

[0051] Figure 6 This is a high-resolution mass spectrum of the ionic liquid [TMPDAPS]Cl prepared in Example 1;

[0052] Figure 7 This is the infrared spectrum of the ionic liquid [TMPDAPS]Cl prepared in Example 1;

[0053] Figure 8 This is the H NMR spectrum of the ionic liquid [TMPDAPS]Br prepared in Example 32;

[0054] Figure 9 This is the C NMR spectrum of the ionic liquid [TMPDAPS]Br prepared in Example 32;

[0055] Figure 10 This is a high-resolution mass spectrum of the ionic liquid [TMPDAPS]Br prepared in Example 32;

[0056] Figure 11 This is the infrared spectrum of the ionic liquid [TMPDAPS]Br prepared in Example 32;

[0057] Figure 12 This is the H NMR spectrum of the ionic liquid [TMPDAPS]TsO prepared in Example 33;

[0058] Figure 13 This is the C NMR spectrum of the ionic liquid [TMPDAPS]TsO prepared in Example 33;

[0059] Figure 14 This is a high-resolution mass spectrum of the ionic liquid [TMPDAPS]TsO prepared in Example 33;

[0060] Figure 15 This is the infrared spectrum of the ionic liquid [TMPDAPS]TsO prepared in Example 33. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0062] In the description of the present invention, it should be noted that, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. Below, based on the overall structure of the present invention, its embodiments are described. Unless otherwise specified, the raw materials in the embodiments of the present invention are purchased through commercial channels.

[0063] Example 1

[0064] (1) Synthetic intermediates

[0065] N,N,N′,N′-tetramethyl-1,3-propanediamine (5.80 g, 44.5 mmol, 1.0 eq) and 60 mL of 1,2-dichloroethane were added to a 100 mL flask, and 1,3-propane sultone (10.88 g, 89.1 mmol, 2.0 eq) was added to the flask. The mixture was heated to 58°C and reacted for 2 hours, then cooled to room temperature. The white solid product in the reaction solution was filtered out, washed once with petroleum ether and diethyl ether, respectively, and then dried to obtain a white solid product, which was recorded as an intermediate (14.78 g, 89%).

[0066] The structural formula of the intermediate is:

[0067]

[0068] 1 H NMR(600MHz,D2O)δ3.62-3.55(m,4H,N-CH2-C-CH2-N),3.47(t,J=8.3Hz,4H,N-CH2-CC-SO3),3.20(s,12H,N-CH3) ,3.03(t,J=6.9Hz,4H,NCC-CH2-SO3),2.42-2.33(m,J=5.3Hz,2H,NC-CH2-CN),2.33-2.23(m,4H,NC-CH2-C-SO3). 13 C NMR(150MHz,D2O)δ62.62,59.90,50.80,46.97,18.10,16.44.HRMS(ESI,m / z)calcd for C 13 H 30 N2O6S2[(M+H] +375.15453,Found 375.1537.

[0069] The nuclear magnetic hydrogen spectrum of the intermediate prepared in this example is as follows Figure 1 As shown; the NMR carbon spectrum is as shown Figure 2 As shown in the high-resolution mass spectrum Figure 3 shown.

[0070] (2) Synthesis of ionic liquid [TMPDAPS]Cl

[0071] Hydrochloric acid (5.26 g, 37% mass fraction, 53.4 mmol) and intermediate 1 (9.98 g, 26.6 mmol) were added to a flask, and the reaction solution was stirred at 80°C for 3 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether, respectively, and dried at 120°C for 12 hours to obtain a light yellow solid [TMPDAPS]Cl with a mass of 10.87 g and a yield of 91.2%.

[0072] The structural formula of the ionic liquid [TMPDAPS]Cl is:

[0073]

[0074] 1 H NMR(600MHz,D2O)δ3.59-3.53(m,4H,N–CH2–C–CH2–N),3.45(t,J=8.3Hz,4H,N–CH2–C–C–SO3),3.18(s,12H,N–CH 3),3.01(t,J=7.0Hz,4H,N–C–C–CH2–SO3),2.39-2.33(m,2H,N–C–CH2–C–N),2.28-2.21(m,4H,N–C–CH2–C–SO3). 13 C NMR(150MHz,D2O)δ62.85,60.14,50.93,47.16,18.25,16.59.HRMS(ESI,m / z)calcd for:C 13 H 31 N2O6S2[(M-2HCl)+H] + :375.16235,Found:375.16347.FT-IR(KBr,cm -1 ):v 3443,3032,2960,2731,1638,1476,1195,1041,918.

