A reaction control phase transfer catalyst, a preparation method thereof and a method for catalytically synthesizing 2-pyrazoline
By preparing a reaction-controlled phase transfer catalyst, the problems of difficult catalyst separation and recovery and easy loss were solved, realizing the efficient and green synthesis of 2-pyrazoline. The catalyst can be reused, reducing the overall cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHENGZHOU ZHONGKE EMERGING IND TECH RES INST
- Filing Date
- 2024-10-29
- Publication Date
- 2026-06-02
AI Technical Summary
Existing catalysts are difficult to separate and recover during the synthesis of 2-pyrazoline, have poor reusability, and are prone to loss. Furthermore, traditional acid catalysts face challenges in terms of greening and energy conservation.
A reaction-controlled phase transfer catalyst is used. This catalyst is formed by mixing a bidentate nitrogen heterocyclic compound with an organic sulfonic acid. It is solid at room temperature and has dual acid centers of Brønsted acid and Lewis acid. It is formed through a proton transfer reaction, achieving liquid-solid self-separation, and catalyzing the synthesis of 2-pyrazoline.
It achieves efficient and green 2-pyrazoline synthesis with a ketone-azoline conversion rate of up to 90% and a 2-pyrazoline selectivity of up to 99%. The catalyst can be recycled with a high recovery rate, reducing the overall cost.
Smart Images
Figure CN119390692B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of the aerospace industry, and particularly relates to a reaction-controlled phase transfer catalyst, its preparation method, and a method for catalytic synthesis of 2-pyrazoline. Background Technology
[0002] High-energy fuels, as the core power source of engines, are crucial for the development of the aerospace field. Tensile ring hydrocarbon fuels possess advantages such as high density and high volumetric calorific value. Developing tensile ring hydrocarbon fuels is essential to meet the critical strategic needs of my country's new generation of manned launch vehicles and the enhanced capabilities of long-range unmanned aerial vehicles. This research can improve the propulsion speed requirements of advanced aircraft and extend the range of existing aircraft. Currently, there is an urgent need to overcome technical challenges such as catalyst conversion rate and selectivity, process optimization and scale-up, and efficient purification and quality control to develop core technologies for the green and efficient preparation of high-energy fuels. Currently, cyclopropyl liquid hydrocarbon fuels are mainly obtained through high-temperature denitrification of 2-pyrazoline, as shown in the following reaction equation:
[0003]
[0004] Currently, the traditional synthesis method for 2-pyrazoline is mainly the homogeneous acid-catalyzed ketazine isomerization cyclization method, but this method generates a large amount of acidic wastewater. In recent years, novel catalysts such as solid acids and ionic liquids have been reported. For example, patent publication number CN117753474A discloses a sulfonic acid solid acid catalyst and its preparation method, as well as a method for catalyzing the isomerization of ketazine to 2-pyrazoline. The solid acid catalyst mainly consists of methanesulfonic acid and amorphous silica support, and its main characteristic is a high Brønsted acid center. Another example is patent publication number CN118084789A, which discloses a method for synthesizing pyrazoline through the ketazine internal cyclization reaction catalyzed by zirconium salts, using zirconium salts as catalysts. However, these methods still suffer from drawbacks such as difficulty in separation and recovery, poor reusability, and easy loss. Summary of the Invention
[0005] To address the technical problems of difficult separation and recovery, poor reusability, and easy loss of solid catalysts, this invention proposes a reaction-controlled phase transfer catalyst, its preparation method, and a method for the catalytic synthesis of 2-pyrazoline. The reaction-controlled phase transfer catalyst is a type of unconventional ionic liquid that is solid at room temperature. It is applied for the first time to the catalytic synthesis of 2-pyrazoline. In this reaction, the novel reaction-controlled phase transfer catalyst exhibits a unique liquid-solid self-separation phenomenon, achieving enhanced coupling between reaction and separation, and guiding a highly efficient and green synthesis process. More importantly, it achieves stable precipitation with high recovery rate of the reaction-controlled phase transfer catalyst, realizing the invention's objective of catalyst reuse, and overcoming the problems of greening, energy saving, and low overall cost associated with traditional inorganic / organic acid catalysts and solid catalysts widely used in industry.
[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:
[0007] A method for preparing a reaction-controlled phase transfer catalyst includes the following steps: mixing and dissolving a bidentate nitrogen heterocyclic compound, an organic sulfonic acid, and a solvent, then reacting the mixture, and after the reaction is complete, rotary evaporation, washing to precipitate crystals, and drying to obtain the reaction-controlled phase transfer catalyst.
