69045-84-7Relevant articles and documents
Preparation method of 2, 3-dichloro-5-trifluoromethylpyridine
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Paragraph 0025-0038, (2021/08/14)
The invention discloses a preparation method of 2, 3-dichloro-5-trifluoromethylpyridine, and belongs to the technical field of organic synthesis. The comprises the following steps: (1) adding 2, 3-dichloro-5-trichloromethylpyridine into an organic solvent under the condition of 20 to 50 DEG C, so as to obtain an organic solution of 2-chloro-5-trichloromethylpyridine; (2) adding fluorinated quaternary ammonium salt and 1, 2-dicyanotetrafluorobenzene into the organic solution of the 2, 3-dichloro-5-trichloromethylpyridine obtained in the step (1), and uniformly mixing to obtain a reaction system; 3) controlling the temperature of the reaction system to be 30-60 DEG C, and reacting to obtain 2, 3-dichloro-5-trifluoromethylpyridine; and 4) filtering the reaction liquid, and carrying out reduced pressure distillation on the obtained filtrate to obtain the 2, 3-dichloro-5-trifluoromethylpyridine. The method can be completed in one step, cheap fluorinated quaternary ammonium salt is selected as a fluorination reagent, and operation is easy; the raw materials are cheap and easily available, the reaction temperature is low, the reaction time is short, and conditions such as high-temperature, high-pressure and dangerous hydrogen fluoride raw materials are avoided; and the yield of the obtained product is 70-90%, and the gas chromatography detection purity is greater than 99.0%.
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%.
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.
METHOD FOR PREPARING 2,3-DICHLORO-5-TRIFLUOROMETHYLPYRIDINE WITH HIGH SELECTIVITY
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Paragraph 0147-0149; 0151-0153; 0156-0157; 0159; 0161, (2020/04/24)
The present invention discloses a method for preparing 2,3-dichloro-5-trifluoromethylpyridine, comprising at a temperature of 100?150° C. and a pressure of 0.5?5.0 MP, in presence of at least one catalyst selected from supported metal chloride, supported zeolite molecular sieve and supported heteropolyacid, 2-chloro-5-trifluoromethylpyridine reacts with chlorine gas to obtain 2,3-dichloro-5-trifluoromethylpyridine. The preparing method provided by the present invention has advantages such as high selectivity of desired product, high utilization rate of chlorine gas, moderate process condition, simple operation and less three wastes. The present invention also discloses a preparing method for preparing 2-chloro-5-trifluoromethylpyridine, which is capable of reducing unit consumption, reducing separation cost, and improving safety compared to the prior art.
Synthetic method of 2,3-dichloro-5-trifluoromethylpyridine
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Paragraph 0023; 0024; 0025; 0025; 0026-0030, (2017/04/29)
The invention discloses a synthetic method of 2,3-dichloro-5-trifluoromethylpyridine. The method comprises the following steps that 1,2,3-dichloro-5-trichloromethylpyridine and hydrogen fluoride are subjected to a halogen exchange reaction at the temperature of 140-200 DEG C under the action of a catalyst; 2, the product obtained after the halogen exchange reaction is heated at the pressure of 0.15-1.0 MPa for a pressurizing conversion reaction, and 2,3-dichloro-5-trifluoromethylpyridine is obtained. According to the method, 1, 2,3-dichloro-5-trichloromethylpyridine and hydrogen fluoride are used for the reaction; the method is characterized in that under catalysis of the catalyst, trichloromethylpyridine reacts with hydrogen fluoride, the reaction is carried out at normal pressure at first, then the conversion reaction is carried out under certain pressure and temperature, and therefore the defect that in a traditional process, it is dangerous because a reaction is carried out at high temperature and high pressure is overcome. According to the process, reaction conditions are mild, dangerousness is low, a small quantity of waste gas, waste water and waste solids are produced, and separation is easy.
Synthesis method of chlorfluazuron and application of chlorfluazuron in insecticide preparation
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Paragraph 0030; 0032; 0033; 0036, (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.
2. 3 - dichloro -5 - trifluoro methyl pyridine preparation method
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Paragraph 0021; 0022, (2017/06/13)
The invention provides a preparation method of 2,3-dichloro-5-trifluoromethylpyridine. The preparation method comprises the following steps: (a) 2-chloro-5-chloromethyl pyridine is provided; (b) in the presence of a catalyst, 2-chloro-5-chloromethyl pyridine from the step (a) and a chloride agent chlorine undergo a chlorination reaction so as to obtain 2,3-dichloro-5-trichloromethylpyridine, wherein the catalyst is oxide of copper, chloride of copper or a combination of the oxide of copper and the chloride of copper; (c) after heated and dissolved, 2,3-dichloro-5-trichloromethylpyridine obtained from the step (b) undergoes a fluoridation reaction with hydrogen fluoride under the action of a catalyst so as to obtain 2,3-dichloro-5-trifluoromethylpyridine, wherein the catalyst is oxide of antimony or halide of antimony. By the above method, production cost is reduced, conversion rate is raised, and toxicity is decreased.
A METHOD FOR PRODUCING 2,3-DICHLORO-5-(TRICHLOROMETHYL)PYRIDINE
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Page/Page column 8; 9; 12, (2015/01/09)
The present invention relates to a novel process for producing of 2,3-dichloro-5-(trichloromethyl)pyridine by using PCl as chlorinating agent at elevated temperature and pressure.
Pyridyl(oxy/thio)phenoxy compounds herbicidal compositions and methods
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, (2008/06/13)
Certain novel pyridinyloxyphenoxy alkanoic acids, pyridinylthiophenoxy alkanoic acids, derivatives thereof and related compounds are described. More specifically, these novel compounds bear a fluorine substituent in the 3-position of the pyridinyl group and in the 5-position the substituent is selected from chlorine, CF3, CF2 Cl or CF2 H. These novel compounds exhibit surprising preemergent and postemergent activity in the control of grassy weeds.
Certain pyridyloxy or thio-phenoxy-propanoic acids or salts thereof useful as herbicides
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, (2008/06/13)
Certain novel pyridinyloxyphenoxy alkanoic acids, pyridinylthiophenoxy alkanoic acids, derivatives thereof and related compounds are described. More specifically, these novel compounds bear a fluorine substituent in the 3-position of the pyridinyl group and in the 5-position the substituent is selected from chlorine, CF3, CF2 Cl or CF2 H. These novel compounds exhibit surprising preemergent and postemergent activity in the control of grassy weeds.
