- Eine neue, einfache Synthese von 2,3,5-Trichlorpyridin
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A simple synthesis of 2,3,5-trichloropyridine by the copper-catalyzed free radical addition of chloral to acrylonitrile with or without isolation of the primary 1:1 adduct, 4-formyl-2,4,4-trichlorobutyronitrile (1), is described.
- Steiner, Eginhard,Martin, Pierre,Bellus, Daniel
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- Direct formation of 2,3,5-trichloropyridine and its nucleophilic displacement reactions in ionic liquid
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Reaction of trichloroacetaldehyde and acrylonitrile in the presence of a catalytic amount of copper (I) chloride in ionic liquid afforded 2,3,5-trichloropyridine, fluprination of which with KF and CsF in ionic liquid afforded 3,5-dichloro-2-fluoropyridihe and 5-chloro-2,3-dichloropyridine. Reaction of 2,3,5-trichloropyridine, 3,5-dichloro-2-fluoropyridine, or 5-chloro-2,3-dichloropyride with 2-(4-hydroxyphenoxy) propionates in ionic liquid afforded the corresponding 2-aryloxylpropionates in good yields.
- Zhong, Ping,Hu, Huanan,Guo, Shengrong
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- Halopyridines. I. Synthesis of 3,5-Dichloro-2-pyridone and 2,3,5-Trichloropyridine
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Trichloroacetonitrile reacts with acrolein to give 2,2,4-trichloro-5-oxopentanonitrile, the cyclization of which to chloropyridines has been examined.
- Shvekhgeimer, M.-G. A.,Kobrakov, K. I.,Sychev, S. S.,Promonenkov, V. K.
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Read Online
- Synthesis method of 2, 3, 5-trichloropyridine
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The invention relates to a synthesis method of 2, 3, 5-trichloropyridine. The method comprises the following steps: (1) in the presence of a phase transfer catalyst and a polymerization inhibitor, carrying out chemical reaction on trichloroacetaldehyde, acrylonitrile and the catalyst at 60-90 DEG C to prepare an intermediate product 2, 4, 4-trichloro-4-formyl butyronitrile; and (2) heating a reaction solution obtained in the step (1) to 60-100 DEG C, and slowly introducing hydrogen chloride gas into the reaction solution to carry out cyclization reaction, thereby preparing the target compound2, 3, 5-trichloropyridine. The synthesis method has the advantages of mild reaction conditions, no need of harsh reaction conditions, such as high temperature, high pressure and reaction solvent, recyclable catalyst, less heavy metal pollution, high target product yield (up to 80%), high purity (up to 99%), simple post-treatment of the product, and reduced cost, and is suitable for industrial production.
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Paragraph 0011; 0032-0047
(2021/01/25)
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- Continuous production process of 2, 3, 5-trichloropyridine
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According to a continuous production process of 2, 3, 5-trichloropyridine, a continuous tubular chlorinator is adopted, pyridine is taken as a starting raw material, chlorination reaction is continuously carried out step by step by virtue of a catalyst 1 and a catalyst 2 which are independently researched and developed, and 2, 5-dichloropyridine and 2, 3, 5-trichloropyridine are prepared in sequence. In the preparation process of a catalyst 1 and a catalyst 2, the mass ratio of 1-chloropropane to imidazole to 2-chloroethyl diphenylphosphine to nickel tetracarbonyl is 1.2: 1: 3.7: 2.5, and the mass ratio of 1-chloropropane to imidazole to 2-chloroethyl diphenylphosphine to sodium hexachlororhodate hydrate is 1.2: 1: 3.7: 15. By means of the continuous tubular chlorinator, cheap and easily available pyridine is used as a starting raw material, chlorine atoms are introduced step by step through catalytic chlorination, the atom economy is good, the reaction selectivity is good, the yield of 2, 3, 5-trichloropyridine can be stabilized at 80% or above, the production efficiency is high, the process is easy to control, and the method is environmentally friendly and suitable for industrial production.
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Paragraph 0015-0017; 0018-0020
(2021/10/30)
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- Preparation method of 2, 3, 5-trichloropyridine
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The invention relates to the field of organic synthesis, in particular to a preparation method of 2, 3, 5-trichloropyridine. According to the invention, in a mixed solvent composed of an organic solvent and water, 2, 3, 4, 5-tetrachloropyridine is reduced by using zinc powder, such that 2, 3, 5-trichloropyridine is prepared. The preparation method of 2, 3, 5-trichloropyridine has the advantages ofhigh yield and high purity, and is environment-friendly, simple and convenient to operate.