[0075] The nuclear magnetic hydrogen spectrum of the ionic liquid prepared in this example is as follows Figure 4 As shown; the NMR carbon spectrum is as shown Figure 5 As shown in the high-resolution mass spectrum Figure 6 As shown, the infrared spectrum is as follows Figure 7 shown.

[0076] The reaction equation is as follows:

[0077]

[0078] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]Cl

[0079] Glucose (101.7 mg), ionic liquid [TMPDAPS]Cl (202 mg), 0.5 mL of saturated sodium chloride, and 4 mL of r-valerolactone were added to a pressure bottle and reacted at 160°C with rapid stirring for 2 hours. The pressure bottle was then cooled to room temperature and the reaction solution was centrifuged to remove solid impurities. 5-hydroxyfurfural (44.02 mg, 61.84% yield) was obtained. Since the reaction mixture only contained 5-hydroxyfurfural, ionic liquid [TMPDAPS]Cl, r-valerolactone, NaCl, and water, and since 5-hydroxyfurfural was readily soluble in ethyl acetate and the ionic liquid was readily soluble in water, 5-hydroxyfurfural was first isolated by extraction with ethyl acetate. The aqueous phase was then extracted with methyl isobutyl ketone, ethyl acetate, and n-butanol. After extraction, the aqueous phase was concentrated under vacuum to remove the organic solvent and water. The remaining solid was the ionic liquid [TMPDAPS]Cl.

[0080] Examples 2 to 8

[0081] The preparation process is basically the same as that in Example 1, except that the reaction time in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 1 below.

[0082] Table 1

[0083]

[0084]

[0085] Examples 9 to 12

[0086] The preparation process is basically the same as that of Example 5, except that the type of organic solvent used in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 2 below.

[0087] Table 2

[0088]

[0089] Examples 13 to 16

[0090] The preparation process is basically the same as that of Example 5, except that the amount of the organic solvent r-valerolactone used in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 3 below.

[0091] Table 3

[0092]

[0093] Examples 17 to 20

[0094] The preparation process is basically the same as that of Example 5, except that the reaction temperature used in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 4 below.

[0095] Table 4

[0096]

[0097]

[0098] Examples 21 to 23

[0099] The preparation process is basically the same as that of Example 1, except that the amount of saturated brine used in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 5 below.

[0100] Table 5

[0101]

[0102] Comparative Example 1

[0103] The preparation process is basically the same as that of Example 1, except that saturated brine is not added in step (3). The yields of 5-hydroxyfurfural prepared are listed in Table 5 above.

[0104] Examples 24 to 27

[0105] The preparation process is basically the same as that of Example 1, except that the glucose used in step (3) is replaced by other raw materials. The yields of 5-hydroxyfurfural prepared are listed in Table 6 below.

[0106] Table 6

[0107]

[0108] Examples 28 to 31

[0109] The preparation process is basically the same as that of Example 1, except that the mass of glucose used in step (3) is adjusted. The yields of 5-hydroxyfurfural prepared are listed in Table 7 below.

[0110] Table 7

[0111]

[0112] Example 32

[0113] (1) The synthesis of the intermediate is exactly the same as in Example 1.

[0114] (2) Synthesis of ionic liquid [TMPDAPS]Br

[0115] Hydrobromic acid (12.16 g, 40% by mass, 150.3 mmol) and the intermediate (28.14 g, 75.1 mmol) were added to a flask, and the reaction solution was stirred at 80°C for 5 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether, respectively, and then dried at 120°C for 12 hours to obtain a colloidal solid [TMPDAPS]Br with a mass of 37.00 g and a yield of 92%.