[0008] The bidentate nitrogen heterocyclic compound in step (1) is 1,10-o-phenanthroline, 2,2'-bipyridine, or 4,4'-bipyridine.
[0009] The organic sulfonic acid is any one of trifluoromethanesulfonic acid, methanesulfonic acid, and chlorosulfonic acid.
[0010] The solvent is an alcohol solvent; the alcohol solvent is any one of methanol, ethanol, isopropanol and n-propanol; the ratio of the alcohol solvent to the bidentate nitrogen heterocyclic compound is (0.1-1) L: 1 mol.
[0011] The molar ratio of the bidentate nitrogen heterocyclic compound to the organic sulfonic acid is 1:(2-1).
[0012] The reaction is carried out at a temperature of 25-80℃ for 6-24 hours.
[0013] Preferably, the reaction-controlled phase transfer catalyst has the structural formula shown in any one of formulas I-III:
[0014]
[0015] A method for synthesizing 2-pyrazoline using a reaction-controlled phase transfer catalyst includes the following steps: mixing a ketone azo compound with a reaction-controlled phase transfer catalyst, heating the mixture above the melting point of the reaction-controlled phase transfer catalyst, and reacting to obtain the 2-pyrazoline compound.
[0016] The reaction-controlled phase transfer catalyst is an unconventional ionic liquid that is solid at room temperature and has both Brønsted acid and Lewis acid dual acid centers. After the reaction is completed, the liquid and solid separate spontaneously.
[0017] The structural formula of the ketone azo compound is shown in Formula IV:
[0018]
[0019] The structural formula of the 2-pyrazoline compound is shown in Formula V:
[0020]
[0021] The reaction is carried out at a temperature of 90-105℃ for 2-8 hours.
[0022] The molar ratio of the ketone azo to the reaction-controlled phase transfer catalyst is (10:1)-(60:1).
[0023] The beneficial effects of this invention are as follows: The reaction-controlled phase transfer catalyst is an unconventional ionic liquid formed by a bidentate nitrogen heterocyclic compound and an organic sulfonic acid via a proton transfer reaction, possessing both Brønsted (B) and Lewis (L) acid centers, and existing as a solid at room temperature. Utilizing the dual active centers of the reaction-controlled phase transfer catalyst, highly efficient catalytic synthesis of pyrazolines is achieved, with a ketone-azoline conversion rate as high as 90% and a 2-pyrazoline selectivity as high as 99%. Simultaneously, due to its unique properties, the reaction-controlled phase transfer catalyst exhibits a unique liquid-solid self-separation phenomenon in the catalytic synthesis of 2-pyrazolines, achieving enhanced coupling of reaction and separation, and guiding a highly efficient and green synthesis process. More importantly, it achieves stable precipitation with high recovery rate of the reaction-controlled phase transfer catalyst, realizing the invention's objective of catalyst reuse, and overcoming the problems of greening, energy saving, and low overall cost associated with traditional inorganic / organic acid catalysts and solid catalysts widely used in industry. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a physical image of catalyst 1, which controls the phase transfer of the reaction.
[0026] Figure 2 This is a physical image of the reaction-controlled phase transfer catalyst 2.
[0027] Figure 3This is a physical image of the reaction-controlled phase transfer catalyst 3.
[0028] Figure 4 To illustrate the state changes of the reaction-controlling phase transfer catalyst 1 at the start, during, and after the reaction in Example 4.
[0029] Figure 5 The single-crystal analytical diagram of reaction-controlled phase transfer catalyst 1 is shown.
[0030] Figure 6 The image shows the Py-IR spectrum of catalyst 1, which controls the reaction phase transfer.
[0031] Figure 7 The Py-IR spectrum of reaction-controlled phase transfer catalyst 2 is shown.
[0032] Figure 8 The image shows the Py-IR spectrum of catalyst 3, which controls the phase transfer reaction. Detailed Implementation
[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0034] Example 1
[0035] A reaction-controlled phase transfer catalyst, with the following structural formula: This is designated as catalyst 1; the preparation method of catalyst 1 includes the following steps:
[0036] Weigh 0.1 mol of 1,10-o-phenanthroline and dissolve it in 100 mL of ethanol solution to form a homogeneous solution. Then, slowly add 0.2 mol of organic sulfonic acid to the ethanol solution and stir vigorously at room temperature for 30 min. Gradually raise the temperature to 60 °C and maintain it for 8 h. Rotary evaporate to completely remove ethanol, and wash repeatedly with toluene to remove unreacted raw materials until crystals precipitate. Vacuum dry and maintain at 80 °C for 12 h to obtain reaction-controlled phase transfer catalyst 1 (e.g., Figure 1 (As shown). Catalyst 1: 1 H NMR (500MHz, DMSO-d6) δ9.23 (dd, J=4.9, 1.5Hz, 1H), 9.00 (dd, J=8.2, 1.5Hz, 1H), 8.24 (s, 1H), 8.18 (dd, J=8.2, 4.9Hz, 1H), 2.50 (s, 3H); MS (ESI): m / z 181.08[C 12 H8N2–H]+ Anal.Calcd.for C 14 H 16 N2O6S2: C, 45.15; H, 4.33; N, 7.52. Found: C, 42.71; H, 4.71; N, 7.07.
