Synthesis method of fluxapyroxad

Abstract

The present invention discloses a fluxapyroxad synthesis method, and relates to the technical field of organic chemical synthesis, and the fluxapyroxad synthesis method comprises: preparing raw materials including fluorinated benzene, an amide source and a solvent; adding a catalyst, and carrying out acylation reaction on fluorinated benzene and an amide source by using an ultrasonic technology to obtain an intermediate; heating the obtained intermediate by microwave radiation, and cyclizing to form fluxapyroxad; separating the fluxapyroxad by using a supercritical fluid extraction method; and carrying out NMR and HPLC analysis on the obtained product, and analyzing the structure and purity of the product. According to the method, the acylation reaction of the fluorinated benzene and the amide source is promoted through the ultrasonic technology, the reaction rate and the reaction conversion rate can be remarkably increased, the synthesis time can be shortened, the fluxapyroxad is separated through the supercritical fluid extraction technology, the influence on the environment is reduced, the supercritical fluid has good dissolving capacity, and the yield of the fluxapyroxad is improved. The target product can be efficiently separated, and meanwhile, waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical synthesis, and in particular to a method for synthesizing fluopyraclostrobin. Background Art

[0002] Fluopyrabamide is a widely used fungicide, mainly used to control fungal diseases in crops. Its effectiveness and importance in agricultural production have made the synthesis method of fluopyrabamide a research hotspot. The molecular structure of fluopyrabamide contains functional groups such as fluorine and nitrogen. These special chemical properties give it excellent biological activity and environmental stability. Traditional fluopyrabamide synthesis methods mainly rely on complex organic reaction processes, often involving multi-step synthesis and strict reaction conditions. These methods not only require high-purity raw materials, but also require control of reaction temperature, pressure and time to ensure the yield and purity of the synthetic products. In addition, the treatment of by-products and wastes that may be generated during the reaction is also an issue that needs to be focused on during the synthesis process.

[0003] The existing synthesis method of flupyraclostrobin is not green and environmentally friendly during the synthesis process, the synthesis efficiency is low, and modern analytical technology cannot be used to monitor and evaluate the synthesis process, so that the controllability of the high synthesis process is not strong. Summary of the invention

[0004] In order to solve the above technical problems, a method for synthesizing fluopyram is provided. The technical solution solves the above problems.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is: A method for synthesizing fluopyrabendazim, the method comprising: preparing raw materials, the raw materials comprising fluorinated benzene, an amide source and a solvent; Adding a catalyst, using ultrasonic technology to carry out acylation reaction between fluorinated benzene and an amide source to obtain an intermediate; The obtained intermediate is heated by microwave radiation to undergo cyclization to form pentafluoropyraclostrobin; Separation of pentopyroxamidine using supercritical fluid extraction; The obtained product was subjected to NMR and HPLC analysis to analyze its structure and purity.

[0006] Preferably, the raw materials include fluorinated benzene, an amide source and a solvent, specifically including: Select 3-fluorobenzoic acid benzene fluoride, select ammonia water as the amide source and select isopropanol as the solvent; Weigh 3-fluorobenzoic acid and ammonia water according to a molar ratio of 1:1.2; In a dry reaction vessel, weighed amounts of 3-fluorobenzoic acid and aqueous ammonia were added, followed by the solvent, and the gas in the mixture was removed using a vacuum pump.

[0007] Preferably, the specific steps of adding a catalyst and using ultrasonic technology to acylate the fluorinated benzene with an amide source to obtain an intermediate are: Prepare a glass reaction bottle and an ultrasonic cleaner, and set the ultrasonic frequency to 20-40kHz; According to the reaction molar ratio, prepare 3-fluorobenzoic acid and ammonia water; The reaction bottle is dried, and the weighed 3-fluorobenzoic acid, ammonia water and solvent are added into the dried reaction bottle and mixed thoroughly; Add the catalyst to the reaction mixture to ensure that the catalyst is fully in contact with the reactants and is evenly dispersed; place the reaction mixture in an ultrasonic device, set the reaction temperature to 50-80°C, and the ultrasonic power to Between 100-300W; Start the ultrasonic equipment and perform ultrasonic treatment, the reaction time is 30 minutes to 1 hour; After the set reaction time is over, the ultrasonic device is turned off and the reaction mixture is cooled; Use liquid extraction separation technology to separate the intermediates generated in the reaction mixture; The isolated intermediate is washed and dried to remove excess solvent and catalyst.

