Catalyst for synthesizing oxasulfuron, preparation method thereof and synthesis method of oxasulfuron

Abstract

The present application provides a catalyst for synthesizing pyroxasulfone, a preparation method thereof, and a synthesis method of pyroxasulfone. The catalyst for synthesizing pyroxasulfone provided by the present application comprises a silica support with three-dimensional dendritic pores inside, the silica support is loaded with a main active component V and an auxiliary active component M, M comprises at least one of Mo, Ce and Ti, and the specific surface area of the catalyst is 650-750 m2 / g, the total pore volume is 0.8-1.3 m3 / g, and the average pore diameter is 5-10 nm. The catalyst provided by the present application uses silica with three-dimensional dendritic pores inside as the support, and introduces the main active component V and the auxiliary active component M to cooperate with each other, which is used in the synthesis of pyroxasulfone. The raw material conversion rate reaches 100%, the product purity ≥90%, effectively reducing the preparation cost and post-treatment difficulty of pyroxasulfone, and having broad application prospects.

Description

Technical Field

[0001] The present application relates to the technical field of organic synthesis, and more particularly, to a catalyst for synthesizing pyroxasulfone, a preparation method thereof, and a synthesis method of pyroxasulfone. Background Art

[0002] Pyroxasulfone is a herbicide jointly developed by Nippon Soda Co., Ltd. and Anahara Chemical Co., Ltd. Its common English name is Pyroxasulfone, and its chemical name is 3 - [5 - (difluoromethoxy) - 1 - methyl - 3 - (trifluoromethyl)pyrazol - 4 - yl]methylsulfonyl] - 4,5 - dihydro - 5,5 - dimethyl - 1,2 - isoxazole. Although the reported previous synthetic routes are slightly different, in the existing disclosed preparation methods, it is ultimately necessary to oxidize a thioether intermediate to obtain pyroxasulfone. Therefore, it is particularly urgent to synthesize a catalyst with high activity, long life, high selectivity, and continuous production.

[0003] The main catalysts for oxidizing the existing thioether intermediate to prepare pyroxasulfone are sodium tungstate, tungsten oxide, ammonium molybdate, inorganic acid, ionic liquid, etc. However, in the homogeneous reaction system using sodium tungstate as a catalyst, the heat release of the reaction is large and the process risk is high; in the batch process using sodium tungstate or ammonium molybdate as a catalyst, limited by the heat transfer and mass transfer of the batch equipment itself, the reaction time is long and the reaction effect is poor; using inorganic acid or ionic liquid as a catalyst has a high cost, and cannot be recycled, resulting in a high post - treatment cost.

[0004] In view of this, the present application is specifically proposed. Summary of the Invention

[0005] The main purpose of the present application is to provide a catalyst for synthesizing pyroxasulfone, a preparation method thereof, and a synthesis method of pyroxasulfone, so as to solve at least one of the problems of high process risk, long reaction time, poor reaction effect, high cost, and complex post - treatment in the prior art when using sodium tungstate, tungsten oxide, ammonium molybdate, inorganic acid, or ionic liquid as a catalyst to oxidize a thioether intermediate to prepare pyroxasulfone.

[0006] To achieve the above object, according to one aspect of the present application, a catalyst for synthesizing pyroxasulfone is provided. The catalyst includes a silica support having three - dimensional dendritic pores inside, and the silica support is loaded with a main active component V and an auxiliary active component M. Wherein, M includes at least one of Mo, Ce, and Ti, and the specific surface area of the catalyst is 650 - 750 m 2 / g, the total pore volume is 0.8 - 1.3 m 3 / g, and the average pore diameter is 5 - 10 nm.

[0007] Further, M is Ce. In the catalyst, the molar ratio of Si, V, and Ce is 1: (0.2 - 0.3): (0.02 - 0.03).

[0008] Further, M is Mo. In the catalyst, the molar ratio of Si, V, and Mo is 1: (0.2 - 0.3): (0.01 - 0.02).

[0009] Further, M is Ti. In the catalyst, the molar ratio of Si, V, and Ti is 1: (0.2 - 0.3): (0.01 - 0.03).

[0010] Further, M includes Mo and Ti. In the catalyst, the molar ratio of Si, V, Mo, and Ti is 1: (0.2 - 0.3): (0.01 - 0.02): (0.01 - 0.03).

[0011] Further, M includes Ce, Mo, and Ti. In the catalyst, the molar ratio of Si, V, Ce, Mo, and Ti is 1: (0.2 - 0.3): (0.02 - 0.03): (0.01 - 0.02): (0.01 - 0.03).

[0012] Further, the catalyst is granular, and its particle size is 10 - 20 mesh.

[0013] According to the second aspect of the present application, a preparation method of the above catalyst for synthesizing sulfentrazone is provided. The preparation method includes the following steps: Step S1, preparing a silica carrier with three-dimensional dendritic pores; Step S2, dispersing the silica carrier in an organic alcohol and adding an alkaline solution to adjust the pH to obtain a silica suspension with a pH of 10 - 11; Step S3, adding a V source and an M source to the silica suspension so that V and M are loaded on the silica carrier, removing the solvent to obtain a catalyst precursor; Step S4, performing a first calcination on the catalyst precursor to obtain the catalyst for synthesizing sulfentrazone.

[0014] Further, Step S1 includes: Step S11, dispersing a template agent, a surfactant, and an acidic solution in water to obtain Solution A with a pH of 0.5 - 1; Step S12, sequentially adding an organic solvent and an organosilicon source to Solution A to obtain Solution B; Step S13, transferring Solution B to a reaction kettle for crystallization reaction to obtain a silica carrier precursor; Step S14, performing a second calcination on the silica carrier precursor to obtain the silica carrier.

[0015] Further, the template agent is selected from at least one of ammonium D,L-tartrate, pyrrolidone, cyclohexylamine, and piperidine.

[0016] Further, the surfactant is selected from at least one of cetyltrimethylammonium bromide, cetylpyridinium bromide, and Tween 80.

[0017] Further, the mass ratio of the template agent to the surfactant is (2 - 3):(2 - 3).