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Paragraph 0019-0042
(2020/11/23)
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- Resourceful treatment method of picloram solid residues
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The invention relates to a picloram solid residue resourceful treatment method which comprises the following steps: a) carrying out decarboxylation reaction on picloram solid residues, performing filtering, taking filtrate, and separating out solid; b) sequentially carrying out diazotization and chlorination reaction on the solid obtained in the step a), separating out the solid, performing filtering, taking a filter cake, and performing separating to obtain 2, 3, 4, 5-tetrachloropyridine; c) subjecting the 2, 3, 4, 5-tetrachloropyridine obtained in the step b) to a dechlorination reaction soas to obtain 2, 3, 5-trichloropyridine and/or 2, 5-dichloropyridine. According to the resourceful treatment method provided by the invention, the picloram solid residues can be converted into 2, 3, 5-trichloropyridine products with good market demand prospects and relatively high economic values, and further efficient utilization of the picloram solid residues is realized.
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Paragraph 0065-0068; 0073-0096
(2020/11/23)
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- Method for preparing 2,3,5-trichloropyridine from 2,3,5,6-tetrachloropyridine
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The invention discloses a method for preparing 2,3,5-trichloropyridine from 2,3,5,6-tetrachloropyridine. The method comprises the following steps: (1) adding 2,3,5,6-tetrachloropyridine, an organic solvent, a catalyst, an acid-binding agent and water input a high-pressure kettle, performing nitrogen displacement for three times, further performing hydrogen displacement for three times, and performing a reaction in a hydrogen atmosphere, wherein the catalyst is prepared from at least one of Pd and Pt as active components and aluminum oxide or activated carbon as a carrier; (2) performing cooling to the room temperature, discharging gases in the high-pressure kettle, performing nitrogen displacement for three times, filtering the reaction product so as to obtain a catalyst, and performing standing and layering on filtrate so as to obtain an organic phase; and (3) performing vacuum distillation on the organic phase so as to obtain a light yellow solid, that is, 2,3,5-trichloropyridine, and recycling the fraction for later use. The 2,3,5,6-tetrachloropyridine which is easy to purchase is adopted as a raw material of the method disclosed by the invention, the method is green and environment-friendly, and in addition the product is high in yield and high in purity.
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Paragraph 0016-0024
(2019/12/25)
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- Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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A convenient and efficient method for the synthesis of 2-halogen-substituted pyridines is described. The decarboxylative halogenation of 2-picolinic acids with dihalomethane proceeded smoothly via N-chlorocarbene intermediates to afford 2-halogen-substituted pyridines in satisfactory to excellent yields under transition-metal-free conditions. This new type of decarboxylative halogenation is operationally simple and exhibits high functional-group tolerance.
- Zhang, Xitao,Feng, Xiujuan,Zhang, Haixia,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 5565 - 5570
(2019/10/22)
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- Method for preparing 2,3,5-trichloropyridine
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The invention relates to the field of compound preparation, and discloses a method for preparing 2,3,5-trichloropyridine, wherein the method comprises the following steps: a. in the presence of a chlorination catalyst, a compound A is contacted with chlorine for chlorination reaction to obtain a mixture containing the 2,3,5-trichloropyridine and 2,3,4,5-tetrachloropyridine; b. the mixture obtainedin the step a is contacted with hydrogen in the presence of a hydrogenation catalyst and a solvent to carry out catalytic hydrogenation reaction; or, the 2,3,5-trichloropyridine and the 2,3,4,5-tetrachloropyridine in the mixture obtained in the step a are separated, the separated 2,3,4,5-tetrachloropyridine is contacted with the hydrogen for catalytic hydrogenation reaction; wherein the compoundA is 2-chloropyridine and / or 2-chloropyridine hydrochloride. The raw materials in the method are simple and easy to obtain, the operating conditions are mild, the product yield is high, the cost islow, the pollution is small, and the method is suitable for large-scale application.