[0037] Example 2
[0038] A reaction-controlled phase transfer catalyst, with the following structural formula: This is designated as catalyst 2; the preparation method of catalyst 2 includes the following steps:
[0039] Weigh 0.1 mol of 1,10-o-phenanthroline and dissolve it in 150 mL of ethanol solution to form a homogeneous solution. Then, slowly add 0.1 mol of organic sulfonic acid to the ethanol solution and stir vigorously at room temperature for 30 min. Gradually raise the temperature to 60 °C and maintain it for 8 h. Rotary evaporate to completely remove ethanol, and wash repeatedly with toluene to remove unreacted raw materials until crystals precipitate. Vacuum dry and maintain at 80 °C for 12 h to obtain reaction-controlled phase transfer catalyst 2 (e.g. Figure 2 (As shown). Catalyst 2: 1 H NMR (500MHz, DMSO-d6) δ9.25 (dd, J=4.9, 1.6Hz, 1H), 9.01 (dd, J=8.2, 1.6Hz, 1H), 8.27 (s, 1H), 8.19 (dd, J=8.2, 4.9Hz, 1H), 2.41 (s, 1H); MS (ESI): m / z 181.08[C 12 H8N2–H] + Anal.Calcd.for C 13 H 12 N2O3S:C,56.51;H,4.38;N,10.14.Found:C,56.14;H,4.33;N,10.19.
[0040] Example 3
[0041] A reaction-controlled phase transfer catalyst, with the following structural formula: This is designated as catalyst 3; the preparation method of catalyst 3 includes the following steps:
[0042] Weigh 0.1 mol of 2,2'-bipyridine and dissolve it in 50 mL of ethanol solution to form a homogeneous solution. Then, slowly add 0.2 mol of organic sulfonic acid to the ethanol solution and stir vigorously at room temperature for 30 min. Gradually raise the temperature to 60 °C and maintain it for 8 h. Rotary evaporate to completely remove ethanol, and wash repeatedly with toluene to remove unreacted raw materials until crystals precipitate. Vacuum dry and maintain at 80 °C for 12 h to obtain reaction-controlled phase transfer catalyst 3 ((e.g. Figure 3 (As shown) Catalyst 3: 1H NMR (300MHz, DMSO-d6) d (ppm): 11.27 (OH,s), 8.89 (1H,d), 8.87 (1H,d), 8.66 (1H,d), 8.63 (1H,d), 8.40 (2H,t), 7.87 (1H,t), 7.86 (1H,t). 13C NMR (75MHz, DMSO-d6) d (ppm): 147.86, 147.04, 143.38, 127.65, 124.22. MS (ESI): m / z 157.08 Anal.Calcd.forC10H12N2O8S2:C,34.09;H,3.41;N,7.95.Found:C,34.10;H,3.43;N,7.92.
[0043] Example 4
[0044] A reaction-controlled phase transfer catalyst, the preparation method of which includes the following steps:
[0045] Weigh 0.1 mol of 4,4'-bipyridine and dissolve it in 10 ml of isopropanol solution to form a homogeneous solution. Then, slowly add 0.15 mol of trifluoromethanesulfonic acid to the isopropanol solution and stir vigorously at 25 °C for 30 min, and maintain for 24 h. Rotary evaporate to completely remove ethanol and wash repeatedly with toluene to remove unreacted raw materials until crystals precipitate. Dry under vacuum and maintain at 80 °C for 12 h to obtain the reaction-controlled phase transfer catalyst.
[0046] Example 5
[0047] A reaction-controlled phase transfer catalyst, the preparation method of which includes the following steps:
[0048] Weigh 0.1 mol of 1,10-o-phenanthroline and dissolve it in 100 ml of ethanol solution to form a homogeneous solution. Then, slowly add 0.15 mol of methanesulfonic acid to the ethanol solution, stir vigorously at 25°C for 30 min, gradually raise the temperature to 80°C and maintain it for 6 h. Remove the ethanol completely by rotary evaporation, and wash repeatedly with toluene to remove unreacted raw materials until crystals precipitate. Dry under vacuum and maintain at 80°C for 12 h to obtain the reaction-controlled phase transfer catalyst.