[0008] Preferably, the specific steps of heating the obtained intermediate by microwave radiation to cyclize and form fluopyraclostrobin are: preparing intermediates obtained by previous reactions; Prepare a microwave synthesizer and glass microwave reaction vials; According to the molar ratio of the reaction, the required intermediate is accurately weighed and placed in a glass microwave reaction bottle; Add isopropanol to fully dissolve the intermediate; Adding an appropriate amount of trifluoroacetic acid into the reaction system to promote the cyclization reaction; Set the temperature of the microwave synthesizer between 150-200°C and the irradiation time between 5-30 minutes; Place the glass microwave reaction bottle containing the reaction mixture into the microwave device, start microwave radiation, and monitor the temperature change during the reaction; Samples were taken during the reaction, and thin layer chromatography was used to monitor the progress of the reaction and observe the formation of fluopyraclostrobin; After the set reaction time is over, the microwave equipment is turned off and the reaction system is cooled to room temperature.

[0009] Preferably, the specific steps of separating fluopyrabamide using the supercritical fluid extraction method are: Prepare supercritical fluid extraction equipment and check high-pressure pumps, extractors and temperature control systems; Select samples containing fluopyrabamide and perform pretreatment, including drying and crushing; Select carbon dioxide as the supercritical fluid; Ethanol was added to improve the solubility of fluopyrabdo; Set the extraction conditions, set the temperature of supercritical fluid extraction between 40-80°C and the pressure between 10-30MPa, and perform preliminary experiments to optimize the parameters; Load the pretreated sample into the extractor, ensuring that the sample is evenly distributed; Start the supercritical fluid extraction equipment, first pressurize and heat the carbon dioxide to a set supercritical state; Allowing supercritical fluid to flow through the sample to extract it; During the extraction process, the fluopyram carried by the fluid will flow out with the fluid and will be precipitated from the fluid by reducing the pressure or lowering the temperature.

[0010] Preferably, the extraction conditions are set to set the temperature of supercritical fluid extraction between 40-80°C and the pressure between 10-30MPa, and the specific steps of performing preliminary experimental optimization parameters are: Setting experimental objectives, which include improving extraction efficiency, improving purity and shortening extraction time; Selecting experimental variables, wherein the experimental variables include temperature, pressure, extraction time, extraction rate, product purity and extraction efficiency; Orthogonal experimental design was used to determine the value range of each variable; The specific value range is: Temperature: 40℃, 50℃, 60℃, 70℃, 80℃; Pressure: 10MPa, 15MPa, 20MPa, 25MPa, 30MPa; Extraction time: Select 1 hour, 3 hours, 5 hours, or 8 hours.

[0011] Preferably, the specific steps of the orthogonal experiment are: Check high-pressure pumps, extractors, coolers, collectors and temperature control systems; Take the target sample, dry and crush it; Select appropriate temperature and pressure settings according to the experimental design, and record the specific conditions of each experiment; Before conducting each set of experiments, ensure that the equipment is stable, preheated to the set temperature and pressurized to the set pressure; Extraction is performed at a set temperature and pressure, and the extraction time is set; Monitor pressure and temperature regularly to ensure they remain within set ranges; After the extraction is completed, the pressure and temperature are reduced to return the supercritical fluid to the gas phase or liquid phase, and the extract is collected; Record the extraction efficiency and compound concentration under each experimental condition; Statistical analysis was performed on the extraction results under different experimental conditions to determine the best combination of temperature, pressure and time; Response surface methodology was used to determine the optimal conditions affecting the extraction efficiency; Under optimized conditions, the experiment was repeated to verify the reliability and reproducibility of the results; Summarize the experimental data and analyze the effects of different temperatures and pressures on extraction efficiency; Improvement measures were formulated based on the experimental results to further improve the extraction efficiency.

