69045-84-7Relevant articles and documents
Preparation method of 2,3-dichloro-5-trifluoromethylpyridine
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Paragraph 0050; 0073-0079, (2021/10/27)
The invention provides a preparation method of 2,3-dichloro-5-trifluoromethylpyridine. The method comprises the following steps: carrying out condensation and acidification on 1, 1, 1-trifluoroacetone and nitromethane under the action of alkali to obtain 1-nitro-2-trifluoromethyl propylene; the method comprises the following steps: condensing 1-nitro-2-trifluoromethyl propylene and oxalic acid diester under the action of alkali, and carrying out reduction-cyclization reaction and acidification reaction on the obtained reaction liquid in the presence of a catalyst without separation to obtain a product 2, 3-dihydroxy-5-trifluoromethylpyridine; and then subjecting the 2,3-dihydroxy-5-trifluoromethylpyridine and a chlorination reagent to a chlorination reaction to obtain the 2,3-dichloro-5-trifluoromethylpyridine. The raw materials used in the invention are cheap and easily available, and the reaction selectivity of each step is high. The process does not need special equipment to carry out high-temperature chlorination and high-temperature fluorination reactions and is easy to operate, the target product is high in yield and purity, and the process is suitable for industrial production.
Preparation method 2-3 - dichloro -5 - trifluoromethylpyridine
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Paragraph 0024-0033, (2021/10/27)
The invention relates to the technical field of organic synthesis, and discloses a preparation method of 2-3 - dichloro -5 - trifluoromethylpyridine, which comprises the following steps: 1) adding 20 - 50 °C, 2 dichloro 3 -methylpyridine into an organic solvent under -5 - conditions to obtain 2 - chloro -5 - trifluoromethylpyridine. 2) To step (1), the organic solution of 2, 3 - dichloro -5 -methylpyridine was added with a fluorinated quaternary ammonium salt, followed by homogeneous mixing, followed by a reaction system. The method provided by 3) has the advantages of cheap and easily available raw materials, 3 - low -5 - reaction temperature and short time, avoids the use of high temperature and high pressure 20 - 50 °C dangerous hydrogen fluoride raw materials and the like, and finally obtains the product yield and of 2 - 6h . and the gas chromatography detection purity is 99.0% greater than 2 70 - 90%.
Synthesis method of chlorfluazuron and application of chlorfluazuron in insecticide preparation
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, (2017/07/21)
The invention belongs to the technical field of pesticide preparations, particularly relates to a synthesis method of chlorfluazuron and further discloses an application of chlorfluazuron in insecticide preparation. According to the synthesis method of chlorfluazuron, chlorfluazuron is prepared from 2,3-dichloro-5-(trifluoromethyl)pyridine, 2,6-dichloro-4-aminophenol and 2,6-difluorobenzoyl isocyanate as synthetic raw materials and N,N-dimethylacetamide as a reaction solvent on the basis of a conventional synthesis route in the prior art; under the action of a ZSM molecular sieve based catalyst, not only can synthesis of chlorfluazuron be realized, but also a reaction can be performed with the same reaction solvent, so that the problem of complicated process caused by the fact that solvents are required to be recovered step by step during two-step synthesis of chlorfluazuron in the prior art is solved; compared with the technology in the prior art, the synthesis method of chlorfluazuron has the advantages that the synthesis yield of products is further increased and product content is higher.
