Crystal form of pyroxasulfone and preparation method thereof

Abstract

The invention provides a pyroxasulfone crystal form and a preparation method thereof, and belongs to the technical field of pesticides, the X-ray diffraction pattern of the pyroxasulfone crystal form has characteristic diffraction peaks at the following 2 theta angles: 4.97 degrees, 9.97 degrees, 17.7 degrees, 18.1 degrees, 19.6 degrees, 19.9 degrees, 20.6 degrees, 22.4 degrees, 25.5 degrees and 27.1 degrees, and the error is + / -0.2 degrees. The pyroxasulfone in the molten state is obtained, and the pyroxasulfone in the molten state is transferred and then cooled. The invention provides a pyroxasulfone crystal form and a preparation method thereof. The new crystal form with high purity is obtained through simple steps.

Description

Technical Field

[0001] The invention relates to the technical field of pesticides, and in particular to a crystal form of sulfonepyraclostrobin and a preparation method thereof. Background Art

[0002] Sulfonepyraclostrobin Sulfonepyraclostrobin is a new isoxazole herbicide developed by Kumiai Chemical of Japan. It is a pre-emergence herbicide used for pre-sowing cultivation of dryland field crops such as corn, soybeans and wheat. It has a unique mechanism of action. After being absorbed by embryos and roots, it can interfere with the biochemical synthesis of very long-chain fatty acids in grass cells, prevent cell division, and thus kill harmful weeds. The molecular formula is C 12 H 14 F 5 N 3 O 4 S. pyraclostrobin inhibits the biosynthesis of very long chain fatty acids in plants and shows excellent herbicidal activity against grasses and broadleaf weeds at lower application rates than other commercial herbicides. Pyraclostrobin is a pre-emergence herbicide for controlling grasses and small-seeded broadleaf weeds. In transgenic crop fields, pyraclostrobin controls weeds that are resistant to non-selective herbicides.

[0003] The Chinese patent document with publication number CN114213402A, entitled A metastable and stable crystal form of sulfonepyraclostrobin, preparation method and application, discloses related crystal forms of sulfonepyraclostrobin. The preparation method comprises the following steps: 1. Stirring and heating sulfonepyraclostrobin in a first compound solvent to completely dissolve the solid, cooling and crystallizing, filtering and drying to obtain white fine needle-shaped crystals, which are metastable fine needle-shaped crystal form A; and 2. mixing the metastable fine needle-shaped crystal form A with a second compound solvent in a pressure autoclave, pressurizing under an inert gas atmosphere, maintaining the temperature and pressure, keeping the reactor sealed for reaction, cooling and crystallizing, and filtering and drying after depressurization to obtain translucent columnar crystals B, which are stable columnar crystal form B.

[0004] The Chinese patent document with publication number CN114989157A, entitled A crystalline form A of sulfonepyraclostrobin and its preparation method and application, discloses that sulfonepyraclostrobin solid or a reaction concentrate containing sulfonepyraclostrobin is dissolved in a suitable solvent, and then cooled and crystallized to obtain a new crystalline form.

[0005] However, in both of the above two technical solutions, a single or compound solvent is added to the reaction system to precipitate sulfonepyraclostrobin solid, but the reaction system usually contains impurities, so the purity of the precipitated sulfonepyraclostrobin crystals is not high enough. Summary of the invention

[0006] In view of this, the present invention provides a crystal form of sulfonepyraclostrobin and a preparation method thereof, which can obtain a new crystal form with high purity through simple steps.

[0007] To achieve the above-mentioned purpose, the present invention provides a crystal form of sulfonepyraclostrobin, and the X-ray diffraction pattern of the sulfonepyraclostrobin crystal form has characteristic diffraction peaks at the following 2θ angles: 4.97°, 9.97°, 17.7°, 18.1°, 19.6°, 19.9°, 20.6°, 22.4°, 25.5°, and 27.1°, with an error of ±0.2°.

[0008] Optionally, the X-ray diffraction pattern of the sulfonepyraclostrobin crystal form has characteristic diffraction peaks at the following 2θ angles: 4.97°, 9.97°, 17.7°, 18.1°, 19.6°, 19.9°, 20.6°, 22.4°, 25.5°, and 27.1°.

[0009] Optionally, the X-ray powder diffraction pattern of the sulfonepyraclostrobin crystal form is as follows: Figure 1 shown.

[0010] In order to achieve the above-mentioned purpose, the present invention also provides a method for preparing a crystal form of sulfonepyraclostrobin, wherein the sulfonepyraclostrobin solid is heated to a molten state to obtain sulfonepyraclostrobin in a molten state, and the sulfonepyraclostrobin in a molten state is transferred and then cooled.

[0011] Optionally, the temperature of heating to a molten state is 130-160°C.

[0012] Optionally, the cooling rate is 5-8°C / h; cooling to 25-30°C.

[0013] In order to achieve the above object, the present invention also provides a sulfonepyraclostrobin having the above sulfonepyraclostrobin crystal form for use in herbicides.

[0014] The above technical solution of the present invention includes at least the following beneficial effects: The technical solution provided by the present invention overcomes the problem that the sulfonepyraclostrobin solid is precipitated using a single solvent or a compound solvent, which causes the impurities in the reaction system to precipitate together. The process steps are simple and easy to control, a new crystal form is prepared, and since the impurities in the reaction system will not precipitate, the prepared sulfonepyraclostrobin crystals have high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the X-ray powder diffraction pattern of the sulfonepyraclostrobin crystal prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0016] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will be combined with the appended drawings of the embodiments of the present invention. Figure 1, the technical scheme of the embodiment of the present invention is clearly and completely described. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0017] Example 1 Take a 500mL four-necked bottle, put 200g of sulfonepyraclostrobin solid into it, heat to 130°C until the sulfonepyraclostrobin solid becomes molten, pour out the molten liquid in the four-necked bottle, cool by 5°C per hour for 21 hours, cool to 25°C, put the molten sulfonepyraclostrobin into a pulverizer after it is cooled and solidified, and pulverize it with the pulverizer for 20 minutes to obtain sulfonepyraclostrobin solid powder.