[0012] Preferably, the obtained product is subjected to NMR and HPLC analysis, and the specific steps of analyzing its structure and purity are: The steps of NMR analysis are as follows: Take 5-10 mg of the product of Fluopyrabactam; Dissolve the sample in the NMR solvent, turn on the NMR instrument and preheat it to ensure the equipment is stable; Set the corresponding frequency and scanning times according to the required measurement parameters; The dissolved sample is placed in an NMR tube and installed in the NMR instrument for data collection.

[0013] Preferably, the HPLC analysis steps are: Take 1-5 mg of the fluopicolide product, dissolve it in the mobile phase, and filter the sample solution using a 0.45 μm filter membrane to remove particles and impurities; Turn on the HPLC instrument and preheat it to ensure the system is stable, set the mobile phase composition, flow rate, column temperature and detection wavelength, and use a C18 reverse phase column for separation; Inject the sample solution into the HPLC system through the injector; Record the chromatogram during the analysis process and observe the peak appearance time and peak area; Compare the retention time of the sample with that of the standard to confirm the presence of fluopyrabendazim; Calculate the concentration of fluopyram in the sample and use the peak area or peak height to perform quantitative analysis with the standard curve; The purity of the product was determined by calculating the ratio of the target peak area to the total peak area.

[0014] Preferably, the molecular structure and corresponding chemical characteristics of fluopyrabamide are confirmed by combining the results of NMR and HPLC; In the NMR spectrum, the number and position of peaks were analyzed to verify the functional groups of fluopyrabamide and their connection mode; Obtain HPLC results to provide product purity information. Products with a purity greater than 95% are high-purity products, while products with unqualified purity require further purification. All analytical results were collated and recorded, including NMR spectra, HPLC chromatograms, and data calculation results.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention proposes that the acylation reaction of fluorinated benzene and an amide source is promoted by ultrasonic technology, so that the reaction rate and reaction conversion rate can be significantly improved, and the synthesis time can be shortened. Microwave radiation heating can uniformly provide energy, so that the cyclization reaction is more efficient. The generated fluopyram has better structural consistency and excellent chemical properties. This heating method can control the reaction conditions and reduce the generation of by-products, thereby improving the quality of the target product. The supercritical fluid extraction technology is used to separate fluopyram, which avoids the use of traditional solvents and reduces the impact on the environment. The supercritical fluid has good dissolving power and can efficiently separate the target product while reducing waste generation, which complies with the principle of green chemistry. The combination of ultrasonic wave, microwave radiation and supercritical fluid extraction and other advanced technologies is helpful to improve the purity and yield of the final product fluopyram. By real-time monitoring and optimization of the reaction process, the generation of by-products can be reduced to the greatest extent. The product is subjected to NMR and HPLC analysis, and the structure and purity of fluopyram can be accurately identified. This detailed analysis ensures the repeatability and reliability of the synthesis, provides important technical support for subsequent industrial production, and can effectively reduce the production cost of fluopyram by optimizing the synthesis process and improving the yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a step flow framework diagram of the present invention. DETAILED DESCRIPTION

[0017] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0018] Reference Figure 1 As shown, a method for synthesizing fluopyrabendazim comprises: preparing raw materials, the raw materials comprising fluorinated benzene, an amide source and a solvent; Adding a catalyst, using ultrasonic technology to carry out acylation reaction between fluorinated benzene and an amide source to obtain an intermediate; The obtained intermediate is heated by microwave radiation to undergo cyclization to form pentafluoropyraclostrobin; Separation of pentopyroxamidine using supercritical fluid extraction; The obtained product was subjected to NMR and HPLC analysis to analyze its structure and purity.

[0019] Further, the raw materials include fluorinated benzene, an amide source and a solvent, specifically including: Select 3-fluorobenzoic acid benzene fluoride, select ammonia water as the amide source and select isopropanol as the solvent; Weigh 3-fluorobenzoic acid and ammonia water according to a molar ratio of 1:1.2; In a dry reaction vessel, weighed amounts of 3-fluorobenzoic acid and aqueous ammonia were added, followed by the solvent, and the gas in the mixture was removed using a vacuum pump.