[0018] Further, the acidic solution is selected from at least one of hydrochloric acid solution and acetic acid solution.

[0019] Further, the organic solvent is selected from at least one of cyclohexane, cyclohexanol, and pentanol.

[0020] Further, the organosilicon source is selected from at least one of tetrabutyl orthosilicate, tetraisopropyl orthosilicate, tetraethyl orthosilicate, and tetramethyl orthosilicate.

[0021] Further, the mass ratio of the organosilicon source to the surfactant is 7 - 9:1.

[0022] Further, the mass ratio of the organic solvent to water is 1:1 - 2.

[0023] Further, the temperature of the crystallization reaction is 100 - 150 °C, and the time of the crystallization reaction is 4 - 8 h.

[0024] Further, the temperature of the second calcination is 450 - 550 °C, and the time of the second calcination is 5 - 6 h.

[0025] Further, in step S2, the organic alcohol is selected from at least one of methanol and ethanol.

[0026] Further, the mass ratio of the silica support to the organic alcohol is 1:30 - 40.

[0027] Further, the alkaline solution is selected from at least one of ammonia water solution and sodium hydroxide solution.

[0028] Further, the V source is selected from at least one of ammonium metavanadate and sodium metavanadate.

[0029] Further, the M source includes at least one of Mo source, Ce source, and Ti source; wherein, the Mo source is selected from at least one of sodium molybdate and ammonium molybdate; the Ce source is selected from at least one of cerium chloride and cerium nitrate; the Ti source is selected from at least one of tetrabutyl titanate and tetraisopropyl titanate.

[0030] Further, the temperature of the first calcination is 350 - 450 °C, and the time of the first calcination is 3 - 4 h. According to the third aspect of the present application, there is also provided a synthesis method of pyroxasulfone, which includes: an oxidation reaction of the thioether intermediate of formula (A) with hydrogen peroxide under the action of a catalyst to obtain pyroxasulfone. The synthesis schematic diagram of pyroxasulfone is as follows:

[0031]

[0032] Among them, the catalyst is the catalyst provided in the first aspect above or the catalyst obtained according to the preparation method provided in the second aspect.

[0033] Furthermore, the catalyst is loaded in a fixed bed, and the temperature of the oxidation reaction is 60 - 65 °C.

[0034] Applying the technical solution of the present application, the catalyst for synthesizing oxasulfuron provided by the present application uses silica with a large specific surface area, a large pore volume, and a three-dimensional dendritic pore structure inside as the carrier, and introduces the main active component V and the auxiliary active component M to cooperate with each other, so that the metal V and M form V - O - Si and M - O - Si bonds with the carrier, thereby easily forming nanoscale microcrystals embedded on the surface of silica. Moreover, the lattice oxygen in this bridging oxygen atom can improve the activity of the catalyst, which is more conducive to the oxidation of the thioether group to sulfone.

[0035] The catalyst provided by the present application is used in the synthesis of oxasulfuron, with the raw material conversion rate reaching 100% and the product purity ≥ 90%. It effectively reduces the preparation cost and post-treatment difficulty of oxasulfuron, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The specification drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0037] Figure 1 Shows the XRD pattern of the silica carrier prepared in Example 1 of the present application;

[0038] Figure 2 Shows the SEM image of the silica carrier prepared in Example 1 of the present application;

[0039] Figure 3 Shows the TEM image of the silica carrier prepared in Example 1 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will describe the present application in detail with reference to the embodiments.

[0041] As analyzed in the background art of the present application, the main catalysts for oxidizing existing thioether intermediates to prepare pyroxasulfone are sodium tungstate, tungsten oxide, ammonium molybdate, inorganic acids, ionic liquids, etc. However, in the homogeneous reaction system using sodium tungstate as the catalyst, the heat release of the reaction is large and the process risk is high; in the batch process using sodium tungstate and ammonium molybdate as the catalysts, limited by the heat transfer and mass transfer of the batch equipment itself, the reaction time is long and the reaction effect is poor; using inorganic acids or ionic liquids as the catalysts has high costs and cannot be recycled, resulting in high post-treatment costs. To solve at least one of the foregoing problems, the present application provides a catalyst for synthesizing pyroxasulfone, a preparation method thereof, and a synthesis method of pyroxasulfone.

[0042] In the first typical embodiment of the present application, a catalyst for synthesizing pyroxasulfone is provided, which includes a silica support having three-dimensional dendritic pores inside, and the silica support is loaded with a main active component V and a co-active component M, wherein M includes at least one of Mo, Ce, and Ti; and the specific surface area of the catalyst is 650-750 m 2 / g, the total pore volume is 0.8-1.3 cm 3 / g, and the average pore diameter is 5-10 nm.

[0043] The catalyst for synthesizing pyroxasulfone provided by the present application uses silica with a large specific surface area, a large pore volume, and three-dimensional dendritic pores inside as the support, and introduces the main active component V and the co-active component M to cooperate with each other, so that the metal V and M form V-O-Si and M-O-Si bonds with the support, thereby easily forming nanoscale microcrystals embedded on the surface of the silica, and the lattice oxygen in this bridging oxygen atom can improve the activity of the catalyst, which is more conducive to the oxidation of the thioether group to sulfone.

[0044] When the catalyst provided by the present application is used in the reaction for synthesizing pyroxasulfone, the raw material conversion rate reaches 100%, and the product purity ≥ 90%, effectively reducing the preparation cost and post-treatment difficulty of pyroxasulfone, and having broad application prospects.

