- Synthesis method of 2, 3-dichloro-5-trichloromethylpyridine
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The invention discloses a synthesis method of 2, 3-dichloro-5-trichloromethylpyridine, which is characterized in that a microreactor is used as a chlorination reaction channel, the first half of the microreactor channel is used as a primary chlorination channel, and the second half of the microreactor channel is filled with a catalyst B as a secondary chlorination reaction channel. The method comprises the following steps of firstly, fully mixing 2-chloro-5-methylpyridine with a catalyst A in a mixing chamber, then continuously reacting with chlorine through a primary chlorination channel to obtain 2-chloro-5-trichloromethylpyridine, then reacting through a secondary chlorination channel to obtain a crude oil layer of 2, 3-dichloro-5-trichloromethylpyridine, and carrying out alkali washing, dechlorination and rectification on the crude oil layer to obtain the high-concentration 2, 3 -dichloro-5-trichloromethylpyridine with the total yield to be 82-93%. According to the method, the technological process is simple, amplification production can be carried out through parallel connection, the catalyst B can be recycled and reused, the chlorination time is remarkably shortened, the chlorine utilization rate is increased, the post-treatment difficulty of the product is reduced, and the synthesis cost of 2, 3-dichloro-5-trichloromethylpyridine is saved.
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Paragraph 0037-0058
(2021/06/13)
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- Method for efficiently synthesizing pyridine chlorides
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The invention discloses a method for efficiently synthesizing a pyridine chloride. The method comprises the following steps: introducing chlorine into methylpyridine in a solvent, and activating witha ligand catalyst; and after the activation is finished, separating and removing the solvent to obtain activated methylpyridine, carrying out a chlorine gas introduction reaction at a certain temperature, and after the reaction is finished, carrying out distillation separation to obtain 2,3-dichloro-5-trichloromethylpyridine. According to the process disclosed by the invention, methylpyridine is firstly activated by adopting an efficient ligand catalyst, then chlorine is introduced for chlorination, the chlorination process has high selectivity, the reaction condition is mild, the equipment operation is simple, few polychlorinated impurities are generated in the reaction process, and the process has high operability and economical efficiency.
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Paragraph 0025; 0028-0030; 0033-0035; 0038-0040; 0043-0045
(2020/06/09)
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- Method for preparing 2, 3, 6-trichloropyridine
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The invention discloses a preparation method of 2, 3, 6-trichloropyridine. The preparation method comprises the following steps: taking 3-methylpyridine and chlorine as raw materials and preparing 2,3, 6-trichloropyridine through catalytic one-step gas-phase chlorination and trichloromethyl removal by a molecular sieve catalyst in the presence of water vapor. The molecular sieve catalyst is prepared by taking raw molecular sieve powder as an active component. The raw material 3-methylpyridine adopted in the invention is a byproduct in the synthesis of pyridine by an aldehyde ammonia method, and the source is cheap and easy to obtain. The molecular sieve catalyst has strong treatment capacity, the 3-methylpyridine and the chlorine are used as the raw materials, a proper amount of water isadded, gas-phase chlorination and trichloromethyl removal reactions are carried out under the action of a molecular sieve acid center and water vapor molecules, and the 2, 3, 6-trichloropyridine is synthesized by one step. The process is simple, the product purity and conversion rate are high, the yield can be maintained at 85% or above generally, the maximum yield can reach up to 95%, and the preparation method of the 2, 3, 6-trichloropyridine has good industrial application prospect.
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Paragraph 0054; 0055
(2019/05/22)
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- Synthetic method of 2,3-dichloro-5-trichloromethyl pyridine
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The invention provides a preparation method of 2,3-dichloro-5-trichloromethyl pyridine. The preparation method comprises the following steps: carrying out chlorination reaction on 2-chloro-5-chloromethyl pyridine and a chlorination reagent at 1-8 atm at the temperature of 100-250 DEG c in the presence of a catalyst, and distilling to obtain the 2,3-dichloro-5-trichloromethyl pyridine; the preparation method disclosed by the invention has the advantages that raw materials are cheap, the operation is simple, the post-treatment is convenient, the purity and the yield are relatively high, and large-scale industrial production can be carried out. The used catalyst is oxides, chlorides or chlorine oxides of manganese, iron, cobalt and ruthenium. No solvent is added, and the use amount of the catalyst is small. The mixed catalyst is used to avoid excessive use of a single expensive catalyst, and the catalyst can be recycled. Effective components in the residues can be extracted, and waste isavoided. The method disclosed by the invention has the advantages that the reaction window is wide, and the intermediate which is not completely converted can be distilled out and can be continuouslyused.