[0018] Example 2 Take a 500mL four-necked bottle, put 200g of sulfonepyraclostrobin solid into it, heat to 158°C until the sulfonepyraclostrobin solid becomes molten, pour out the molten liquid in the four-necked bottle, cool by 8°C per hour for 16 hours, cool to 30°C, put the molten sulfonepyraclostrobin into a pulverizer after it is cooled and solidified, and pulverize it for 15 minutes to obtain sulfonepyraclostrobin solid powder.

[0019] Example 3 Take a 300mL four-necked bottle, put 100g of sulfonepyraclostrobin solid into it, heat to 130°C until the sulfonepyraclostrobin solid becomes molten, pour out the molten liquid in the four-necked bottle, cool by 8°C per hour for 12.5h, cool to 30°C, put the molten sulfonepyraclostrobin into a pulverizer after it is cooled and solidified, and pulverize it for 20min to obtain sulfonepyraclostrobin solid powder.

[0020] Example 4 Take a 300mL four-necked bottle, put 100g of sulfonepyraclostrobin solid into it, heat to 160°C until the sulfonepyraclostrobin solid becomes molten, pour out the molten liquid in the four-necked bottle, cool by 5°C per hour for 27 hours, cool to 25°C, put the molten sulfonepyraclostrobin into a pulverizer after it is cooled and solidified, and pulverize it for 15 minutes to obtain sulfonepyraclostrobin solid powder.

[0021] Example 5 The herbicide comprises 40% of sulfonepyraclostrobin prepared in Example 1, 5% of an organosilicon surfactant, 3% of a wetting and dispersing agent, 2% of a preservative, 3% of a thickener, 1% of a defoaming agent, and water to make up to 100%.

[0022] Comparative Example 1 Compared with Example 5, the only difference is that sulfonepyraclostrobin which has not been cooled after melting according to the present invention is used, and the other raw materials are the same as those in Example 5.

[0023] The herbicides prepared in Example 5 and Comparative Example 1 were subjected to weed control tests: The main types of weeds in the selected test field are crabgrass, barnyard grass, foxtail grass, quinoa, etc. The soil was manually sprayed before the weeds germinated, with a water volume of 45 kg / mu, a plot area of ​​60 square meters, and each treatment was repeated 4 times. The control effect was investigated 45 days after the application of the pesticide. The weed control effect (%) = (the number of weeds in the clear water control area - the number of weeds in the pesticide treatment area) / the number of weeds in the clear water control area. The control effect results are shown in Table 1 below: Table 1 Weed control test results

[0024] As can be seen from Table 1, Example 5 uses pyraclostrobin prepared by the technical solution of the present invention as the herbicide raw material, and the herbicidal effect is better than that of Comparative Example 1.

[0025] The crystal form of sulfonepyraclostrobin prepared in Example was subjected to X-ray diffraction. The X-ray diffraction pattern of sulfonepyraclostrobin obtained in Example 1 is shown in Figure 1 The test values ​​are shown in Table 2.

[0026] Table 2 X-ray diffraction numerical table of sulfonepyraclostrobin in Example 1

[0027] From Table 2 and Figure 1 It can be seen that the crystal form of sulfonepyraclostrobin provided by the present invention has obvious peaks at 4.97°, 9.97°, 17.7°, 18.1°, 19.6°, 19.9°, 20.6°, 22.4°, 25.5°, and 27.1°.

[0028] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A crystal form of sulfonepyraclostrobin, characterized in that: The X-ray diffraction pattern of the sulfonepyraclostrobin crystal has characteristic diffraction peaks at the following 2θ angles: 4.97°, 9.97°, 17.7°, 18.1°, 19.6°, 19.9°, 20.6°, 22.4°, 25.5°, and 27.1°, with an error of ±0.2°.

2. The crystal form of sulfonepyraclostrobin according to claim 1, characterized in that: The X-ray diffraction spectrum of the sulfonepyraclostrobin crystal form has characteristic diffraction peaks at the following 2θ angles: 4.97°, 9.97°, 17.7°, 18.1°, 19.6°, 19.9°, 20.6°, 22.4°, 25.5°, and 27.1°.

3. The crystal form of sulfonepyraclostrobin according to claim 1, characterized in that: The X-ray powder diffraction pattern of the sulfonepyraclostrobin crystal form is shown in FIG1 .

4. The method for preparing the crystal form of sulfonepyraclostrobin according to any one of claims 1 to 3, characterized in that: The sulfonepyraclostrobin solid is heated to a molten state to obtain sulfonepyraclostrobin in a molten state, and the sulfonepyraclostrobin in a molten state is transferred and then cooled and solidified.

5. The method for preparing the crystal form of sulfonepyraclostrobin according to claim 4, characterized in that: The heating temperature to the molten state is 130-160°C.

6. The method for preparing the crystal form of sulfonepyraclostrobin according to claim 4, characterized in that: The cooling rate during the cooling and solidification is 5-8°C / h; cooling to 25-30°C.

7. The sulfonepyraclostrobin as claimed in any one of claims 1 to 3 is used as a herbicide.

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