[0045] Typically but not restrictively, the specific surface area of the catalyst for synthesizing pyroxasulfone provided by the present application can be 650 m 2 / g, 660 m 2 / g, 680 m 2 / g, 690 m 2 / g, 696.5 m 2 / g, 700 m 2 / g, 701.6 m 2 / g, 715 m 2 / g, 718m 2 / g, 718.96 m 2 / g, 719.04 m2 / g, 720 m 2 / g, 750 m 2 / g or a range value composed of any two of these values; if the total pore volume is 0.8 cm 3 / g, 0.84 cm 3 / g, 0.88 cm 3 / g, 0.90 cm 3 / g, 0.91 cm 3 / g, 0.916 cm 3 / g, 0.93 cm 3 / g, 0.95 cm 3 / g, 0.98 cm 3 / g, 0.99 cm 3 / g, 1.0 cm 3 / g, 1.036 cm 3 / g, 1.10 cm 3 / g, 1.15 cm 3 / g, 1.20 cm 3 / g, 1.221 cm 3 / g, 1.25 cm 3 / g, 1.30 cm 3 / g, or a range value composed of any two of these values; if the average pore diameter is 5.0 nm, 5.5 nm, 6.0 nm, 6.5 nm, 7.0 nm, 7.5 nm, 8.0 nm, 8.5 nm, 9.0 nm, 9.5 nm, 10 nm or a range value composed of any two of these values.

[0046] In some embodiments, M is Ce. In the catalyst, the molar ratio of Si, V, and Ce is 1: (0.2 - 0.3): (0.02 - 0.03).

[0047] In some embodiments, M is Mo. In the catalyst, the molar ratio of Si, V, and Mo is 1: (0.2 - 0.3): (0.01 - 0.02).

[0048] In some embodiments, M is Ti. In the catalyst, the molar ratio of Si, V, and Ti is 1: (0.2 - 0.3): (0.01 - 0.03).

[0049] In some embodiments, M includes Mo and Ti. In the catalyst, the molar ratio of Si, V, Mo, and Ti is 1: (0.2 - 0.3): (0.01 - 0.02): (0.01 - 0.03).

[0050] In some embodiments, M includes Ce, Mo, and Ti. In the catalyst for synthesizing oxasulfuron provided in the present application, the molar ratio of Si, V, Ce, Mo, and Ti is 1:(0.2 - 0.3):(0.02 - 0.03):(0.01 - 0.02):(0.01 - 0.03).

[0051] In the catalyst for synthesizing oxasulfuron provided in the present application, based on the molar amount of Si in the catalyst being 1.0, the molar amount of V can be 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30 or a range value composed of any two numerical values; the molar amount of Ti can be 0.01, 0.012, 0.015, 0.018, 0.02, 0.022, 0.025, 0.028, 0.03 or a range value composed of any two numerical values; the molar amount of Mo can be 0.01, 0.012, 0.015, 0.018, 0.02 or a range value composed of any two numerical values; the molar amount of Ce can be 0.02, 0.022, 0.025, 0.028, 0.03 or a range value composed of any two numerical values.

[0052] To facilitate loading the catalyst provided in the present application into a fixed bed for continuous synthesis of oxasulfuron, in some embodiments, the catalyst for synthesizing oxasulfuron provided in the present application is granular, with a particle size of 10 - 20 mesh, such as 10 mesh, 12 mesh, 15 mesh, 18 mesh, 20 mesh or a range value composed of any two numerical values.

[0053] In the second typical embodiment of the present application, a preparation method of the catalyst for oxasulfuron provided in the above first typical embodiment is provided. The preparation method includes the following steps: Step S1, preparing a silica support with three-dimensional dendritic pores; Step S2, dispersing the silica support in an organic alcohol solvent and adding an alkaline solution to adjust the pH to obtain a silica suspension with a pH of 10 - 11; Step S3, adding a V source and an M source to the silica suspension so that V and M are loaded on the silica support, and removing the solvent to obtain a catalyst precursor; Step S4, performing a first calcination on the catalyst precursor to obtain the catalyst.

[0054] The preparation method of the catalyst for oxasulfuron provided in the present application has a simple process, is easy to operate, is conducive to large-scale production, and thus reduces production costs.

[0055] In the above step S2, the pH of the silica suspension can be 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11 or a range value composed of any two numerical values.

[0056] In some embodiments, the above-mentioned step S1 includes: step S11, dispersing a templating agent, a surfactant, and an acidic solution in water to obtain solution A with a pH of 0.5 - 1; step S12, sequentially adding an organic solvent and a silicon source in solution A to obtain solution B; step S13, transferring solution B to a reaction kettle for crystallization reaction to obtain a silica support precursor; step S14, subjecting the silica support precursor to a second calcination to obtain a silica support.

[0057] The pH of the above-mentioned solution A can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or a range value composed of any two numerical values.

[0058] The above-mentioned templating agent is a commonly used templating agent in the art, including but not limited to any one or more of ammonium D,L-tartrate, pyrrolidone, cyclohexylamine, and piperidine. Preferably, ammonium D,L-tartrate is more conducive to improving the preparation efficiency.

[0059] The above-mentioned surfactant is a commonly used surfactant in the art, including but not limited to any one or more of cetyltrimethylammonium bromide, cetylpyridinium bromide, and Tween 80.

[0060] The above-mentioned acidic solution is an acidic solution commonly used in the art to adjust the pH value, including but not limited to a mixed solution of one or two of hydrochloric acid solution or acetic acid solution. Preferably, hydrochloric acid solution is more conducive to avoiding the introduction of impurity ions. Further preferably, it is a hydrochloric acid solution with a mass concentration of 35 - 40%.

[0061] The above-mentioned organic solvent is a commonly used organic solvent in the art, including but not limited to any one or a mixed solution of two or more solvents of cyclohexane, cyclohexanol, or pentanol.

[0062] The above-mentioned silicon source is a silicon source commonly used in the art to prepare silica, including but not limited to any one or more of tetrabutyl orthosilicate, tetraisopropyl orthosilicate, tetraethyl orthosilicate, and tetramethyl orthosilicate. Preferably, it is tetraisopropyl orthosilicate or tetraethyl orthosilicate.

[0063] In order to further prepare a silica support with a large pore volume, a large specific surface area, and uniform pore diameters, in some embodiments, the mass ratio of the silicon source to the surfactant is 7 - 9:1, such as 7.2:1, 7.4:1, 7.6:1, 7.8:1, 8:1, 8.2:1, 8.4:1, 8.6:1, 8.8:1, 9:1 or a range value composed of any two numerical values. In some embodiments, the mass ratio of the organic solvent to water is 1:1 - 2 (such as 1:1, 1:1.1, 1:1.2, 1:1.5, 1:1.8, 1:2.0). Further preferably, it is 1:1.