[0116] The structural formula of the ionic liquid [TMPDAPS]Br is:

[0117]

[0118] 1 H NMR(600MHz,D2O)δ3.60-3.55(m,4H,N–CH2–C–CH2–N),3.47(t,J=8.3Hz,4H,N–CH2–C–C–SO3),3.20(s,12H,N–CH 3),3.02(t,J=7.0Hz,4H,N–C–C–CH2–SO3),2.40-2.34(m,2H,N–C–CH2–C–N),2.29-2.23(m,4H,N–C–CH2–C–SO3). 13 C NMR(150MHz,D2O)δ62.87,60.18,50.94,50.88,47.18,18.23,16.66.MS(TOF,m / z)calcd for:C 13 H 31 N2O6S2[(M-2HBr)+H] + :375.162,Found:375.147.FT-IR(KBr,cm -1 ):v 3445,3025,2962,1635,1479,1202,1041,908. H NMR spectrum Figure 8 As shown; the NMR carbon spectrum is as shown Figure 9 As shown in the high-resolution mass spectrum Figure 10 As shown, the infrared spectrum is as follows Figure 11 shown.

[0119] The reaction equation is as follows:

[0120]

[0121] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]Br

[0122] Take glucose (100.9 mg) and ionic liquid [TMPDAPS]Br (243.7 mg), add 0.5 mL of saturated saline and 4 mL of tetrahydrofuran, and react with rapid stirring at 160 ° C for 3 hours. Then, cool the pressure bottle to room temperature, centrifuge the reaction solution to remove solid impurities, and measure 5-hydroxyfurfural (21.523 mg, 30.75%). The ionic liquid [TMPDAPS]Br can be recycled.

[0123] Example 33

[0124] (1) The synthesis of the intermediate is exactly the same as in Example 1.

[0125] (2) Synthesis of ionic liquid [TMPDAPS]TsO

[0126] p-Toluenesulfonic acid (2.22 g, 11.7 mmol), 0.5 g of water, and the intermediate (2.18 g, 5.8 mmol) were added to a flask. The reaction solution was stirred at 80°C for 4.5 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether, respectively, and dried at 90°C for 12 hours to obtain a white solid [TMPDAPS]TsO with a mass of 4.25 g and a yield of 96%.

[0127] The structural formula of the ionic liquid [TMPDAPS]TsO is:

[0128]

[0129] 1 H NMR(600MHz,D2O)δ7.63(d,J=8.3Hz,4H,(CH)2-C-SO3),7.31(d,J=7.9Hz,4H,Ts O,(CH)2-CC),3.50-3.45(m,4H,N–CH2–C–CH2–N),3.37(t,J=8.3Hz,4H,N-CH2–C –C–SO3),3.10(s,12H,N–CH3),2.93(t,J=7.0Hz,4H,N–C–C–CH2–SO3),2.33(s,6 H,CH3-C),2.31-2.24(m,2H,N–C–CH2–C–N),2.20-2.13(m,4H,N–C–CH2–C–SO3). 13C NMR(150MHz,D2O)δ142.45,139.58,129.47,125.34,62.74,60.06,50.76,47.06,20.48,20.46,18.15,16.48.HRMS(ESI,m / z):calcd for:C 13 H 31 N2O6S2[(M-2CH3C6H4SO3H)+H] + :375.16235,Found:375.16290.FT-IR(KBr,cm -1 ):v 3446,3032,2972,2230,1661,1601,1489,1205,1124,1042,916. H NMR spectrum Figure 12 As shown, the NMR carbon spectrum is as follows Figure 13 As shown in the high-resolution mass spectrum Figure 14 As shown, the infrared spectrum is as follows Figure 15 shown.

[0130] The reaction equation is as follows:

[0131]

[0132] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]TsO

[0133] Take glucose (100.8 mg) and ionic liquid [TMPDAPS]TsO (206 mg), add 0.5 mL of saturated saline and 3 mL of tetrahydrofuran, and react with rapid stirring at 160 ° C for 3 hours. After that, the pressure bottle is cooled to room temperature, and the reaction liquid is centrifuged to remove solid impurities. 5-hydroxyfurfural (22.89 mg, 32.70%) is measured. The ionic liquid [TMPDAPS]TsO can be recycled.

[0134] Example 34

[0135] (1) The synthesis of the intermediate is exactly the same as in Example 1.

[0136] (2) Synthesis of ionic liquid [TMPDAPS] CH3SO3

[0137] Methanesulfonic acid (1.18 g, 12.3 mmol), 0.5 g of water and the intermediate (2.30 g, 6.1 mmol) were added to a flask, and the reaction solution was reacted at 80°C for 3 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether respectively, and dried at 120°C for 12 hours to obtain a viscous liquid [TMPDAPS]CH3SO3 with a mass of 3.17 g and a yield of 91%.

