Preparation method of pyroxasulfone

Abstract

The invention relates to the technical field of organic synthesis, in particular to a method for preparing pyroxasulfone with the IPC classification number of C07D413 / 12, and particularly relates to a method for preparing pyroxasulfone with ozone as an oxidizing agent. The preparation method provided by the invention comprises the following steps: at a certain temperature and pressure, taking ozone as an oxidizing agent, and carrying out oxidation reaction between a compound 1 and the oxidizing agent in the presence of a catalyst to obtain pyroxasulfone. According to the preparation method, ozone is used as an oxidizing agent, ozone can be automatically decomposed into oxygen at normal temperature and normal pressure, and the defect that a hydrogen peroxide solution needs to be treated when hydrogen peroxide is used as the oxidizing agent is avoided, so that the preparation method is environment-friendly, and the defect of harmful emission is overcome; the preparation method disclosed by the invention is high in product purity and yield, simple and easy to control in operation process, and beneficial to industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, in particular to IPC classification number C07D413 / 12, and specifically to a method for preparing sulfonepyraclostrobin using ozone as an oxidant. Background Art

[0002] Pyroxasulfone is an isoxazole herbicide developed by Kumihiko Chemical Co., Ltd. in Japan in 2002. It is mainly used as a pre-emergence blocking agent. It has excellent effects on grasses and broadleaf weeds. It is applicable to a wide range of crops, including wheat, corn, peanuts, rice, soybeans, cotton and other crops, and has good application prospects. The chemical name is 3-[5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)pyrazol-4-ylmethylsulfonyl]-4,5-dihydro-5,5-dimethyl-1,2-isoxazole, and the chemical structure is:

[0003]

[0004] Prior art CN117567452A discloses a method for preparing sulfonepyraclostrobin, which mainly comprises the following steps:

[0005] The product is reacted with a catalyst, sodium tungstate, and an oxidant, hydrogen peroxide, in an alcohol solvent and purified by recrystallization. The product, sulfonepyraclostrobin, has a high yield and purity, and is conducive to industrial-scale manufacturing.

[0006] However, the inventors found in the actual research and development process that the above preparation method uses hydrogen peroxide as an oxidant, but hydrogen peroxide is corrosive and is also a carcinogen announced by the World Health Organization. Special treatment is required before discharge. Although hydrogen peroxide can be decomposed into oxygen and water, if there is no catalyst, the decomposition rate is very slow. This causes the production process of sulfonepyraclostrobin, and the wastewater discharge is large, which seriously pollutes the environment. In addition, the mother solution of crystallization needs to be distilled before the solvent can be applied, and the operation is complicated, and the energy consumption is large, which is not conducive to industrialization. Summary of the invention

[0007] In view of the above technical problems, the purpose of the present invention is to provide a method for preparing sulfonepyraclostrobin, which has the advantages of mild reaction conditions, low production cost, less three waste emissions, and environmental friendliness.

[0008] The technical scheme of the present invention is as follows: at a temperature of 10 to 120° C. and a pressure of 0.2 to 1.5 MPa, with ozone as an oxidant and in the presence of a catalyst, compound 1, ozone and a solvent are added in a certain proportion to carry out an oxidation reaction; after the reaction is completed, the reaction solution is cooled for crystallization, filtered and dried to obtain a crystalline white solid sulfonepyraclostrobin product sulfonepyraclostrobin; the chemical reaction formula of sulfonepyraclostrobin is as follows:

[0009]

[0010] Preferably, the catalyst for the oxidation reaction includes one or more combinations of manganese dioxide, chromium trioxide, vanadium pentoxide, titanium dioxide, ferric chloride, ammonium molybdate, sodium tungstate, and sodium periodate.

[0011] More preferably, it is ammonium molybdate (CAS: 12054-85-2).

[0012] Preferably, the solvent for the oxidation reaction includes one or more combinations of isopropanol, acetone, acetonitrile, methanol, and glacial acetic acid.

[0013] Methanol (CAS: 67-56-1) is more preferred.

[0014] Preferably, the molar ratio of the compound 1 to ozone is 1:2-8.

[0015] More preferably, the ratio is 1:2.5-4.

[0016] Preferably, the molar ratio of the compound 1 to the catalyst is 1:0.01-0.1.

[0017] More preferably, it is 1:0.05 to 0.08.

[0018] Preferably, the mass ratio of the compound 1 to the solvent is 1:2-6.

[0019] More preferably, the ratio is 1:3 to 5.

[0020] Preferably, the ozone for the oxidation reaction is generated on-site by an ozone generator.