[0049] The reaction-controlled phase transfer catalysts used in the following application examples are catalysts 1-3 prepared in Examples 1-3.
[0050] Application Example 1
[0051] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of acetone ketone to yield 3,5,5-trimethyl-2-pyrazoline, the steps of which are as follows:
[0052] 1) Add 0.4 mol of acetone ketazine (44.8 g) to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0053] 2) Next, add catalyst 1 (0.01 mol, 3.72 g);
[0054] 3) Start stirring at 200 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0055] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0056] Application Example 2
[0057] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of butanone to yield 3,5-diethyl-5-methyl-2-pyrazoline, the steps of which are as follows:
[0058] 1) Add 0.4 mol, 56 g of butanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0059] 2) Next, add catalyst 1 (0.01 mol, 3.72 g);
[0060] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0061] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0062] Application Example 3
[0063] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of 2-pentanone to yield 3,5-dipropyl-5-methyl-2-pyrazoline, the steps of which are as follows:
[0064] 1) Add 0.4 mol (67.2 g) of 2-pentanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0065] 2) Next, add catalyst 1 (0.01 mol, 3.72 g);
[0066] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0067] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0068] Application Example 4
[0069] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of 2-octanone to yield 3,5-dihexyl-5-methyl-4,5-dihydro-1H-pyrazole, with the following specific steps:
[0070] 1) Add 0.2 mol (50.4 g) of 2-octanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0071] 2) Next, add catalyst 1 (0.005 mol, 1.86 g);
[0072] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0073] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0074] Figure 4 The figure shows the state changes of the reaction-controlled phase transfer catalyst 1 at the beginning, during and after the reaction. As can be seen from the figure, the reaction-controlled phase transfer catalyst 1 is initially solid in 2-octanone ketone nitrogen. As the temperature increases, the reaction-controlled phase transfer catalyst 1 dissolves and participates in the catalytic reaction. After the reaction is completed, the reaction solution returns to room temperature, and the reaction-controlled phase transfer catalyst 1 precipitates out again.
[0075] Application Example 5
[0076] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of cyclopropyl ketone to yield 5-methyl-3,5-dicyclopropylpyrazoline, the steps of which are as follows:
[0077] 1) Add 0.3 mol (49.2 g) of cyclopropyl ketone azide to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment;
[0078] 2) Next, add catalyst 1 (0.0075 mol, 2.79 g);
[0079] 3) Start stirring at 250 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0080] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0081] Application Example 6
[0082] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of 2-octanone to yield 3,5-dihexyl-5-methyl-4,5-dihydro-1H-pyrazole, the steps of which are as follows:
[0083] 1) Add 0.2 mol (50.4 g) of 2-octanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0084] 2) Next, add catalyst 1 (0.02 mol, 7.44 g);
[0085] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 90°C. React for 8 hours.
[0086] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0087] Application Example 7
[0088] A reaction-controlled phase transfer catalyst 1 catalyzes the azo-isomerization cyclization of 2-octanone to yield 3,5-dihexyl-5-methyl-4,5-dihydro-1H-pyrazole, the steps of which are as follows:
[0089] 1) Add 0.2 mol (50.4 g) of 2-octanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0090] 2) Next, add catalyst 1 (0.0025 mol, 0.93 g);
[0091] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 105℃. React for 8 hours.
[0092] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0093] Application Example 8
[0094] A reaction-controlled phase transfer catalyst 2 catalyzes the azo-isomerization cyclization of 2-octanone to give 3,5-dihexyl-5-methyl-4,5-dihydro-1H-pyrazole, the steps of which are as follows:
[0095] 1) Add 0.2 mol (50.4 g) of 2-octanone ketazine to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment.
[0096] 2) Next, add catalyst 2 (0.005 mol, 1.38 g);
[0097] 3) Start stirring at 300 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0098] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0099] Application Example 9
[0100] A reaction-controlled phase transfer catalyst 3 catalyzes the azo-isomerization cyclization of cyclopropyl ketone to yield 5-methyl-3,5-dicyclopropylpyrazoline, the steps of which are as follows:
[0101] 1) Add 0.3 mol (49.2 g) of cyclopropyl ketone azide to a 250 mL three-necked flask and continuously purge with nitrogen gas to keep the system in an inert environment;
[0102] 2) Next, add catalyst 3 (0.0075 mol, 1.89 g);
[0103] 3) Start stirring at 250 rpm, turn on heating, and slowly raise the temperature to 100℃. React for 8 hours.