[0064] To further improve the efficiency of the crystallization reaction, the temperature of the crystallization reaction is preferably 100 - 150 °C, and the time of the crystallization reaction is 4 - 8 h. The temperature of the crystallization reaction can be 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C or a range value composed of any two values; the time of the crystallization reaction can be 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h or a range value composed of any two values.

[0065] In the above step S13, after the crystallization reaction is completed to obtain a crystallization product mixture, the crystallization product mixture is subjected to solid-liquid separation and then washed and dried in deionized water to obtain a silica carrier precursor. The aforementioned solid-liquid separation method is preferably filtration.

[0066] To further improve the preparation efficiency of the silica carrier, the temperature of the second calcination is preferably 450 - 550 °C, and the time of the second calcination is 5 - 6 h. The temperature of the second calcination can be 450 °C, 480 °C, 500 °C, 520 °C, 550 °C or a range value composed of any two values; the time of the second calcination can be 5 h, 5.2 h, 5.5 h, 5.8 h, 6 h or a range value composed of any two values.

[0067] In some embodiments, the heating rate of the silica precursor to the temperature of the second calcination is 5 - 15 °C / min (such as 5 °C / min, 8 °C / min, 10 °C / min, 12 °C / min, 15 °C / min), which is beneficial to make the pores and pore volume of the silica carrier more uniform.

[0068] In the above step S2, the organic alcohol solution is used to disperse the silica carrier. From the perspectives of environmental protection and dispersion efficiency, it is preferred that the organic alcohol is selected from any one or a mixture of methanol and ethanol.

[0069] To further improve the preparation efficiency of the silica suspension, the mass ratio of the silica carrier to the organic alcohol is preferably 1:30 - 40, such as 1:30, 1:32, 1:35, 1:38, 1:40 or a range value composed of any two values.

[0070] The above alkaline solution is used to adjust the pH of the silica suspension to 10 - 11. Any common alkaline solution in the art can be used, including but not limited to at least one of ammonia water solution or sodium hydroxide solution. To further reduce the introduction of impurities, it is preferred that the alkaline solution is ammonia water solution, and more preferably ammonia water solution with a mass concentration of 20 - 30%.

[0071] In some embodiments, the ammonia water solution is added dropwise to the organic alcohol solution of the silica carrier, and the time for adding the ammonia water solution is controlled within 3 - 5 min.

[0072] In the above step S3, the above V source is a commonly used V salt in the art, including but not limited to any one or a mixture of more than one of ammonium metavanadate or sodium metavanadate.

[0073] The above M source includes any one or more of a Mo source, a Ce source, and a Ti source; among them, the Mo source includes but not limited to any one or more of sodium molybdate or ammonium molybdate; the Ce source is selected from any one or more of cerium chloride or cerium nitrate; the Ti source includes but not limited to any one or more of tetrabutyl titanate or tetraisopropyl titanate.

[0074] In the above step S3, the method of removing the solvent includes but not limited to heating, so as to remove solvents and impurities such as water or ammonia introduced by the organic alcohol and the alkaline solution. In some embodiments, it is heated to 75 - 85 °C to facilitate the removal of the solvent and impurities.

[0075] In order to further improve the preparation efficiency of the catalyst, it is preferred that the temperature of the first calcination is 350 - 450 °C and the time of the first calcination is 3 - 4 h. Specifically, the temperature of the first calcination is, for example, 350 °C, 380 °C, 400 °C, 420 °C, 450 °C or a range value composed of any two numerical values; the time of the first calcination is, for example, 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h or a range value composed of any two numerical values.

[0076] In some embodiments, it is preferred to perform step S4. First, the catalyst precursor is dried and then subjected to the first calcination.

[0077] Specifically, the catalyst precursor is first dried at 80 - 100 °C for 6 - 8 h, and then heated to the first calcination temperature at a rate of 5 °C - 15 °C / min for calcination.

[0078] In some embodiments, in order to facilitate loading the above catalyst into a fixed bed for the continuous synthesis of oxasulfuron, the above step S4 further includes successively performing tabletting and crushing on the catalyst, so as to obtain a catalyst with an average particle size of 10 - 20 mesh.

[0079] In the third typical embodiment of the present application, a method for synthesizing oxasulfuron is further provided. The synthesis method includes: subjecting a thioether intermediate and hydrogen peroxide to an oxidation reaction under the action of a catalyst to obtain oxasulfuron, wherein the schematic diagram of the synthesis of this oxasulfuron is as follows:

[0080]

[0081] Among them, the above catalyst is the catalyst provided by the above first typical embodiment or the catalyst obtained according to the preparation method provided by the above second typical embodiment.

[0082] The synthesis method of pyroxasulfone provided by this application involves loading the above catalyst in a fixed bed, and then sulfur ether intermediates and hydrogen peroxide can be introduced into the fixed bed respectively. Under the catalytic action of the catalyst, the sulfur ether intermediates and hydrogen peroxide react to produce pyroxasulfone. Not only can the raw material conversion rate reach 100%, but also the product purity is ≥90%. The continuous synthesis of pyroxasulfone can be achieved, which is more conducive to reducing production costs.

[0083] In addition, this application uses silica with three-dimensional dendritic pores inside as the carrier. Due to the abundant pores inside, the main active component and the auxiliary active component can be better dispersed on the surface of the pores of the silica, improving the metal dispersion of the main active component. The improvement of dispersion greatly enhances its atomic utilization rate, reduces the input amount of the active component, and thus reduces the cost of catalyst preparation. The catalyst provided by this application can be directly applied to a continuous fixed bed, eliminating the adverse effects of factors such as heat transfer, mass transfer, and long reaction time, and significantly improving the safety and productivity of the process.

[0084] In some embodiments, the temperature of the above oxidation reaction is 60 - 65 °C. The reaction is mild, which is more conducive to process control. Moreover, the catalyst is loaded in the fixed bed and can be used continuously.