[0020] Furthermore, the specific steps of adding a catalyst and using ultrasonic technology to acylate the fluorinated benzene with an amide source to obtain an intermediate are: Prepare a glass reaction bottle and an ultrasonic cleaner, and set the ultrasonic frequency to 20-40kHz; According to the reaction molar ratio, prepare 3-fluorobenzoic acid and ammonia water; The reaction bottle is dried, and the weighed 3-fluorobenzoic acid, ammonia water and solvent are added into the dried reaction bottle and mixed thoroughly; Add the catalyst to the reaction mixture to ensure that the catalyst is fully in contact with the reactants and is evenly dispersed; place the reaction mixture in an ultrasonic device, set the reaction temperature to 50-80°C, and the ultrasonic power to Between 100-300W; Start the ultrasonic equipment and perform ultrasonic treatment, the reaction time is 30 minutes to 1 hour; After the set reaction time is over, the ultrasonic device is turned off and the reaction mixture is cooled; Use liquid extraction separation technology to separate the intermediates generated in the reaction mixture; The isolated intermediate is washed and dried to remove excess solvent and catalyst.

[0021] Furthermore, the specific steps of heating the obtained intermediate with microwave radiation to cyclize and form fluopyraclostrobin are as follows: preparing intermediates obtained by previous reactions; Prepare a microwave synthesizer and glass microwave reaction vials; According to the molar ratio of the reaction, the required intermediate is accurately weighed and placed in a glass microwave reaction bottle; Add isopropanol to fully dissolve the intermediate; Adding an appropriate amount of trifluoroacetic acid into the reaction system to promote the cyclization reaction; Set the temperature of the microwave synthesizer between 150-200°C and the irradiation time between 5-30 minutes; Place the glass microwave reaction bottle containing the reaction mixture into the microwave device, start microwave radiation, and monitor the temperature change during the reaction; Samples were taken during the reaction, and thin layer chromatography was used to monitor the progress of the reaction and observe the formation of fluopyraclostrobin; After the set reaction time is over, the microwave equipment is turned off and the reaction system is cooled to room temperature.

[0022] Furthermore, the specific steps of separating fluopyrabamide using the supercritical fluid extraction method are: Prepare supercritical fluid extraction equipment and check high-pressure pumps, extractors and temperature control systems; Select samples containing fluopyrabamide and perform pretreatment, including drying and crushing; Select carbon dioxide as the supercritical fluid; Ethanol was added to improve the solubility of fluopyrabdo; Set the extraction conditions, set the temperature of supercritical fluid extraction between 40-80°C and the pressure between 10-30MPa, and perform preliminary experiments to optimize the parameters; Load the pretreated sample into the extractor, ensuring that the sample is evenly distributed; Start the supercritical fluid extraction equipment, first pressurize and heat the carbon dioxide to a set supercritical state; Allowing supercritical fluid to flow through the sample to extract it; During the extraction process, the fluopyram carried by the fluid will flow out with the fluid and will be precipitated from the fluid by reducing the pressure or lowering the temperature.

[0023] Furthermore, the extraction conditions are set, the temperature of the supercritical fluid extraction is set between 40-80°C, and the pressure is set between 10-30MPa, and the specific steps of performing preliminary experimental optimization parameters are: Setting experimental objectives, which include improving extraction efficiency, improving purity and shortening extraction time; Selecting experimental variables, wherein the experimental variables include temperature, pressure, extraction time, extraction rate, product purity and extraction efficiency; Orthogonal experimental design was used to determine the value range of each variable; The specific value range is: Temperature: 40℃, 50℃, 60℃, 70℃, 80℃; Pressure: 10MPa, 15MPa, 20MPa, 25MPa, 30MPa; Extraction time: Select 1 hour, 3 hours, 5 hours, or 8 hours.