[0021] Preferably, the temperature of the oxidation reaction is 50-60°C.

[0022] Preferably, the pressure of the oxidation reaction is 0.6-1.2 MPa.

[0023] Preferably, the oxidation reaction time is 2 to 12 hours.

[0024] More preferably, the time is 5 to 8 hours.

[0025] Beneficial Effects

[0026] (1) The present invention uses ozone as an oxidant to prepare sulfonepyraclostrobin. Since ozone can be decomposed into oxygen at room temperature and pressure, the defect of using hydrogen peroxide as an oxidant and requiring treatment of the hydrogen peroxide solution will not occur. Therefore, the preparation method of the present invention is environmentally friendly and overcomes the defect of harmful emissions.

[0027] (2) The preparation method disclosed in the present invention has high product purity and yield, and the operation process is simple and easy to control. The mother liquor generated during the post-treatment process can be recycled, which is conducive to industrial application.

[0028] (3) The present invention needs to strictly limit the type, amount and material ratio of the raw materials, such as the amount of solvent, the choice of solvent, etc., which have a certain impact on the yield of sulfonepyraclostrobin.

[0029] (4) In the post-treatment process of preparing sulfonepyraclostrobin, the present invention performs a cold filtration step and then performs drying twice, which can further improve the purity and yield of the product.

[0030] (5) The raw material sources of the target product sulfonepyraclostrobin in the present invention are relatively wide, and no complex large-scale process equipment is required during the preparation process, so the production cost is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the target product sulfonepyraclostrobin in Example 1 1 H-NMR spectrum ( 1 H-NMR (400MHz, DMSO) δ7.31 (t, J = 71.7Hz, 1H), 4.71 (s, 2H), 3.85 (s, 3H), 3.20 (s, 2H), 1.44 (s, 6H)). DETAILED DESCRIPTION

[0032] The reaction formulas of the following implementation cases are:

[0033]

[0034] Example 1

[0035] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0036] In the pressure vessel, methanol (150 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (1.36 g, 0.007 mol, 0.05 eq) were added in sequence, the kettle cover was closed, stirring was started, and ozone (16.7 g, 0.348 mol, 2.5 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 50°C at a heating rate of 10°C per hour and the pressure was 0.6 MPa. At this temperature, keep warm for 5 hours; after the reaction is completed, concentrate the reaction liquid, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to keep its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 51.03g of crystalline white solid sulfonepyraclostrobin, with a content of 98.6% and a yield of 92.4%.

[0037] Figure 1 The target product of this example is sulfonepyraclostrobin 1 H-NMR spectrum.

[0038] 1 H-NMR (400MHz, DMSO) δ7.31 (t, J = 71.7Hz, 1H), 4.71 (s, 2H), 3.85 (s, 3H), 3.20 (s, 2H), 1.44 (s, 6H).

[0039] Example 2

[0040] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0041] In the pressure vessel, methanol (200 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (1.64 g, 0.008 mol, 0.06 eq) were added in sequence, the kettle cover was closed, stirring was started, and ozone (20.04 g, 0.417 mol, 3 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 55°C at a heating rate of 10°C per hour and the pressure was 0.8 MPa. At this temperature, keep warm for 6 hours; after the reaction is completed, concentrate the reaction solution, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to keep its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 50.11g of crystalline white solid sulfonepyraclostrobin, with a content of 99.1% and a yield of 91.2%.

[0042] Example 3

[0043] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0044] In the pressure vessel, methanol (250 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (2.18 g, 0.011 mol, 0.08 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (26.72 g, 0.557 mol, 4 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 60°C at a heating rate of 10°C per hour and a pressure of 1.2 MPa. At this temperature, keep warm for 7 hours; after the reaction is completed, concentrate the reaction solution, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 50.02g of crystalline white solid sulfonepyraclostrobin, with a content of 98.2% and a yield of 90.2%.

[0045] Example 4

[0046] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0047] In the pressure vessel, methanol (150 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (1.36 g, 0.007 mol, 0.05 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (20.04 g, 0.417 mol, 3 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 50°C at a heating rate of 10°C per hour and the pressure was 0.7 MPa. At this temperature, keep warm for 5 hours; after the reaction is completed, concentrate the reaction solution, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 50.80g of crystalline white solid sulfonepyraclostrobin, with a content of 98.3% and a yield of 91.7%.

[0048] Example 5

[0049] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0050] In the pressure vessel, methanol (200 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (1.64 g, 0.008 mol, 0.06 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (26.72 g, 0.557 mol, 4 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 55°C at a heating rate of 10°C per hour and a pressure of 1.1 MPa. At this temperature, keep warm for 6 hours; after the reaction is completed, concentrate the reaction solution, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring for crystallization for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 51.23g of crystalline white solid sulfonepyraclostrobin, with a content of 98.1% and a yield of 92.3%.