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Paragraph 0057; 0061; 0062; 0067; 0068; 0074; 0075-0078
(2018/09/08)
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- Method for preparing 2, 3, 5-trichloropyridine on basis of layered manganese oxide catalysts with nanometer zinc
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The invention provides a method for preparing 2, 3, 5-trichloropyridine on the basis of layered manganese oxide catalysts with nanometer zinc. The method includes steps of dissolving manganese nitrateand zinc acetate in water, uniformly mixing the manganese nitrate and the zinc acetate with each other to obtain first liquid, dropwise adding alkali liquor into the first liquid to obtain second liquid, stirring and precipitating the second liquid to obtain manganese/iron mixed precipitates, adding the manganese/iron mixed precipitates into potassium permanganate solution to obtain third liquid,oxidizing the third liquid, filtering and washing the third liquid, adding carbon powder into the third liquid to obtain mixtures and calcining the mixtures at the high temperatures to obtain the layered manganese oxide catalysts with the nanometer zinc; carrying out reaction on pentafluoropyridine, DMF (dimethyl formamide) and active potassium fluoride powder under the effects of the layered manganese oxide catalysts with the nanometer zinc under strong-alkali conditions, filtering reaction products, and adding filter cake into calcium fluoride solution to obtain the 2, 3, 5-trichloropyridine on the basis of the layered manganese oxide catalysts with the nanometer zinc. The pentafluoropyridine is used as a raw material, the DMF is used as a solvent, and the active potassium fluoride powder is used as fluorinating agent. The method for preparing the 2, 3, 5-trichloropyridine on the basis of the layered manganese oxide catalysts with the nanometer zinc has the advantages that the reaction is mild and is high in efficiency, and the 2, 3, 5-trichloropyridine which is a product prepared by the aid of the method is high in purity.
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Paragraph 0026; 0030; 0034; 0038; 0039; 0042; 0046; 0049
(2018/05/16)
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- Method for synthesizing 2, 3, 5-trichloropyridine
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The invention discloses a method for synthesizing 2, 3, 5-trichloropyridine. The method mainly comprises: (1) synthesis of 2, 3, 5-trichloro-6-hydrated hydrazinyl pyridine: adding hydrazine hydrate and a reaction solvent into 2, 3, 5, 6-tetrachloropyridine as a raw material, carrying out a reaction process at a certain temperature for some time and carrying out treatment to obtain 2, 3, 5-trichloro-6-hydrated hydrazinyl pyridine, and (2) reaction of 2, 3, 5-trichloro-6-hydrated hydrazinyl pyridine and a sodium hypochlorite aqueous solution in an alkaline environment at a certain temperature for a certain period of time, then treatment and reduced pressure distillation. The method has the advantages of low reaction raw material price, no high toxic, no irritation, small three waste amount,environmentally friendly processes, relatively thorough reaction, simple process control and high product yield.
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Paragraph 0039; 0040
(2019/01/07)
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- Preparation method of 2,3,5-trichloropyridine
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The invention discloses a preparation method of 2,3,5-trichloropyridine and aims to solve the problems that the production cost is high and a large quantity of sodium chlorate solutions are required to be consumed in existing patents. In the method, Water is taken as a solvent, sodium carbonate is taken as an acid-binding agent, butanol is taken as a catalysis aid, 2,3,4,5-tetrachloropyridine anda proper amount of hydrazine hydrate are subjected to a refluxing reaction at 90-95 DEG C, and trichloropyridine hydrazine is produced; trichloropyridine hydrazine is not separated and is directly oxidized by 30% hydrogen peroxide under the action of 5% sodium hydroxide and a phase transfer catalyst (the phase transfer catalyst can be benzyl triethyl ammonium chloride, beta-cyclodextrin and tetrabutylammonium bromide, preferably, benzyl triethyl ammonium chloride), and 2,3,5-trichloropyridine is obtained. 2,3,5-trichloropyridine is prepared with a one-pot method, the reaction procedure is concise, and industrialization is facilitated; besides, the water is taken as the solvent, hydrogen peroxide is taken as an oxidizing agent, the preparation process is green and environmentally friendly,the problems of consumption during recovery and excessive consumption of sodium chlorate are effectively solved, and the preparation method has remarkable progressive significance.
