Functional ionic liquid catalyst and application thereof
By using a functional ionic liquid catalyst to catalyze the carboxylation reaction between CO2 and 2-aminobenzonitrile under solvent-free, metal-free and halogen-free conditions, the problems of harsh reaction conditions and difficult catalyst separation in the prior art were solved, and the efficient and environmentally friendly preparation of quinazoline-2,4(1H,3H)-dione was achieved.
Patent Information
- Application Number
- CN202411575948.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-06
- Publication Date
- 2025-03-07
AI Technical Summary
The prior art has problems such as harsh reaction conditions, difficult solvent use, and difficult catalyst separation in the preparation of quinazoline-2,4(1H,3H)-dione when catalyzing the CO2 carboxylation reaction, and it is difficult to achieve efficient catalysis under mild conditions.
A functional ionic liquid catalyst is used, which is prepared by a one-step neutralization of acid-base reaction by a one-step neutralization of CO2 and 2-aminobenzonitrile under solvent-free, metal-free and halogen-free conditions.
The carboxylation reaction between CO2 and 2-aminobenzonitrile is efficiently catalyzed under mild conditions. The yield of the product quinazoline-2,4(1H,3H)-dione is as high as 97%. The catalyst has good thermal stability, low cost, reusable, and does not contain halides, reducing corrosion to metal equipment.
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Figure CN119565667A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalysts, in particular to a functional ionic liquid catalyst and application thereof. Background Art
[0002] With the rapid development of industry, the consumption of fossil energy has also increased rapidly. The use of a large amount of fossil fuels has led to a rapid increase in the emission of CO2, a highly heat-absorbing gas in the atmosphere, exacerbating the "greenhouse effect". How to reduce the concentration of CO2 in the atmosphere has become a common concern of countries around the world. In addition, as a C1 resource with abundant reserves, low cost, safety, non-toxicity and renewable, CO2 has very important research value and significance in converting it into high-value-added chemicals. So far, the industry has developed a variety of CO2 chemical conversion pathways, which can produce a variety of valuable products, such as formic acid, methanol, cyclic carbonates, dimethyl carbonate, quinazoline-2,4(1H,3H)-dione, carbamates and polycarbonates.
[0003] Quinazoline-2,4(1H,3H)-dione is widely used in the field of pharmaceutical intermediates. It is an important intermediate for the production of drugs including antihypertensive, antilipidemic, anticancer, antidepressant, antioxidant, and anti-inflammatory drugs. It has attracted attention in the field of organic and medicinal chemistry. Traditional synthetic routes such as o-aminobenzoic acid, o-aminobenzamide and phosgene, and o-aminobenzamide and CO have problems such as low reaction safety, serious environmental pollution, and harsh reaction conditions. Therefore, the green route of synthesizing quinazoline-2,4(1H,3H)-dione using CO2 and 2-aminobenzonitrile has attracted widespread attention. At present, a variety of heterogeneous and homogeneous catalysts have been used. In heterogeneous reactions, organic solvents such as DMSO, DMF or toluene need to be introduced to ensure sufficient gas-liquid-solid reaction. This system has problems such as difficulty in separating the solid product and the catalyst after the reaction and the introduction of additional organic solvents.
[0004] Therefore, at this stage, it is of great practical significance to develop a homogeneous catalyst that can catalyze the CO2 carboxylation reaction to prepare quinazoline-2,4(1H,3H)-dione under mild conditions. Summary of the invention
[0005] In view of the deficiencies in the prior art, the present invention provides a functional ionic liquid catalyst with good thermal stability and high catalytic efficiency, and is used for catalyzing the CO2 carboxylation reaction to prepare quinazoline-2,4(1H,3H)-dione. The reaction is carried out under green conditions without solvent, metal or halogen, with mild reaction conditions, low catalyst cost, good thermal stability, repeatable recycling and good substrate applicability.
[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: a functional ionic liquid catalyst, comprising a cation and an anion, wherein the cation is at least one of 1,8-diazacyclo[5,4,0]undecene, choline hydroxide, and 1,1,3,3-tetramethylguanidine, and the anion is at least one of pyrrole and 2-hydroxypyridine.
[0007] Preferably, the molar ratio of the cation to the anion is 0.8-1.2:1-1.5.
[0008] Preferably, the cation is 1,1,3,3-tetramethylguanidine.
[0009] Preferably, the anion is 2-hydroxypyridine.
[0010] Preferably, the preparation method comprises the following steps: adding 8-12 mmol of cation and 10-15 mmol of anion to a reaction bottle, and then adding 15-30 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically in a N2 protective atmosphere at 30-50°C for 3-6 hours, the obtained light yellow viscous liquid is washed several times with methyl tert-butyl ether to remove unreacted products, and then the light yellow viscous liquid is evaporated with a rotary evaporator to remove the solvent, and finally vacuum dried to obtain an ionic liquid catalyst.