[0051] Example 6

[0052] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0053] In the pressure vessel, methanol (250 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (2.18 g, 0.011 mol, 0.08 eq) were added in sequence, the kettle cover was closed, stirring was started, and ozone (16.7 g, 0.348 mol, 2.5 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 60°C at a heating rate of 10°C per hour and the pressure was 0.9 MPa. At this temperature, keep warm for 7 hours; after the reaction is completed, concentrate the reaction liquid, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 51.19g of crystalline white solid sulfonepyraclostrobin, with a content of 98.5% and a yield of 90.8%.

[0054] Comparative Example 1

[0055] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0056] In the pressure vessel, isopropanol (200 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (1.36 g, 0.007 mol, 0.05 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (16.7 g, 0.348 mol, 2.5 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 90°C at a heating rate of 10°C per hour and a pressure of 1.4 MPa. At this temperature, keep warm for 8 hours; after the reaction is completed, concentrate the reaction liquid, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to keep its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 44.65g of crystalline white solid sulfonepyraclostrobin, with a content of 97.2% and a yield of 79.7%.

[0057] Comparative Example 2

[0058] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0059] In the pressure vessel, methanol (150 g), compound 1 (50 g, 0.139 mol, 1 eq), titanium dioxide (0.67 g, 0.008 mol, 0.06 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (20.04 g, 0.417 mol, 3 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 55°C at a heating rate of 10°C per hour and the pressure was 0.8 MPa. At this temperature, keep warm for 6 hours; after the reaction is completed, concentrate the reaction solution, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 47.63g of crystalline white solid sulfonepyraclostrobin, with a content of 98.2% and a yield of 85.9%.

[0060] Comparative Example 3

[0061] This example provides a method for preparing sulfonepyraclostrobin, which specifically comprises the following steps:

[0062] In the pressure vessel, methanol (250 g), compound 1 (50 g, 0.139 mol, 1 eq), ammonium molybdate (2.18 g, 0.011 mol, 0.08 eq) were added in sequence, the lid of the kettle was covered, stirring was started, and ozone (13.36 g, 0.278 mol, 2 eq) newly prepared on-site by the ozone generator was introduced. After the ventilation was completed, the system was heated to 50°C at a heating rate of 10°C per hour and a pressure of 0.5 MPa. At this temperature, keep warm for 7 hours; after the reaction is completed, concentrate the reaction liquid, cool the concentrated solution to 8°C at a cooling rate of 5°C per hour, maintain it at 8°C and continue stirring and crystallizing for one hour; put the Buchner funnel into the refrigerator in advance to maintain its temperature at about 8°C, filter the concentrated solution at this temperature to obtain a filter cake; put the filter cake into a forced air drying oven, set the temperature to 50°C and bake it for 2 hours, and then bake it at 80°C for 3 hours to obtain 45.38g of crystalline white solid sulfonepyraclostrobin, with a content of 97.8% and a yield of 81.5%.

Claims

1. A method for preparing sulfonepyraclostrobin, characterized in that: The following steps are involved: At a temperature of 10 to 120°C and a pressure of 0.2 to 1.5 MPa, with ozone as an oxidant and in the presence of a catalyst, compound 1, ozone and a solvent are added in a certain proportion to carry out an oxidation reaction; after the reaction is completed, the reaction solution is cooled for crystallization, filtered and dried to obtain crystalline white solid sulfonepyraclostrobin; the chemical reaction formula of sulfonepyraclostrobin is as follows:

2. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The catalyst includes one or more combinations of manganese dioxide, chromium trioxide, vanadium pentoxide, titanium dioxide, ferric chloride, ammonium molybdate, and sodium periodate.

3. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The solvent includes one or more combinations of isopropanol, acetone, acetonitrile, methanol, and glacial acetic acid.

4. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The molar ratio of the compound 1 to ozone is 1:2-8.

5. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The molar ratio of the compound 1 to the catalyst is 1:0.01-0.

1.

6. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The mass ratio of the compound 1 to the solvent is 1:2-6.

7. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The ozone is generated on-site by an ozone generator.

8. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The temperature of the oxidation reaction is 50-60°C.

9. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The oxidation reaction time is 2 to 12 hours.

10. The method for preparing sulfonepyraclostrobin according to claim 1, characterized in that: The pressure of the oxidation reaction is 0.6-1.2 MPa.

Images