[0138] The structural formula of the ionic liquid [TMPDAPS]CH3SO3 is:

[0139]

[0140] 1 H NMR(600MHz,D2O)δ3.51–3.47(m,4H),3.38(t,J=7.8Hz,4H),3.11(s,12H),2.9 3(t,J=7.0Hz,4H),2.74(d,J=2.2Hz,6H),2.31–2.27(m,2H),2.22–2.14(m,4H). 13 CNMR(150MHz,D2O)δ62.79,60.11,50.88,50.82,47.12,38.55,38.47,18.19,16.52.

[0141] The reaction equation is as follows:

[0142]

[0143] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]CH3SO3

[0144] Take glucose (107 mg) and ionic liquid [TMPDAPS]CH3SO3 (207.7 mg), add 0.5 mL of saturated saline and 3 mL of tetrahydrofuran, and react with rapid stirring at 160°C for 3 hours. Then, cool the pressure bottle to room temperature, centrifuge the reaction solution to remove solid impurities, and measure 5-hydroxyfurfural (31.504 mg, 47.02%). The ionic liquid [TMPDAPS]CH3SO3 can be recycled.

[0145] Example 35

[0146] (1) The synthesis of the intermediate is exactly the same as in Example 1.

[0147] (2) Synthesis of ionic liquid [TMPDAPS]HSO4

[0148] Concentrated sulfuric acid (1.31 g, 13.4 mmol) and 1.0 g of water were added to the intermediate (2.50 g, 6.7 mmol), and the reaction solution was reacted at 80°C for 2.5 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether respectively, and dried at 120°C for 12 hours to obtain a viscous liquid [TMPDAPS]HSO4 with a mass of 3.45 g and a yield of 90%.

[0149] The structural formula of the ionic liquid [TMPDAPS]HSO4 is:

[0150]

[0151] 1 H NMR (600MHz, D2O) δ3.58–3.50(m,4H),3.42(t,J=8.2Hz,4H),3.15(s,12H),2.98(t,J=7.0Hz,4H),2.36–2.28(m,2H),2.25–2.19(m,4H). 13 C NMR (150MHz, D2O) δ62.77, 60.08, 50.85, 47.09, 18.18, 16.52.

[0152] The reaction equation is as follows:

[0153]

[0154] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]HSO4

[0155] Take glucose (108.7 mg) and ionic liquid [TMPDAPS]HSO4 (228.8 mg), add 0.5 mL of saturated saline and 3 mL of tetrahydrofuran, and react with rapid stirring at 160°C for 2 hours. Then, cool the pressure bottle to room temperature, centrifuge the reaction solution to remove solid impurities, and measure 5-hydroxyfurfural (20.04 mg, 28.63%). The ionic liquid [TMPDAPS]HSO4 can be recycled.

[0156] Example 36

[0157] (1) The synthesis of the intermediate is exactly the same as in Example 1.

[0158] (2) Synthesis of ionic liquid [TMPDAPS]1,5-NS

[0159] 1,5-Naphthalenedisulfonic acid (3.08 g, 1.1 mmol), 1.0 g of water and the intermediate (2.00 g, 5.3 mmol) were added to a flask, and the reaction solution was stirred at 80°C for 5 hours. The reaction solution was then concentrated in vacuo, washed three times with toluene and ether, respectively, and dried at 100°C for 12 hours to obtain a white solid [TMPDAPS]1,5-NS with a mass of 4.80 g and a yield of 94%.

[0160] The structural formula of ionic liquid [TMPDAPS]1,5-NS is:

[0161]

[0162] 1H NMR(600MHz,D2O)δ8.80(d,J=8.6Hz,4H),8.17(d,J=7.3Hz,4H),7.70(t,J=7.6Hz,4H),3.42–3.38(m, 4H), 3.26 (t, J=8.3Hz, 4H), 3.01 (s, 12H), 2.89 (t, J=7.0Hz, 4H), 2.24–2.15 (m, 2H), 2.13–2.06 (m, 4H). 13 CNMR(150MHz,D2O)δ138.98,129.35,129.33,128.92,126.57,126.28,126.25,62.64,59.95,50.70,50.62,47.00,18.07,16.37.