[0024] Furthermore, the specific steps of the orthogonal experiment are: Check high-pressure pumps, extractors, coolers, collectors and temperature control systems; Take the target sample, dry and crush it; Select appropriate temperature and pressure settings according to the experimental design, and record the specific conditions of each experiment; Before conducting each set of experiments, ensure that the equipment is stable, preheated to the set temperature and pressurized to the set pressure; Extraction is performed at a set temperature and pressure, and the extraction time is set; Monitor pressure and temperature regularly to ensure they remain within set ranges; After the extraction is completed, the pressure and temperature are reduced to return the supercritical fluid to the gas phase or liquid phase, and the extract is collected; Record the extraction efficiency and compound concentration under each experimental condition; Statistical analysis was performed on the extraction results under different experimental conditions to determine the best combination of temperature, pressure and time; Response surface methodology was used to determine the optimal conditions affecting the extraction efficiency; Under optimized conditions, the experiment was repeated to verify the reliability and reproducibility of the results; Summarize the experimental data and analyze the effects of different temperatures and pressures on extraction efficiency; Improvement measures were formulated based on the experimental results to further improve the extraction efficiency.

[0025] Furthermore, the obtained product is subjected to NMR and HPLC analysis, and the specific steps of analyzing its structure and purity are as follows: The steps of NMR analysis are as follows: Take 5-10 mg of the product of Fluopyrabactam; Dissolve the sample in the NMR solvent, turn on the NMR instrument and preheat it to ensure the equipment is stable; Set the corresponding frequency and scanning times according to the required measurement parameters; The dissolved sample is placed in an NMR tube and installed in the NMR instrument for data collection.

[0026] Further, the HPLC analysis steps are: Take 1-5 mg of the fluopicolide product, dissolve it in the mobile phase, and filter the sample solution using a 0.45 μm filter membrane to remove particles and impurities; Turn on the HPLC instrument and preheat it to ensure the system is stable, set the mobile phase composition, flow rate, column temperature and detection wavelength, and use a C18 reverse phase column for separation; Inject the sample solution into the HPLC system through the injector; Record the chromatogram during the analysis process and observe the peak appearance time and peak area; Compare the retention time of the sample with that of the standard to confirm the presence of fluopyrabendazim; Calculate the concentration of fluopyram in the sample and use the peak area or peak height to perform quantitative analysis with the standard curve; The purity of the product was determined by calculating the ratio of the target peak area to the total peak area.

[0027] Furthermore, the molecular structure and corresponding chemical characteristics of fluopyrabamide were confirmed by combining the results of NMR and HPLC; In the NMR spectrum, the number and position of peaks were analyzed to verify the functional groups of fluopyrabamide and their connection mode; Obtain HPLC results to provide product purity information. Products with a purity greater than 95% are high-purity products, while products with unqualified purity require further purification. All analytical results were collated and recorded, including NMR spectra, HPLC chromatograms, and data calculation results.

[0028] In summary, the advantages of the present invention are: The acylation reaction of fluorinated benzene with an amide source can significantly increase the reaction rate and reaction conversion rate and shorten the synthesis time. This method can obtain the desired intermediate in a shorter time, which helps to improve the overall synthesis efficiency. Microwave radiation heating can provide energy evenly, making the cyclization reaction more efficient. The generated fluopyrabamide has better structural consistency and excellent chemical properties. This heating method can control the reaction conditions and reduce the generation of by-products, thereby improving the quality of the target product. The use of supercritical fluid extraction technology to separate fluopyrabamide avoids the use of traditional solvents and reduces the impact on the environment. Supercritical fluids have good solubility and can efficiently separate target products while reducing waste generation, which is in line with the principles of green chemistry. Combining advanced technologies such as ultrasound, microwave radiation and supercritical fluid extraction can help improve the purity and yield of the final product, fluopyrabamide. By real-time monitoring and optimization of the reaction process, the generation of by-products can be minimized. NMR and HPLC analysis of the product can accurately identify the structure and purity of fluopyrabendazim. This detailed analysis ensures the repeatability and reliability of the synthesis and provides important technical support for subsequent industrial production. By optimizing the synthesis process and improving the yield, the production cost of fluopyraclostrobin can be effectively reduced. At the same time, the demand for expensive raw materials and traditional solvents is reduced, making the overall synthesis more economical. Due to the high efficiency and environmental friendliness of the synthesis method, it can quickly respond to market demand, enhance the competitiveness of products in the agricultural field, and promote the promotion and application of fluopyram.