[0085] In some specific embodiments, when using a fixed bed for the continuous preparation of pyroxasulfone, an acetonitrile solution of sulfur ether intermediates with a flow rate of 0.5 g / min (the mass ratio of acetonitrile to sulfur ether intermediates is 3:1) is introduced into the fixed bed, and an aqueous hydrogen peroxide solution with a flow rate of 0.1 g / min (mass concentration 50%) is introduced into the fixed bed, and an overflow reaction form is adopted.

[0086] The beneficial effects of this application will be further illustrated below in combination with examples and comparative examples.

[0087] Example 1

[0088] This example provides a catalyst, which includes a silica carrier with three-dimensional dendritic pores inside. The silica carrier is loaded with the main active component V and the auxiliary active component Ce, and the molar ratio of Si, V, and Ce is 1:0.2:0.02.

[0089] This catalyst is prepared according to the following steps:

[0090] (1) Preparation of a silica carrier with three-dimensional dendritic pores

[0091] (1.1) Weigh 25 g of ammonium D,L-tartrate, 25 g of cetyltrimethylammonium bromide CTAB, and 125 g of hydrochloric acid, dissolve them in 1400 mL of deionized water, and stir at room temperature until completely dissolved to obtain solution A with a pH of 0.7;

[0092] (1.2) Add 1330 mL of cyclohexane and 70 mL of pentanol to the above solution A, stir vigorously at room temperature for 30 minutes, slowly add 200 g of tetraethyl orthosilicate, and then continue to stir at room temperature for 25 - 30 minutes to obtain solution B;

[0093] (1.3) Transfer solution B to a sealed polytetrafluoroethylene autoclave, heat at 120 °C for 5 hours for crystallization reaction. After the crystallization reaction is completed, filter and separate, wash the crystallization product with deionized water, and dry in an oven at a drying temperature of 80 °C for 5 h to obtain a silica support precursor;

[0094] (1.4) Calcinate the silica support precursor in air at 550 °C at a heating rate of 5 °C / min for 5 hours, and obtain a white silica support after grinding.

[0095] (2) Put 40 g of the silica support into a round-bottom flask containing 1200 g of ethanol, disperse the silica support suspension by ultrasonic treatment for 15 - 20 minutes, then stir at room temperature for 5 - 10 minutes. In the stirred solution, add 25 wt% ammonia water (within 3 minutes) to obtain a silica suspension with a pH of 11.

[0096] (3) Then add 15.6 g of ammonium metavanadate, 4.35 g of cerium nitrate and 5 mL of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 80 °C to evaporate ethanol and ammonia to obtain a catalyst precursor.

[0097] (4) After drying the catalyst precursor at 100 °C for 8 h, put the solid product into a muffle furnace at 400 °C and calcine for 4 hours, with a heating rate of 5 °C / min, to obtain a bulk catalyst. After simply pressing the bulk catalyst with a tablet press, crush it to 10 - 20 mesh to obtain the aforementioned catalyst.

[0098] Example 2

[0099] This example provides a catalyst, which includes a silica support with three-dimensional dendritic pores inside. The silica support is loaded with a main active component V and a co-active component Mo, and the molar ratio of Si, V and Mo is 1:0.3:0.015.

[0100] This catalyst is prepared according to the following steps:

[0101] (1) Prepare a silica support with three-dimensional dendritic pores

[0102] (1.1) Weigh 20 g of ammonium D,L-tartrate, 30 g of Tween 80 and 120 g of hydrochloric acid, dissolve them in 1200 mL of deionized water, and stir at room temperature until completely dissolved to obtain solution A with a pH of 0.5;

[0103] (1.2) Add 1330 mL of cyclohexane and 70 mL of pentanol to the above solution A, stir vigorously at room temperature for 30 minutes, slowly add 250 g of tetra-isopropyl orthosilicate, and then continue to stir at room temperature for 25 - 30 minutes to obtain solution B;

[0104] (1.3) Transfer solution B to a sealed polytetrafluoroethylene autoclave, heat at 150 °C for 4 hours for crystallization reaction. After the crystallization reaction is completed, filter and separate, wash the crystallization product with deionized water, dry in an oven at a drying temperature of 90 °C for 4 h to obtain a silica support precursor;

[0105] (1.4) Calcinate the silica support precursor in air at 550 °C at a heating rate of 15 °C / min for 5 hours, and grind to obtain a white silica support.

[0106] (2) Put 40 g of the silica support into a round-bottom flask containing 1600 g of ethanol, disperse the silica support suspension by ultrasonic treatment for 15 - 20 minutes, then stir at room temperature for 5 - 10 minutes. In the stirred solution, add 25 wt% ammonia water (within 5 minutes) to obtain a silica suspension with a pH reaching 10.

[0107] (3) Then add 23.4 g of ammonium metavanadate, 1.96 g of ammonium molybdate and 10 mL of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 80 °C to evaporate ethanol and ammonia to obtain a catalyst precursor.

[0108] (4) After drying the catalyst precursor at 80 °C for 8 h, put the solid product into a muffle furnace at 450 °C and calcine for 3 hours, with a heating rate of 10 °C / min, to obtain a bulk catalyst. After simply pressing the bulk catalyst with a tablet press, crush it to 10 - 20 mesh to obtain the aforementioned catalyst.

[0109] Example 3

[0110] This example provides a catalyst, which includes a silica support with three-dimensional dendritic pores inside. The silica support is loaded with a main active component V and co-active components Mo and Ti, and the molar ratio of Si, V, Mo, and Ti is 1:0.2:0.015:0.02.

[0111] This catalyst is prepared according to the following steps:

[0112] (1) Preparation of a silica support with three-dimensional dendritic pores

[0113] (1.1) Weigh 30 g of ammonium D,L-tartrate, 25 g of cetylpyridinium bromide (CPB), and 110 g of hydrochloric acid, dissolve them in 1150 mL of deionized water, and stir at room temperature until completely dissolved to obtain solution A with a pH of 1;

[0114] (1.2) Add 1050 mL of cyclohexane, 30 mL of pentanol, and 70 mL of cyclohexanol to the above solution A, stir vigorously at room temperature for 30 minutes, slowly add 220 g of tetra-isopropyl orthosilicate, and then continue to stir at room temperature for 25 - 30 minutes to obtain solution B;

[0115] (1.3) Transfer solution B to a sealed polytetrafluoroethylene autoclave, heat at 120 °C for 6 hours for the crystallization reaction. After the crystallization reaction is completed, filter and separate, wash the crystallization product with deionized water, and dry in an oven at a drying temperature of 85 °C for 5 h to obtain a silica support precursor;

[0116] (1.4) Calcinate the silica support precursor in air at 500 °C at a heating rate of 12 °C / min for 6 hours, and grind to obtain a white silica support.