[0163] The reaction equation is as follows:

[0164]

[0165] (3) Preparation of 5-hydroxyfurfural from glucose catalyzed by ionic liquid [TMPDAPS]1,5-NS

[0166] Take glucose (100.5 mg) and ionic liquid [TMPDAPS]1,5-NS (201.5 mg), add 0.5 mL of saturated saline and 3 mL of tetrahydrofuran, and react with rapid stirring at 160 ° C for 3 hours. Then, cool the pressure bottle to room temperature, centrifuge the reaction solution to remove solid impurities, and measure 5-hydroxyfurfural (11.66 mg, 16.66%). The ionic liquid [TMPDAPS]1,5-NS can be recycled.

[0167] The above-mentioned embodiments are preferred embodiments, but the protection scope of the present invention is not limited thereto. Ordinary technicians in this field can easily understand the spirit of the present invention based on the above-mentioned embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for preparing 5-hydroxyfurfural from biomass based on the catalysis of tetramethylpropylenediamine acidic ionic liquid, characterized in that: Biomass, tetramethylpropylenediamine acidic ionic liquid, saturated sodium chloride solution and solvent are mixed and reacted at high temperature to prepare 5-hydroxyfurfural; The general structural formula of the tetramethylpropylenediamine acidic ionic liquid is shown in the following formula (I): Where R - Selected from F - 、Cl - Br - , I - 、HSO4 - 、H2PO4 - CF3SO3 - 、CH3SO3 - 、FeCl4 - 、AlCl4 - 、HSiO3 - 、H2PW 12 O 40 - 、 One or more of .

2. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 1, characterized in that: The mass ratio of biomass to tetramethylpropylenediamine-based acidic ionic liquid is 1:(0.1-5.0); The mass volume ratio of biomass to saturated sodium chloride solution is 100: (0.25-1.0) mg / mL.

3. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 1, characterized in that: The solvent is selected from one or more of r-valerolactone, tetrahydrofuran, methyltetrahydrofuran, acetone, and ethylene glycol dimethyl ether; The mass volume ratio of biomass to solvent is 100:(1-10) mg / mL.

4. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropanediamine acidic ionic liquid catalysis according to claim 1, characterized in that: The biomass is selected from glucose and / or starch.

5. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 1, characterized in that: The temperature of the high temperature reaction is not higher than 200° C., and the time is 1 to 5 hours.

6. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 1, characterized in that: The preparation method of the tetramethylpropylenediamine acidic ionic liquid is as follows: The intermediate, the Bronsted acid compound and water are mixed and reacted at 50-100° C. to obtain a tetramethylpropylenediamine-based acidic ionic liquid; The structural formula of the intermediate is as follows: The Bronsted acid compound is selected from HF, HCl, HI, H2SO4, H3PO4, CF3SO3H, CH3SO3H, FeCl3, AlCl3, H2SiO3, H3PW 12 O 40 、 One or more of .

7. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 6, characterized in that: The mass ratio of the intermediate, the Bronsted acid compound and water is 1:(0.1-5):(0.1-10).

8. The method for preparing 5-hydroxyfurfural from biomass based on the catalysis of tetramethylpropylenediamine acidic ionic liquid according to any one of claims 1 to 7, characterized in that: The biomass is selected from glucose; In the general structural formula of the tetramethylpropylenediamine acidic ionic liquid, R - Selected from Cl - and / or CH3SO3 - .

9. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropylenediamine acidic ionic liquid catalysis according to claim 8, characterized in that: The solvent is selected from one or more of r-valerolactone, methyltetrahydrofuran, and acetone; The mass volume ratio of glucose to solvent is 100:(3-6) mg / mL.

10. The method for preparing 5-hydroxyfurfural from biomass based on tetramethylpropanediamine-based acidic ionic liquid catalysis according to claim 8, characterized in that: The mass ratio of glucose to tetramethylpropylenediamine acidic ionic liquid is 1:(1.5-2.5); The mass volume ratio of glucose to saturated sodium chloride solution is 100:(0.5-0.75) mg / mL; The temperature of the high temperature reaction is 150-170° C., and the time is 1-4 hours.

Images