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Paragraph 0020-0021; 0022; 0023; 0025
(2019/07/04)
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- A 2 - chloro -5 - nitrapyrin preparation method
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The invention discloses a 2 - chloro - 5 - trichloromethyl pyridine method, comprises the following steps: (1) the 3 - methyl pyridine is mixed with a solvent, the vaporization of the drops in the vaporization vessel, then in order to inert gas as a carrier gas, to form raw material steam; (2) dry Cl respectively2 The raw material and the steam is sent to the quartz tube catalyst [...] generating vapor phase chlorination reaction, reaction material after the condensation, rectification to obtain 2 - chloro - 5 - trichloromethyl pyridine. The invention relates to a 2 - chloro - 5 - trichloromethyl pyridine method, with raw materials are easy, low cost, easy to operate, simple process and the like.
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Paragraph 0031-0032
(2019/03/15)
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- Preparation method of 2-fluorine-3-chlorine-5-trifluoromethylpyridine
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The invention relates to the technical field of chemical synthesis, and in particular discloses a preparation method of 2-fluorine-3-chlorine-5-trifluoromethylpyridine. The preparation method of the 2-fluorine-3-chlorine-5-trifluoromethylpyridine is characterized by comprising the following steps: taking 2-chlorine-5-trichloromethylpyridine as a raw material, taking tungsten hexachloride as a catalyst, heating and introducing chlorine to perform chlorination reaction, thereby obtaining 2,3-dichloro-5-trichloromethylpyridine; putting the 2,3-dichloro-5-trichloromethylpyridine into a fluorination kettle, adding antimony pentafluoride and anhydrous hydrogen fluoride, stirring and heating to perform reaction, cooling after reaction, washing with water, layering, feeding to a rectification kettle, and performing reduced-pressure rectification, thereby preparing the 2-fluorine-3-chlorine-5-trifluoromethylpyridine. The process is reliable, the raw materials are sufficient in the market and easily available, and the preparation method of the 2-fluorine-3-chlorine-5-trifluoromethylpyridine is low in production cost, simple in operation, high in yield and favorable for large-scale production.
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Paragraph 0026; 0031; 0034
(2018/07/30)
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- Synthesis method of chlorfluazuron and application of chlorfluazuron in insecticide preparation
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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.
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Paragraph 0030; 0032; 0033; 0035
(2017/07/21)
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- 2. 3 - dichloro -5 - trifluoro methyl pyridine preparation method
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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.
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Paragraph 0021; 0022
(2017/06/13)
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- A METHOD FOR PRODUCING 2,3-DICHLORO-5-(TRICHLOROMETHYL)PYRIDINE
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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.
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- Vapor phase catalytic chlorination of ?-picoline
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2-Chloro-5-trichloromethylpyridine is obtained by chlorinating β-picoline in the vapor phase using a Mordenite zeolite or a supported palladium catalyst.
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Page/Page column 3-4
(2008/06/13)
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- Recovery of catalysts as W, Mo or Ru oxychlorides in liquid phase chlorination of pyiridine compounds
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Metal chloride catalysts employed in liquid phase chlorination reactions are recovered by treating the reaction mass with oxygen or air to form solid metal oxychloride compounds which can be separated and reused.
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- SOME NEW 2-SUBSTITUTED 5-TRIFLUOROMETHYLPYRIDINES
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The preparation of the derivatives of 2-amino-, hydrazino-, hydroxy-, and mercapto-5-trifluoromethylpyridines via 2-chloro precursors is describes.Experimental and spectral data of the products together with those of the precursors are presented.