[0104] 4) Cool to room temperature, use internal standard method, and perform quantitative analysis with Agilent GC-8890.
[0105] Recovery of reaction-controlled phase transfer catalysts 1-9
[0106] The recovery of reaction-controlled phase transfer catalysts 1-9 is carried out as follows: After the reaction in Application Examples 1-9 is completed, the catalyst and the reaction liquid are allowed to cool to room temperature, and the catalyst and the reaction liquid achieve liquid-solid self-separation. The oil layer is filtered out, and the catalyst can be used directly without further treatment.
[0107] Table 1. Experimental data from Application Examples 1-9
[0108]
[0109]
[0110] The reaction-controlled phase transfer catalyst 1-3 was recycled. The reaction-controlled phase transfer catalyst 1-3 recovered from Application Examples 4, 8 and 9 was used under the same conditions as the corresponding application examples (including reaction temperature, molar ratio, stirring speed, reaction time, etc.) to repeat the catalytic experiment 5 times. The results are shown in Table 2.
[0111] Table 2 shows the repeated experimental conditions for Examples 4, 8, and 9 (reaction control phase transfer catalysts 1-3).
[0112]
[0113] The catalytic efficiency and versatility of the catalysts in Application Examples 1-9 are tested, as shown in Table 1. The results indicate that the novel reaction-controlled phase transfer catalysts 1-3 prepared according to this invention have good catalytic performance, providing a new catalyst design approach for pyrazoline synthesis. Table 2 shows the reusability evaluation of the catalysts in Application Examples 4, 8, and 9. The results show that the novel reaction-controlled phase transfer catalysts 1-3 still maintain high catalytic activity after three uses.
[0114] Further comparison revealed that the novel reaction-controlled phase transfer catalyst 1 exhibited superior catalytic performance, prompting further characterization and analysis. The crystal structure parameters of catalyst 1 were obtained using X-ray single-crystal diffraction. Figure 5 The results show that catalyst 1 has an orthorhombic crystal system, space group Pna21, and cell parameters [missing information]. a=90°, β=90°, γ=90°, Dc = 1.513Mg / m 3 Z = 4. Meanwhile, analysis of the ball-and-stick diagram and crystal structure shows that the molecule of catalyst 1 is not entirely composed of positively charged [C] atoms. 12 H8N2–H] + and negatively charged [CH3SO3] - The ionic compound, unlike traditional ionic liquids, contains both an NH covalent bond (similar to that of an ionic liquid) and an N…H hydrogen bond. This means that the first CH3SO3H reacts with one of the N sites of the cation to form a stable NH covalent bond. The second CH3SO3H, due to the weakened basicity of the second N site and unavoidable steric hindrance, can only connect with the second N phase via a hydrogen bond. The hydrogen bond prevents the CH3SO3H from easily detaching from the cation, but ensures that the resulting complex releases a significant amount of H+. + This explains why catalyst 1 exhibits significantly higher catalytic activity than catalyst 2. Conversely, catalyst 3, with its higher symmetry, corresponds to lower acidity, which is another reason why its catalytic activity is lower than that of catalyst 1.
[0115] Furthermore, pyridine infrared spectroscopy reveals that catalysts 1-3 all possess dual catalytic active sites (L acid sites and Brønsted acid sites), such as... Figure 6-8 .
[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for the reaction-controlled phase transfer catalyst-catalyzed synthesis of 2-pyrazoline, characterized in that, The steps are as follows: ketone azo and reaction-controlled phase transfer catalyst are mixed and heated to above the melting point of the reaction-controlled phase transfer catalyst to prepare 2-pyrazoline compound; The structural formula of the ketone azide is shown in Formula IV: Formula IV; The structural formula of the 2-pyrazoline compound is shown in Formula V: Formula V; The structural formula of the reaction-controlled phase transfer catalyst is shown in any one of formulas I-III: , , .
2. The method for the reaction-controlled phase transfer catalyst-catalyzed synthesis of 2-pyrazoline according to claim 1, characterized in that, The temperature for heating to above the melting point of the reaction-controlling phase transfer catalyst is 90-105℃, and the time is 2-8 hours.
3. The method for the reaction-controlled phase transfer catalyst-catalyzed synthesis of 2-pyrazoline according to claim 1, characterized in that, The molar ratio of the ketone azo to the reaction-controlled phase transfer catalyst is (10:1)-(60:1).