[0011] Preferably, the vacuum drying temperature is 50° C. and the time is 24 hours.
[0012] The present invention also provides the use of the functional ionic liquid catalyst in catalyzing the carboxylation reaction of CO2 and 2-aminobenzonitrile and its derivatives. The structural formula of the 2-aminobenzonitrile and its derivatives is as follows: , wherein R is at least one of CH3, F, Cl, Br, and I; The carboxylation reaction equation of CO2 with 2-aminobenzonitrile and its derivatives is as follows: .
[0013] Preferably, the specific steps of the carboxylation reaction of CO2 with 2-aminobenzonitrile and its derivatives are as follows: a certain proportion of the functional ionic liquid catalyst described in any one of claims 1 to 6 and 2-aminobenzonitrile and its derivatives are added to a reaction tube with magnetic stirring, CO2 gas is used to replace the air in the system several times and the reaction is carried out in an oil bath, CO2 gas is injected into the reaction tube through a balloon during the entire reaction process, and after the reaction is completed, deionized water and methyl tert-butyl ether are used to wash several times respectively, and the obtained white solid is vacuum dried at 50°C for 12-18h.
[0014] Preferably, the reaction time of the carboxylation reaction is 1-8h, the reaction temperature is 50-100°C, the reaction pressure is 0.5-2MPa, and the molar ratio of the functional ionic liquid catalyst to 2-aminobenzonitrile and its derivatives is 0.25-3.
[0015] The present invention discloses a functional ionic liquid catalyst, which has the following beneficial effects: 1. The functional ionic liquid catalyst of the present invention is prepared by a one-step neutralization acid-base reaction, and the synthesis process is simple. The prepared functional ionic liquid catalyst does not contain halide components, which reduces corrosion to metal equipment and prolongs the service life of the equipment.
[0016] 2. The functional ionic liquid catalyst of the present invention is both a solvent and a catalyst in the carboxylation reaction of CO2 and 2-aminobenzonitrile, eliminating the use of a reaction solvent and simplifying the separation and purification process of the product. The carboxylation reaction of CO2 can be carried out at normal pressure and relatively low temperature, with mild catalytic conditions and is green and pollution-free.
[0017] 3. The functional ionic liquid of the present invention has the advantages of high catalytic activity, good thermal stability, and reusability as a catalyst. The conversion rate of the carboxylation reaction of catalyzed CO2 and 2-aminobenzonitrile is high, and the yield of quinazoline-2,4(1H,3H)-dione is as high as 97%.
[0018] 4. The functional ionic liquid catalyst of the present invention catalyzes the carboxylation reaction of CO2 and 2-aminobenzonitrile derivatives. [TMG][2-OPy] catalyzes the meta- or para-position substrate to obtain a yield of 95% or even higher, further verifying that the catalyst has a wide range of substrate applicability. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is [TMG][2-OPy] in Example 1 of the present invention 1 H NMR spectrum.
[0020] Figure 2 is [TMG][2-OPy] in Example 1 of the present invention 13 C NMR spectrum.
[0021] Figure 3 is quinazoline-2,4(1H,3H)-dione in Example 7 of the present invention 1 H NMR spectrum.
[0022] Figure 4 is quinazoline-2,4(1H,3H)-dione in Example 7 of the present invention 13 C NMR spectrum.
[0023] Figure 5This is a test graph of the cyclic stability of [TMG][2-OPy] in Example 13 of the present invention. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] Example 1: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of 1,1,3,3-tetramethylguanidine [TMG] and 10 mmol of 2-hydroxypyridine [2-OPy] to a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45° C. for 4 h in a N2 protective atmosphere, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted substances, and then the light yellow viscous liquid is evaporated with a rotary evaporator to remove the solvent, and finally vacuum dried at 50° C. for 24 h to obtain an ionic liquid [TMG][2-OPy], [TMG][2-OPy] 1 H NMR spectrum Figure 1 As shown, 13 C NMR spectrum Figure 2 shown.
[0026] Example 2: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of 1,8-diazacyclo[5,4,0]undecene[DBU] and 10 mmol of 2-hydroxypyridine[2-OPy] to a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45° C. in a N2 protective atmosphere for 4 hours, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted materials, and then the light yellow viscous liquid is evaporated with a rotary evaporator to remove the solvent, and finally vacuum dried at 50° C. for 24 hours to obtain the ionic liquid [DBU][2-OPy].
