- Synthetic method 2 -methylsulfonyl -5 - trifluoromethyl -1 , 3, 4 - thiadiazole
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The invention belongs to the technical field of medical intermediates, and particularly relates to a synthetic method 2 -methylsulfonyl -5 - trifluoromethyl -1 , 3, 4 - thiadiazole. To the invention, hydrazine hydrate and carbon disulfide are subjected to addition reaction, and then under basic conditions, dimethyl sulfate is replaced to obtain the intermediate material A, and the intermediate material A is obtained. The intermediate material B is obtained by reacting the intermediate material B with hydrogen peroxide to obtain 2 - methylsulfonyl -5 - trifluoromethyl -1 , 3, 4 - thiadiazole, the operation is simple, the operation is easy, and the yield is high.
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Paragraph 0011
(2021/10/20)
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- Flufenacet preparation method
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The invention discloses a flufenacet preparation method, which comprises synthesis of 2-methylsulfonyl-5-trifluoromethyl-1,3,4-thiadiazole, synthesis of 2-hydroxy-N-(4-fluoroaniline)-N-(1-methylethyl)acetamide and synthesis of 4'-fluoro-N-isopropyl-2-[5-(trifluridine)-1,3,4-thiadiazole-2-imide]acetamide. The optimal flufenacet preparation method is screened by a large number of experiments, the whole process is reasonable in design, particularly the steps of screening optimal reaction conditions and the optimal amount ratio, reaction temperature, reaction time and the like of reaction raw materials, the reaction yield (capable of reaching 90 percent or more) can be greatly increased, side reaction can be reduced, the reaction rate can be increased, the reaction raw materials can be recycled, the production cost is greatly reduced, and a broad application prospect is achieved.
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Paragraph 0033-0035
(2018/04/03)
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- Synthesis method of flufenacet thiadiazole intermediate as herbicide
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The invention discloses a synthesis method for preparing 2-mesyl-5-trifluoromethyl-1,3,4-thiadiazole from 2-methylthio-5-trifluoromethyl-1,3,4-thiadiazole by utilizing microwave ultrasonic waves. Compared with the prior art, the synthesis method provided by the invention has the advantages of saving reaction time, improving equipment and space utilization rate, improving reaction efficiency and increasing the intrinsic safety of the process.
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Paragraph 0028
(2017/07/20)
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- Synthetic method of 2-methylsulfuryl-5-trifluoromethyl-1,3,4-thiadiazole
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The invention belongs to the field of organic synthesis, belongs to pesticide synthesis technologies, and in particular relates to a synthetic method of 2-(methylsulfuryl)-5-(trifluoromethyl)-1,3,4-thiadiazole. According to the synthetic method, 2-( methylthio)-5-(trifluoromethyl)-1,3,4-thiadiazole is used as a raw material, and a phase transfer catalyst and sodium tungstate are selected as catalysts for reaction to prepare a target product. According to the method, a reaction environment is optimized, and the reaction efficiency is greatly improved on the premise of not adding an organic solvent, so that the purity and the yield of the product are improved, the reaction temperature is lowered, the risk of oxydol high-temperature backflow zone water is reduced, and then the safety of the reaction is improved.
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Paragraph 0014; 0028-0039
(2017/08/28)
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- Method for preparing herbicide flufenacet intermediate TDA-sulfone
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The invention discloses a continuous flow synthetic method for preparing 2-methylsulfonyl-5-trifluoromethyl-1,3,4-thiadiazole by oxidizing 2-methylthio-5-trifluoromethyl-1,3,4-thiadiazole. Compared with the prior art, the reaction time is shortened from the conventional 9-11 hours to few minutes, and the reaction efficiency is significantly improved; and the reaction adopts continuous flow, so that the accumulation of a large amount of peroxides at a high reaction temperature is avoided, and the inherent safety of the process is improved.
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Paragraph 0027; 0028; 0029; 0030; 0031; 0032; 0034-0036
(2017/07/20)
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