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Paragraph 0023; 0029-0040
(2018/09/08)
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- A wicked grass ether and intermediate 2, 3, 5 - trichloro-pyridine synthesis method (by machine translation)
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The invention discloses a wicked grass ether and intermediate 2, 3, 5 - trichloro-pyridine synthesis method, in particular comprising the following steps: 1st step, pyridine (I) with chlorine in the chlorination reaction under the presence of a base catalyst, through a chlorination reaction, synthesis of chloro-pyridine (II); 2nd step, multi-chloro-pyridine (II) is mixed with hydrogen, by dechlorination reaction catalyst to catalyze the hydrogenation, by hydrogenation dechlorination reaction, by 2, 3, 5 - trichloropyridine (III), the hydrogenation dechlorination reaction catalyst is platinum, palladium, a ruthenium carbon; 3rd step, 2, 3, 5 - trichloropyridine (III) with the N - [( ±) - 2 - (4 - hydroxy benzene ammonia oxygen) propionyl] Isoxazolidine (IV), acid, organic solvent are mixed to obtain a wicked grass ether (V). The advantage of this invention is characterized in that: the main raw material sources are extensive, the product quality is high, high yield, waste water is less, large-scale production of 2, 3, 5 - dichloro pyridine, 2, 3 - chlorinate and downstream various pesticide production and model chloro pyridine pesticide development provides a convenient method of cleaning low energy consumption. (by machine translation)
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Paragraph 0032; 0033; 0034; 0037; 0038 0039; 0040; 0041; 004
(2017/07/19)
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- Preparation method of 2, 3, 5-trichloropyridine
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The invention discloses a preparation method of 2, 3, 5-trichloropyridine. The preparation method comprises the following steps: 1, dissolving sodium trichloropyrindinol into a sodium hydroxide solution, and conducting hydrodechlorination through a hydrogenation catalyst; 2, acidizing a mixture obtained in step 1, and conducting crystallization and filtration, so that 3,5-dichloropyrindinol is obtained; 3, making the 3,5-dichloropyrindinol obtained in step 2 react with a chlorinating agent. According to the preparation method of the 2, 3, 5-trichloropyridine, 3,5- sodium dichloropyrindinol is prepared by conducting catalytic hydrogenation on the sodium trichloropyrindinol, then the 2, 3, 5-trichloropyridine is prepared, synthesis cost is low, and the yield is high; hydrodechlorination is conducted on the 2, 3, 5- sodium trichloropyrindinol directly through the hydrogenation catalyst, the problem that a great amount of waste water is generated in the tetrachloropyridine and pentachloropyridine zinc powder reduction process is avoided, and harm caused to the environment is lowered; the pressure of hydrogen ranges from 0.1 Mpa to 3 Mpa, and the requirement for equipment is low; a great amount of heat is not generated in the reaction process, and the reaction temperature is easy to control.
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Paragraph 0027; 0028; 0029; 0033; 0034
(2016/11/14)
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- A 2,3-chloro-5-chlorotrifluoromethylbenzene methylpyridinio synthetic method (by machine translation)
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The invention relates to a 2,3 the [...] -5 the method for synthesizing methylpyridinio [...], which belongs to the field of chemical synthesis. Traditional production 2, the 3 [...] -5 the backward [...] methylpyridinio process, flow is long, the yield is low, a large amount of the three wastes, it is difficult to control. The present invention provides a mild reaction conditions, the high yield of 2,3 the [...] -5 the method for synthesizing methylpyridinio [...]. (by machine translation)
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Paragraph 0007
(2016/11/02)
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- Chiral Hexahalogenated 4,4′-Bipyridines
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The preparation of 27 isomers of chiral hexahalogeno-4,4′-bipyridines by means of two complementary methods is described. The first one is convergent and based on the LDA-induced 4,4′-dimerization of trihalopyridines, whereas the second method is divergent and achieved through regioselective halogenation reactions of 4,4′-bipyridine-2,2′-diones. Iodine in 2,2′-positions of the 4,4′-bipyridines was introduced by a copper-catalyzed Finkelstein reaction (Buchwald procedure) performed on 2,2′-dibromo derivatives. Selected compounds of this new family of atropisomeric 4,4′-bipyridines were enantioseparated by high performance liquid chromatography on chiral stationary phases, and the absolute configurations of the separated enantiomers were assigned by using X-ray diffraction analysis. The latter revealed that various halogen bond types are responsible for crystal cohesion.
- Mamane,Peluso,Aubert,Cossu,Pale
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p. 4576 - 4587
(2016/07/06)
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- Chemical process
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A process for the preparation of 3,5-dichloropyridine comprising reacting a trichloropyridine, a tetrachloropyridine or pentachloropyridine with zinc metal, in the presence of an acidic compound and at a temperature in the range 50-120° C.
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Page/Page column 3
(2008/06/13)
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- Process for preparing (poly)chloropyridines
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The object of the present invention is to provide a process for preparing pyridine chloride in a high yield at a low cost. As a starting material one uses clorohydrazinopyridine represented by the formula wherein X1to X5are the same or different and represent a chlorine atom, a hydrogen atom or a hydrazino group (-NHNH2), provided that at least one of X1to X5represents a chlorine atom and at least one of X1to X5represents a hydrazino group. This chlorohydrazinopyridine is oxidized with hydrogen peroxide in the presence of a phase transfer catalyst in a mixture of an organic solvent and water.