[0117] (2) Place 40 g of the silica support into a round-bottom flask containing 1500 g of ethanol, disperse the silica support suspension by ultrasonic treatment for 15 - 20 minutes, then stir at room temperature for 5 - 10 minutes. In the stirred solution, add 25 wt% ammonia water (within 3 minutes) to obtain a silica suspension with a pH reaching 11.

[0118] (3) Then, add 15.6 g of ammonium metavanadate, 1.96 g of ammonium molybdate, 4.54 g of tetrabutyl titanate, and 10 mL of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 85 °C to evaporate ethanol and ammonia to obtain a catalyst precursor.

[0119] (4) After drying the catalyst precursor at 80 °C for 7 h, place the solid product in a muffle furnace at 450 °C for 3 hours, with a heating rate of 10 °C / min, to obtain a bulk catalyst. After simply pressing the bulk catalyst with a tablet press, crush it to 10 - 20 mesh to obtain the aforementioned catalyst.

[0120] Example 4

[0121] This embodiment provides a catalyst, which includes a silica support with three-dimensional dendritic pores inside. The silica support is loaded with a main active component V and auxiliary active components Ce, Mo, and Ti, and the molar ratio of Si, V, Ce, Mo, and Ti is 1:0.27:0.01:0.01:0.01.

[0122] This catalyst is prepared according to the following steps:

[0123] (1) Prepare a silica support with three-dimensional dendritic pores

[0124] (1.1) Weigh 30 g of ammonium D,L-tartrate, 30 g of cetylpyridinium bromide CPB, and 130 g of hydrochloric acid, dissolve them in 1400 mL of deionized water, and stir at room temperature until completely dissolved to obtain solution A with a pH of 0.6;

[0125] (1.2) Add 1300 mL of cyclohexane and 100 mL of cyclohexanol to the above solution A, vigorously stir at room temperature for 30 minutes, slowly dropwise add 220 g of tetraethyl orthosilicate, and then continue to stir at room temperature for 25 - 30 minutes to obtain solution B;

[0126] (1.3) Transfer solution B to a sealed polytetrafluoroethylene autoclave, heat at 120 °C for 6 hours for the crystallization reaction. After the crystallization reaction is completed, filter and separate, wash the crystallization product with deionized water, and dry it in an oven at a drying temperature of 85 °C for 5 h to obtain a silica support precursor;

[0127] (1.4) Calcinate the silica support precursor in air at 500 °C at a heating rate of 12 °C / min for 6 hours, and grind it to obtain a white silica support.

[0128] (2) Put 40 g of the silica support into a round-bottom flask containing 1400 g of methanol, disperse the silica support suspension by ultrasonic treatment for 15 - 20 minutes, then stir at room temperature for 5 - 10 minutes. In the stirred solution, dropwise add 25 wt% ammonia water (for 3 minutes) to obtain a silica suspension with a pH reaching 11.

[0129] (3) Then, add 22 g of sodium metavanadate, 1.64 g of cerium chloride, 1.5 g of sodium molybdate, 1.89 g of tetra-isopropyl titanate, and 10 mL of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 85 °C to evaporate ethanol and ammonia to obtain a catalyst precursor.

[0130] After drying the catalyst precursor at 80 °C for 7 h, the solid product was calcined in a muffle furnace at 450 °C for 3 h with a heating rate of 10 °C / min to obtain a massive catalyst. The massive catalyst was simply pressed by a tablet press and then crushed to 10-20 mesh to obtain the aforementioned catalyst.

[0131] Example 5

[0132] The difference between this example and Example 1 is that in step (1.3), the amount of cetyltrimethylammonium bromide used is 23 g, and the crystallization reaction temperature is 110 °C, and the crystallization reaction time is 4 h.

[0133] Example 6

[0134] The difference between this example and Example 1 is that in step (1.3), the amount of cetyltrimethylammonium bromide used is 25 g, and the crystallization reaction temperature is 150 °C, and the crystallization reaction time is 8 h.

[0135] Example 7

[0136] The difference between this example and Example 1 is that in step (3), the amount of ammonium metavanadate used is 15.6 g, and the amount of cerium nitrate used is 6.52 g.

[0137] Example 8

[0138] The difference between this example and Example 1 is that in step (3), the amount of ammonium metavanadate used is 23.4 g, and the amount of cerium nitrate used is 4.35 g.

[0139] Example 9

[0140] The difference between this example and Example 2 is that in step (3), the amount of ammonium metavanadate used is 23.4 g, and the amount of ammonium molybdate used is 1.3 g.

[0141] Example 10

[0142] The difference between this example and Example 2 is that in step (3), the amount of ammonium metavanadate used is 15.6 g, and the amount of ammonium molybdate used is 2.6 g.

[0143] Example 11

[0144] The difference between this example and Example 2 is that in step (3), the amount of ammonium metavanadate used is 15.6 g, the amount of ammonium molybdate used is 2.6 g, and the amount of tetrabutyl titanate used is 2.3 g.

[0145] Example 12

[0146] The difference between this example and Example 2 is that in step (3), the amount of ammonium metavanadate is 23.4 g, the amount of ammonium molybdate is 1.3 g, and the amount of tetrabutyl titanate is 6.8 g.

[0147] Example 13

[0148] The difference between this example and Example 3 is that in step (3), the amount of ammonium metavanadate is 23.4 g, and the amount of tetrabutyl is 2.3 g.

[0149] Example 14

[0150] The difference between this example and Example 3 is that in step (3), the amount of ammonium metavanadate is 15.6 g, and the amount of tetrabutyl titanate is 6.8 g.