[0027] Example 3: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of choline hydroxide [Ch] and 10 mmol of 2-hydroxypyridine [2-OPy] to a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45 ° C in a N2 protective atmosphere for 4 hours, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted materials, and then the light yellow viscous liquid is evaporated by a rotary evaporator to remove the solvent, and finally vacuum dried at 50 ° C for 24 hours to obtain the ionic liquid [Ch][2-OPy].
[0028] Example 4: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of 1,1,3,3-tetramethylguanidine [TMG] and 10 mmol of pyrrole [Py] to a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45 ° C in a N2 protective atmosphere for 4 hours, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted materials, and then the light yellow viscous liquid is evaporated with a rotary evaporator to remove the solvent, and finally vacuum dried at 50 ° C for 24 hours to obtain the ionic liquid [TMG][Py].
[0029] Example 5: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of 1,8-diazacyclo[5,4,0]undecene[DBU] and 10 mmol of pyrrole[Py] into a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45°C in a N2 protective atmosphere for 4 hours, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted materials, and then the light yellow viscous liquid is evaporated with a rotary evaporator to remove the solvent, and finally vacuum dried at 50°C for 24 hours to obtain the ionic liquid[DBU][Py].
[0030] Example 6: A method for preparing a functional ionic liquid catalyst comprises the following steps: adding 10 mmol of choline hydroxide [Ch] and 10 mmol of pyrrole [Py] to a 100 ml Schlenk reaction bottle, and then adding 20 ml of anhydrous ethanol to fully dissolve them, the reaction solution is stirred magnetically at 45 ° C in a N2 protective atmosphere for 4 hours, the obtained light yellow viscous liquid is washed three times with methyl tert-butyl ether to remove unreacted materials, and then the light yellow viscous liquid is evaporated by a rotary evaporator to remove the solvent, and finally vacuum dried at 50 ° C for 24 hours to obtain the ionic liquid [Ch][Py].
[0031] Example 7: A carboxylation reaction of CO2 and 2-aminobenzonitrile, the specific steps are as follows: 2 mmol of the ionic liquid [TMG][2-OPy] obtained in Example 1 and 1 mmol of 2-aminobenzonitrile are added to a Schlenk reaction tube with magnetic stirring, and the air in the reaction tube is replaced with CO2 using a double-row tube before the reaction. The operation is repeated 3 times, and the reaction is carried out in an oil bath at 90°C for 8 hours. During the entire reaction process, CO2 gas is injected into the reaction tube through a balloon. After the reaction, the solid is washed three times with deionized water and methyl tert-butyl ether respectively, and the obtained white solid is vacuum dried at 50°C for 18 hours. The yield of the product quinazoline-2,4(1H,3H)-dione was determined to be 97% by weighing method (analytical balance, accuracy ±0.001 g). The product quinazoline-2,4(1H,3H)-dione 1 H NMR spectrum Figure 3 As shown, 13 C NMR spectrum Figure 4 shown.
[0032] Example 8: Different from Example 7, under the premise of other reaction conditions being the same, the catalytic effects of different functional ionic liquid catalysts on the reaction of CO2 and 2-aminobenzonitrile were evaluated, see Table 1. + and Ch + As cation, 2-OPy - When [TMG][2-OPy] was used as anion, the corresponding yields were 78% and 58%, respectively. In comparison, the yield was 97% when [TMG][2-OPy] was selected as the catalyst. - With 2-OPy - ) on catalytic performance. Combined with pH value, it can be seen that the reaction activity of catalysts containing the same cation is positively correlated with alkalinity, while the activity of catalysts containing different cations has nothing to do with alkalinity. Comparative experiments show that the reaction of CO2 with 2-aminobenzonitrile is determined by the ionic structure of the catalyst and the pH value.
[0033] Table 1 Catalytic effect of different functional ionic liquid catalysts on the reaction of CO2 and 2-aminobenzonitrile
[0034] Example 9: Different from Example 7, under the premise that other reaction conditions are the same, the catalytic effect of the functional ionic liquid catalyst [TMG][2-OPy] on the reaction of CO2 and 2-aminobenzonitrile at different reaction times was evaluated, refer to Table 2.
[0035] Table 2: Catalytic effect of [TMG][2-OPy] on the reaction of CO2 and 2-aminobenzonitrile at different reaction times
[0036] Example 10: Different from Example 7, under the premise that other reaction conditions are the same, the catalytic effect of the functional ionic liquid catalyst [TMG][2-OPy] on the reaction of CO2 and 2-aminobenzonitrile at different reaction temperatures was evaluated, refer to Table 3.
[0037] Table 3: Catalytic effect of [TMG][2-OPy] on the reaction of CO2 and 2-aminobenzonitrile at different reaction temperatures
[0038] Example 11: Different from Example 7, under the premise that other reaction conditions are the same, the catalytic effect of the functional ionic liquid catalyst [TMG][2-OPy] on the reaction of CO2 and 2-aminobenzonitrile at different reaction pressures at 30°C was evaluated. The pressure experiment was carried out in a 25ml stainless steel reactor equipped with a Teflon liner, refer to Table 4.