- Haga, Takahiro,Fujikawa, Kan-ichi,Koyanagi, Tohru,Nakajima, Toshio,Hayashi, Kouji
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p. 117 - 124
(2007/10/02)
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- Process for the production of chloropyridines substituted by methyl, trichloromethyl or trifluoromethyl groups
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Chloropyridines of the formula STR1 wherein either R is chlorine and R' is methyl or trifluoromethyl, or R is methyl, trichloromethyl or trifluoromethyl and R' is chlorine, or R and R' are methyl, can be obtained by a novel, simple process by the addition of trichloroacetaldehyde to methacrylonitrile or α-trifluoromethacrylonitrile, 2,2-dichloropropionaldehyde, pentachloropropionaldehyde or 2,2-dichloro-3,3,3-trifluoropropionaldehyde to acrylonitrile, or 2,2-dichloropropionaldehyde to methacrylonitrile, in the presence of a catalyst, in particular copper powder or copper(I) chloride, and cyclizing the open-chain intermediate obtained. The chloropyridines of the formula (I) are known per se and are suitable for the production of different compounds, in particular of insecticides and herbicides.
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- Production of polychlorinated pyridine mixtures by liquid phase chlorination of beta-picoline or beta-picoline hydrochloride
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Preparation of high yields of mixtures rich in polychlorinated pyridines by maintaining a chlorine to beta-picoline weight ratio of greater than about 5:1 when reacting chlorine and beta-picoline or beta-picolie hydrochloride non-catalytically in the liquid phase at temperatures of at least about 190° C., the reactants being contained in a well mixed diluent producing less than one mole of hydrogen chlorine per mole of diluent by reaction with the chlorine in the indicated temperature range. Chlorination of the beta-picoline or beta-picoline hydrochloride in a primary reactor is followed by selective further chlorination thereof in finishing reactor means at a temperature of at least about 190° C. to obtain high yields of desired final products useful as intermediates in the formation of herbicides and the like. Like further chlorination to obtain such final products is also applicable to mixtures rich in monochloro-, dichloro-, and trichloro-3-trichloromethyl pyridines produced by other processes.
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- Method for converting carboxylic acid groups to trichloromethyl groups
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Method for converting carboxylic acid groups to trichloromethyl groups which comprises contacting a compound containing a carboxylic acid group with a phenylphosphonic dichloride and phosphorus pentachloride and recovering the thus produced product.
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- Herbicidal pyridine compounds
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Herbicidal 3- and/or 5-halogenomethyl-pyrid-2-yloxyphenoxy compounds and processes for making and using the same. Intermediates for making these compounds and their preparation are also disclosed. Thus, for example, 2-chloro-5-trichloromethylpyridine is prepared by a liquid phase chlorination of 3-methylpyridine under the influence of ultra violet light.
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- Herbicidal compounds
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A herbicidal sulphonamide compound of the formula (I): STR1 and salts thereof, wherein R1 is a pyridyl group of the formula: STR2 wherein the group X of the pyridyl group represents a fluorine, chlorine, bromine, or iodine atom, or an alkyl radical of 1 to 4 carbon atoms optionally substituted by one or more fluorine or chlorine atoms, and the group Y represents hydrogen, fluorine chlorine, bromine, or iodine or an alkyl radical of 1 to 4 carbon atoms optionally substituted by one or more fluorine or chlorine atoms; R2 represents an alkyl radical of 1 to 6 carbon atoms optionally substituted by one or more fluorine atoms; and R3 is hydrogen or an alkyl radical of 1 to 4 carbon atoms.
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- Herbicidal mono- or di-substituted-2-pyridinyloxy-phenoxy-lower-alkane-carbamates
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Herbicidal pyridine compounds of the formula (I): STR1 wherein Z may be halogen, or a fluorine- or chlorine-substituted alkyl group of 1 to 4 carbon atoms, and Y may be hydrogen, halogen, or a fluorine- or chlorine-substituted alkyl group of 1 to 4 carbon atoms; X may be an OH group or an acyloxy group; a halogen atom; an amino group, a mono- or di-alkyl amino group, or an alkanoylamido group; an alkoxy group optionally substituted by hydroxy or alkoxy; or a mercapto group, an alkylthio group, or a phenylthio group. The invention also provides herbicidal compositions containing the compounds, and processes for making the compounds.
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