[0151] Example 15

[0152] The difference between this example and Example 4 is that in step (3), the amount of sodium metavanadate is 16.3 g, the amount of cerium chloride is 4.9 g, the amount of sodium molybdate is 1.4 g, and the amount of tetraisopropyl titanate is 5.7 g.

[0153] Example 16

[0154] The difference between this example and Example 4 is that in step (3), the amount of ammonium metavanadate is 23.4 g, the amount of cerium chloride is 3.3 g, the amount of sodium molybdate is 2.7 g, and the amount of tetraisopropyl titanate is 1.9 g.

[0155] Example 17

[0156] The difference between this example and Example 1 is that in step (3), the amount of cerium chloride is 2.5 g.

[0157] Example 18

[0158] The difference between this example and Example 1 is that in step (3), the amount of cerium chloride is 6.6 g.

[0159] Example 19

[0160] The difference between this example and Example 2 is that in step (3), the amount of ammonium molybdate is 0.65 g.

[0161] Example 20

[0162] The difference between this example and Example 2 is that in step (3), the amount of ammonium molybdate is 3.9 g.

[0163] Example 21

[0164] The difference between this example and Example 3 is that in step (3), the amount of ammonium metavanadate is 15.6 g, and the amount of tetrabutyl titanate is 1.1 g.

[0165] Example 22

[0166] The difference between this example and Example 4 is that in step (3), the amount of sodium metavanadate is 22 g, and the amount of tetrabutyl titanate is 0.9 g.

[0167] Comparative Example 1

[0168] This comparative example provides a catalyst, which includes a silica carrier and active components V, co-active components Ce, Mo and Ti supported on the silica carrier, and the molar ratio of Si, V, Ce, Mo and Ti is 1: 0.27:0.01:0.01:0.01.

[0169] It is prepared according to the following steps:

[0170] (1) Put 40 g of commercial silica carrier (purchased from Innochem, model A26027) into a round-bottom flask containing 1400 g of methanol. After 15 - 20 minutes of ultrasonic treatment to disperse the silica carrier suspension, then stir at room temperature for 5 - 10 minutes. In the stirred solution, add 25 wt% ammonia water (for 3 minutes) to obtain a silica suspension with a pH reaching 11.

[0171] (2) Then, add 22 g of sodium metavanadate, 1.64 g of cerium chloride, 1.5 g of sodium molybdate, 1.89 g of tetra-isopropyl titanate and 10 ml of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 85 °C to evaporate ethanol and ammonia to obtain a catalyst precursor.

[0172] (3) After drying the catalyst precursor at 80 °C for 7 h, put the solid product into a muffle furnace at 450 °C and calcine for 3 h, with a heating rate of 10 °C / min to obtain a block catalyst. After simply pressing the block catalyst with a tablet press, crush it to 10 - 20 mesh to obtain the aforementioned catalyst.

[0173] Comparative Example 2

[0174] This comparative example provides a catalyst, which includes a silica carrier and active components V, co-active components Ce, Mo and Ti supported on the silica carrier, and the molar ratio of Si, V, Ce, Mo and Ti is 1:0.3:0:0.015:0.

[0175] It is prepared according to the following steps:

[0176] (1) Put 40 g of commercial silica support (purchased from Innochem, model A26027) into a round-bottom flask containing 1600 g of methanol. After 15 - 20 minutes of ultrasonic treatment to disperse the silica support suspension, stir for 5 - 10 minutes at room temperature. In the stirred solution, add 25 wt% ammonia water (for 5 minutes) to obtain a silica suspension with a pH of 10.

[0177] (2) Then, add 23.4 g of sodium metavanadate, 1.96 g of ammonium molybdate, and 10 mL of deionized water to the silica suspension under stirring at room temperature to obtain a mixed solution. Heat the mixed solution to 80 °C to evaporate methanol and ammonia, obtaining a catalyst precursor.

[0178] (3) After drying the catalyst precursor at 80 °C for 7 h, put the solid product into a muffle furnace at 450 °C and calcine for 3 h with a heating rate of 10 °C / min to obtain a bulk catalyst. After simply pressing the bulk catalyst with a tablet press, crush it to 10 - 20 mesh to obtain the aforementioned catalyst.

[0179] Test Example 1

[0180] Perform XRD test on the silica support obtained in step (1.4) of Example 1. The results are as Figure 1 shown. It can be seen from Figure 1 that the synthesized support is mesoporous silica and has orderliness (the pore diameter can be calculated as mesoporous by using Bragg's formula in combination with the peak angles of the XRD pattern).

[0181] Perform SEM and TEM tests on the catalyst provided in Example 1 above. The results are as Figure 2 and Figure 3 shown. It can be seen from Figure 2 and Figure 3 that the catalyst is spherical, and there are wrinkles and pores on the surface of the spherical catalyst, indicating that the carbon dioxide support has a three-dimensional dendritic pore structure inside.

[0182] Test Example 2

[0183] Measure the specific surface area, total pore volume, and average pore diameter of the catalysts provided in the above examples and comparative examples. The results are shown in Table 1 below.

[0184] Fill 40 g of the catalysts provided in the above examples and comparative examples into a fixed bed respectively. For the thioether intermediate ( The acetonitrile solution of ( ) (the mass ratio of acetonitrile to the thioether intermediate is 3:1) was introduced into the fixed bed at a rate of 0.5 g / min, and at the same time, the hydrogen peroxide solution (mass concentration of 50%) was introduced into the fixed bed at a rate of 0.1 g / min for continuous oxidation at 60 °C, and the oxadiargyl reaction solution was obtained by an overflow reaction form. The conversion rate of the thioether intermediate and the selectivity of oxadiargyl were measured, and the results are shown in Table 1.

[0185] Among them, (1) the specific surface area, total pore volume and average pore diameter of the catalyst were measured using the BSD-660SA3S equipment of Beijing Beishide Instrument Co., Ltd.

[0186] (2) The measurement method for the conversion rate of the thioether intermediate is: conversion rate (%) = (1 - the number of moles of the thioether intermediate in the oxadiargyl reaction solution / the number of moles of the thioether intermediate input) * 100% (3) The purity of oxadiargyl was measured using a high performance liquid chromatograph.