[0039] Table 4: Catalytic effect of [TMG][2-OPy] on the reaction of CO2 with 2-aminobenzonitrile at different reaction pressures at 30°C
[0040] Example 12: Different from Example 7, under the premise that other reaction conditions are the same, the effect of the molar ratio of the functional ionic liquid catalyst [TMG][2-OPy] to 2-aminobenzonitrile on the catalytic effect is evaluated, refer to Table 5.
[0041] Table 5 Effect of the molar ratio of [TMG][2-OPy] to 2-aminobenzonitrile on the catalytic effect
[0042] Example 13: Different from Example 7, 6 cycles were conducted under the same reaction conditions. After each cycle, a certain amount of deionized water was added to the reaction system to separate the catalyst from the system. The water was removed by a rotary evaporator and the recovered catalyst was dried at 50°C in vacuum for 24 h for the next cycle test. The results are shown in Table 6. The cycle stability test of [TMG][2-OPy] is shown in Figure 6. Figure 5 shown.
[0043] Table 6 Results of 6-cycle experiments
[0044] Example 14: Different from Example 7, under the premise of completely identical reaction conditions, a series of 2-aminobenzonitrile derivatives containing halogenated groups and methyl groups were selected to study the substrate applicability of [TMG][2-OPy].
[0045] Referring to Table 7, the experimental results show that [TMG][2-OPy] can obtain 95% or even higher yields for meta- or para-substrates, while the yields for ortho-substituted substrates are generally lower (70-80%). Substrate expansion experiments have shown that [TMG][2-OPy] exhibits acceptable to excellent catalytic effects on substrates with different groups.
[0046] Table 7 Applicability of [TMG][2-OPy] to substrates with different groups
[0047] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A functional ionic liquid catalyst, characterized in that: The invention comprises a cation and an anion, wherein the cation is at least one of 1,8-diazacyclo[5,4,0]undecene, choline hydroxide and 1,1,3,3-tetramethylguanidine, and the anion is at least one of pyrrole and 2-hydroxypyridine.
2. The functional ionic liquid catalyst according to claim 1, characterized in that The molar ratio of the cation to the anion is 0.8-1.2:1-1.
5.
3. The functional ionic liquid catalyst according to claim 1, characterized in that The cation is 1,1,3,3-tetramethylguanidine.
4. The functional ionic liquid catalyst according to claim 1, characterized in that The anion is 2-hydroxypyridine.
5. The functional ionic liquid catalyst according to claim 1, characterized in that: The preparation method comprises the following steps: adding 8-12 mmol of cations and 10-15 mmol of anions into a reaction bottle, and then adding 15-30 ml of anhydrous ethanol to fully dissolve the cations, and reacting the reaction solution under N2 protective atmosphere at 30-50° C. with magnetic stirring for 3-6 hours, washing the obtained light yellow viscous liquid with methyl tert-butyl ether for several times to remove unreacted substances, evaporating the light yellow viscous liquid to remove the solvent, and finally vacuum drying to obtain an ionic liquid catalyst.
6. The functional ionic liquid catalyst according to claim 5, characterized in that The vacuum drying temperature is 50° C. and the time is 24 h.
7. Use of the functional ionic liquid catalyst according to any one of claims 1 to 6 in catalyzing the carboxylation reaction of CO2 with 2-aminobenzonitrile and its derivatives, characterized in that: The structural formula of the 2-aminobenzonitrile and its derivatives is as follows: , wherein R is at least one of CH3, F, Cl, Br, and I; The carboxylation reaction equation of CO2 with 2-aminobenzonitrile and its derivatives is as follows: 。 8. The use according to claim 7, characterized in that: The specific steps of the carboxylation reaction of CO2 with 2-aminobenzonitrile and its derivatives are as follows: a certain proportion of the functional ionic liquid catalyst described in any one of claims 1 to 6 and 2-aminobenzonitrile and its derivatives are added to a reaction tube with magnetic stirring, CO2 gas is used to replace the air in the system several times and the reaction is carried out in an oil bath pot. After the reaction is completed, it is washed several times with deionized water and methyl tert-butyl ether respectively, and the obtained white solid is vacuum dried at 50°C for 12-18h.
9. The use according to claim 8, characterized in that: The reaction time of the carboxylation reaction is 1-8 hours, the reaction temperature is 50-100° C., the reaction pressure is 0.5-2 MPa, and the molar ratio of the functional ionic liquid catalyst to 2-aminobenzonitrile and its derivatives is 0.25-3.