[0029] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for synthesizing fluopyrabendazim, characterized in that: The synthesis methods include: preparing raw materials, the raw materials comprising fluorinated benzene, an amide source and a solvent; Adding a catalyst, using ultrasonic technology to carry out acylation reaction between fluorinated benzene and an amide source to obtain an intermediate; The obtained intermediate is heated by microwave radiation to undergo cyclization to form pentafluoropyraclostrobin; Separation of pentopyroxamidine using supercritical fluid extraction; The obtained product was subjected to NMR and HPLC analysis to analyze its structure and purity.

2. The method for synthesizing fluopyrabdo according to claim 1, characterized in that: The raw materials prepared include fluorinated benzene, an amide source and a solvent, and specifically include: Select 3-fluorobenzoic acid benzene fluoride, select ammonia water as the amide source and select isopropanol as the solvent; Weigh 3-fluorobenzoic acid and ammonia water according to a molar ratio of 1:1.2; In a dry reaction vessel, weighed amounts of 3-fluorobenzoic acid and aqueous ammonia were added, followed by the solvent, and the gas in the mixture was removed using a vacuum pump.

3. The method for synthesizing fluopyrabdo according to claim 2, characterized in that: The specific steps of adding a catalyst and using ultrasonic technology to acylate fluorinated benzene with an amide source to obtain an intermediate are: Prepare a glass reaction bottle and an ultrasonic cleaner, and set the ultrasonic frequency to 20-40kHz; According to the reaction molar ratio, prepare 3-fluorobenzoic acid and ammonia water; The reaction bottle is dried, and the weighed 3-fluorobenzoic acid, ammonia water and solvent are added into the dried reaction bottle. Mix thoroughly and evenly; Add the catalyst to the reaction mixture to ensure that the catalyst is fully in contact with the reactants and is evenly dispersed; place the reaction mixture in an ultrasonic device, set the reaction temperature to 50-80°C, and the ultrasonic power to between 100-300W; Start the ultrasonic equipment and perform ultrasonic treatment, the reaction time is 30 minutes to 1 hour; After the set reaction time is over, the ultrasonic device is turned off and the reaction mixture is cooled; Use liquid extraction separation technology to separate the intermediates generated in the reaction mixture; The isolated intermediate is washed and dried to remove excess solvent and catalyst.

4. The method for synthesizing fluopyrabdo according to claim 3, characterized in that: The specific steps of heating the obtained intermediate with microwave radiation to cyclize and form fluopyraclostrobin are as follows: preparing intermediates obtained by previous reactions; Prepare a microwave synthesizer and glass microwave reaction vials; According to the molar ratio of the reaction, the required intermediate is accurately weighed and placed in a glass microwave reaction bottle; Add isopropanol to fully dissolve the intermediate; Adding an appropriate amount of trifluoroacetic acid into the reaction system to promote the cyclization reaction; Set the temperature of the microwave synthesizer to between 150-200°C and the irradiation time to 5-30 minutes; Place the glass microwave reaction bottle containing the reaction mixture into the microwave device, start microwave radiation, and monitor the temperature change during the reaction; Samples were taken during the reaction, and thin layer chromatography was used to monitor the progress of the reaction and observe the formation of fluopyraclostrobin; After the set reaction time is over, the microwave equipment is turned off and the reaction system is cooled to room temperature.

5. The method for synthesizing fluopyrabdo according to claim 4, characterized in that: The specific steps of separating fluopyraclostrobin using the supercritical fluid extraction method are as follows: Prepare supercritical fluid extraction equipment and check high-pressure pumps, extractors and temperature control systems; Select samples containing fluopyrabamide and perform pretreatment, including drying and crushing; Select carbon dioxide as the supercritical fluid; Ethanol was added to improve the solubility of fluopyrabdo; Set the extraction conditions, set the temperature of supercritical fluid extraction between 40-80°C and the pressure between 10-30MPa, and perform preliminary experiments to optimize the parameters; Load the pretreated sample into the extractor, ensuring that the sample is evenly distributed; Start the supercritical fluid extraction equipment, first pressurize and heat the carbon dioxide to a set supercritical state; Allowing supercritical fluid to flow through the sample to extract it; During the extraction process, the fluopyram carried by the fluid will flow out with the fluid and will be precipitated from the fluid by reducing the pressure or lowering the temperature.