[0187] Table 1

[0188]

[0189] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects: By applying the technical solution of the present application, the catalyst for synthesizing oxadiargyl provided by the present application uses silica with a large specific surface area, a large pore volume and a three-dimensional dendritic pore structure inside as the carrier, and the main active component V and the auxiliary active component M are introduced and cooperate with each other, so that the metal V and M form V-O-Si and M-O-Si bonds with the carrier, thus easily forming nanoscale microcrystals embedded on the surface of silica, and the lattice oxygen in this bridging oxygen atom can improve the activity of the catalyst, which is more conducive to the oxidation of the thioether group to sulfone.

[0190] The catalyst provided by the present application is used in the synthesis of oxadiargyl, the raw material conversion rate reaches 100%, the product purity ≥ 90%, effectively reducing the preparation cost and post-treatment difficulty of oxadiargyl, and having broad application prospects.

[0191] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A catalyst for synthesizing sulfonepyraclostrobin, characterized in that: The catalyst comprises a silica carrier having three-dimensional dendritic channels inside, the silica carrier is loaded with a main active component V and an auxiliary active component M, wherein M comprises at least one of Mo, Ce and Ti; and the specific surface area of ​​the catalyst is 650-750m 2 / g, total pore volume is 0.8-1.3m 3 / g, average pore size is 5-10nm; When the M is Ce, the molar ratio of Si, V, and Ce in the catalyst is 1: (0.2-0.3): (0.02-0.03); When the M is Mo, the molar ratio of Si, V and Mo in the catalyst is 1: (0.2-0.3): (0.01-0.02); When the M is Ti, the molar ratio of Si, V and Ti in the catalyst is 1: (0.2-0.3): (0.01-0.03); When the M includes Mo and Ti, the molar ratio of Si, V, Mo and Ti in the catalyst is 1: (0.2-0.3): (0.01-0.02): (0.01-0.03); When the M includes Ce, Mo and Ti, the molar ratio of Si, V, Ce, Mo and Ti in the catalyst is 1: (0.2-0.3): (0.02-0.03): (0.01-0.02): (0.01-0.03); The preparation method of the silica carrier having three-dimensional dendritic channels comprises: Step S11, dispersing the template, surfactant and acidic solution in water to obtain a solution A with a pH of 0.5-1; Step S12, adding an organic solvent and an organosilicon source to solution A in sequence to obtain solution B; Step S13, transferring solution B to a reactor for crystallization reaction to obtain a silica carrier precursor; Step S14, performing a second calcination on the silica carrier precursor to obtain the silica carrier.

2. The catalyst according to claim 1, characterized in that The catalyst is in granular form, and its particle size is 10-20 meshes.

3. A method for preparing the catalyst according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: Step S1, preparing a silica carrier having three-dimensional dendritic channels; Step S2, dispersing the silica carrier in an organic alcohol and adding an alkaline solution to adjust the pH to obtain a silica suspension with a pH of 10-11; Step S3, adding a V source and an M source to the silica suspension so that V and M are loaded on the silica carrier, and removing the solvent to obtain a catalyst precursor; Step S4, performing a first calcination on the catalyst precursor to obtain the catalyst; Wherein, the step S1 comprises: Step S11, dispersing the template, surfactant and acidic solution in water to obtain a solution A with a pH of 0.5-1; Step S12, adding an organic solvent and an organic silicon source to solution A in sequence to obtain solution B; Step S13, transferring solution B to a reactor for crystallization reaction to obtain a silica carrier precursor; Step S14, performing a second calcination on the silica carrier precursor to obtain the silica carrier.

4. The method for preparing the catalyst according to claim 3, characterized in that: The template agent is selected from at least one of D,L-ammonium tartrate, pyrrolidone, cyclohexylamine, and piperidine; And / or, the surfactant is selected from at least one of cetyltrimethylammonium bromide, cetylpyridinium bromide and Tween 80; and / or, the mass ratio of the template to the surfactant is (2-3): (2-3); And / or, the acidic solution is selected from at least one of a hydrochloric acid solution and an acetic acid solution; And / or, the organic solvent is selected from at least one of cyclohexane, cyclohexanol and pentanol; And / or, the organic silicon source is selected from at least one of tetrabutyl orthosilicate, tetraisopropyl orthosilicate, tetraethyl orthosilicate and tetramethyl orthosilicate; And / or, the mass ratio of the organosilicon source to the surfactant is 7-9:1; And / or, the mass ratio of the organic solvent to the water is 1:1-2; And / or, the temperature of the crystallization reaction is 100-150° C., and the time of the crystallization reaction is 4-8 hours; And / or, the temperature of the second calcination is 450-550° C., and the time of the second calcination is 5-6 hours.

5. The method for preparing the catalyst according to claim 3, characterized in that: In step S2, the organic alcohol is selected from at least one of methanol and ethanol; And / or, the mass ratio of the silica carrier to the organic alcohol is 1:30-40; And / or, the alkaline solution is selected from at least one of an aqueous ammonia solution or a sodium hydroxide solution; And / or, the V source is selected from at least one of ammonium metavanadate or sodium metavanadate; And / or, the M source includes at least one of a Mo source, a Ce source or a Ti source; wherein the Mo source is selected from at least one of sodium molybdate or ammonium molybdate; the Ce source is selected from at least one of cerium chloride or cerium nitrate; the Ti source is selected from at least one of tetrabutyl titanate or tetraisopropyl titanate; And / or, the temperature of the first calcination is 350-450° C., and the time of the first calcination is 3-4 hours.

6. A method for synthesizing sulfonepyraclostrobin, characterized in that: The synthesis method comprises: an oxidation reaction of a sulfide intermediate of formula (A) and hydrogen peroxide under the action of a catalyst to obtain the sulfonepyraclostrobin. The synthesis schematic diagram of the sulfonepyraclostrobin is as follows: ； Wherein, the catalyst is the catalyst according to claim 1 or 2 or the catalyst obtained by the preparation method according to any one of claims 3 to 5.

7. The synthesis method according to claim 6, characterized in that The catalyst is loaded in a fixed bed, and the temperature of the oxidation reaction is 60-65°C.

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