6. The method for synthesizing fluopyrabdo according to claim 5, characterized in that: The specific steps of setting the extraction conditions, setting the temperature of supercritical fluid extraction between 40-80°C and the pressure between 10-30MPa, and performing preliminary experimental optimization parameters are as follows: Setting experimental objectives, which include improving extraction efficiency, improving purity and shortening extraction time; Selecting experimental variables, wherein the experimental variables include temperature, pressure, extraction time, extraction rate, product purity and extraction efficiency; Orthogonal experimental design was used to determine the value range of each variable; The specific value range is: Temperature: 40℃, 50℃, 60℃, 70℃, 80℃; Pressure: 10MPa, 15MPa, 20MPa, 25MPa, 30MPa; Extraction time: Select 1 hour, 3 hours, 5 hours, or 8 hours.

7. The method for synthesizing fluopyrabdo according to claim 6, characterized in that: The specific steps of the orthogonal experiment are: Check high-pressure pumps, extractors, coolers, collectors and temperature control systems; Take the target sample, dry and crush it; Select appropriate temperature and pressure settings according to the experimental design, and record the specific conditions of each experiment; Before conducting each set of experiments, ensure that the equipment is stable, preheated to the set temperature and pressurized to the set pressure; Extraction is performed at a set temperature and pressure, and the extraction time is set; Monitor pressure and temperature regularly to ensure they remain within set ranges; After the extraction is completed, the pressure and temperature are reduced to return the supercritical fluid to the gas phase or liquid phase, and the extract is collected; Record the extraction efficiency and compound concentration under each experimental condition; Statistical analysis was performed on the extraction results under different experimental conditions to determine the best combination of temperature, pressure and time; Response surface methodology was used to determine the optimal conditions affecting the extraction efficiency; Under optimized conditions, the experiment was repeated to verify the reliability and reproducibility of the results; Summarize the experimental data and analyze the effects of different temperatures and pressures on extraction efficiency; Improvement measures were formulated based on the experimental results to further improve the extraction efficiency.

8. The method for synthesizing fluopyrabdo according to claim 7, characterized in that: The obtained product is subjected to NMR and HPLC analysis, and the specific steps of analyzing its structure and purity are as follows: The steps of NMR analysis are as follows: Take 5-10 mg of the product of Fluopyrabactam; Dissolve the sample in the NMR solvent, turn on the NMR instrument and preheat it to ensure the equipment is stable; Set the corresponding frequency and scanning times according to the required measurement parameters; The dissolved sample is placed in an NMR tube and installed in the NMR instrument for data collection.

9. The method for synthesizing fluopyrabdo according to claim 8, characterized in that: The HPLC analysis steps are: Take 1-5 mg of the fluopicolide product, dissolve it in the mobile phase, and filter the sample solution using a 0.45 μm filter membrane to remove particles and impurities; Turn on the HPLC instrument and preheat it to ensure the system is stable, set the mobile phase composition, flow rate, column temperature and detection wavelength, and use a C18 reverse phase column for separation; Inject the sample solution into the HPLC system through the injector; Record the chromatogram during the analysis process and observe the peak appearance time and peak area; Compare the retention time of the sample with that of the standard to confirm the presence of fluopyrabendazim; Calculate the concentration of fluopyram in the sample and use the peak area or peak height to perform quantitative analysis with the standard curve; The purity of the product was determined by calculating the ratio of the target peak area to the total peak area.

10. The method for synthesizing fluopyrabdo according to claim 9, characterized in that: Combining the results of NMR and HPLC, the molecular structure and corresponding chemical characteristics of fluopyrabendazole were confirmed; In the NMR spectrum, the number and position of peaks were analyzed to verify the functional groups of fluopyrabamide and their connection mode; Obtain HPLC results to provide product purity information. Products with a purity greater than 95% are high-purity products, while products with unqualified purity require further purification. All analytical results were collated and recorded, including NMR spectra, HPLC chromatograms, and data calculation results.

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