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- Process for preparing pyridine chloride
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An improved method of preparing a pyridine chloride from a chlorohydrazinopyridine is disclosed.
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- Phenoxyphenyl phosphinates
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Novel phenoxy-, phenylthio, anilino-, benzyl-, pyridyloxy-, pyridylthio-, pyridylamino-, or pyridylmethyl-phenyl substituted phosphinates and phosphinothioates, synthesis thereof, intermediates therefore, and the use of said novel compounds for the control of weeds.
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- CONVENIENT APPROACHES TO HETEROCYCLES VIA COPPER-CATALYSED ADDITIONS OF ORGANIC POLYHALIDES TO ACTIVATED OLEFINS
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An efficient method for the synthesis of 2,3-dichloro-5-substituted (Cl, CF3, alkyl) pyridines 29 starting from the 1:1 adducts of the copper-catalysed addition of chloral or the corresponding 2,2-dichloroaldehydes to acrylonitrile is presented.Proper choice of experimental conditions allows the preparation of 29 in one-pot process.Similarly, the CuCl-catalysed reaction of methyl itaconate with several trichloromethyl compounds R-CCl3 gives 6-R-substituted 2-pyrone derivatives 40 via dehalogenation and subsequent thermal ring closure of the primary 1:1-adducts. The new electrophilic 2-pyrone 40b undergoes-cycloaddition reactions with inverse electron demand with a number of olefins and acetylenes, allowing thereby regioselective transfer of a trifluoromethyl group from a simple Freon derivative (1,1,1-trichloro-2,2,2-trifluoroethane) into more complex organic molecules.Finally, the 1:1-adduct of trichloroacetylchloride with methyl acrylate allows a very covenient synthesis of novel N-substituted derivatives 66 of pyroglutamic acid as well as of proline.
- Martin, Pierre,Steiner, Eginhard,Streith, Jacques,Winkler, Tammo,Bellus, Daniel
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p. 4057 - 4078
(2007/10/02)
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- DESTRUCTIVE CHLORINATION OF 3,4,5-TRICHLORO-2-(TRICHLOROMETHYL)PYRIDINE
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The extensive destructive chlorination of 3,4,5-trichloro-2-(trichloromethyl)pyridine proceeds by both thermal (160-245 deg C) and photochemical pathways.Perchloropyridine, perchloropicoline, and carbon tetrachloride are formed.The chlorinated derivatives of pyridine are formed by the loss of the CCl3 group with its subsequent replacement by a chlorine atom.
- Emel'yanov, V. I.,Stul', B. Ya.,Korolev, B. M.
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p. 1168 - 1171
(2007/10/02)
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- Process for producing 2,3,5-trichloropyridine, 2,4,4-trichloro-4-formyl-butyronitrile as a novel compound and a process for producing it
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A novel process for producing 2,3,5-trichloropyridine is described. The process comprises the addition reaction of trichloroacetaldehyde with acrylonitrile in the presence of a catalyst, and the subsequent cyclization of the intermediately formed 2,4,4-trichloro-4-formylbutyronitrile, with the splitting-off of water, to give 2,3,5-trichloropyridine.2,4,4-Trichloro-4-formylbutyronitrile occurring as an intermediate product in the process according to the invention is a novel compound. It can be produced by the addition reaction of trichloroacetaldehyde with acrylonitrile in the presence of a catalyst.2,3,5-Trichloropyridine can be used as intermediate for the production of herbicidal active substances.
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- The Specificity of Reductive Dechlorination in the Polychloropyridine Series. Synthesis of 2,3,5-Trichloro- and 2,3,5,6-Tetrachloropyridine
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The high specificity of the reduction system zinc and ammonium salts in dimethyl methylphosphonate as solvent is demonstrated in several reductive dechlorination reactions of polychloropyridines.The reduction of pentachloropyridine with zinc/ammonium chloride system in dimethyl methylphosphonate yielded solely 2,3,5,6-tetrachloropyridine.Similarly, the reduction of 2,3,4,5-tetrachloropyridine with zinc and tetramethylammonium salt of methyl methylphosphonate furnished exclusively 2,3,5-trichloropyridine.A synthetic procedure for the preparation of the new ammonium salts of methyl methylphosphonate is given.
- Sutter, P.,Weis, C. D.
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p. 493 - 496
(2007/10/02)
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- Preparation of 2,3,5-trichloropyridine
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2,3,5-Trichloropyridine is prepared by the direct reaction of pentachloropyridine or 2,3,5,6-tetrachloropyridine with metallic zinc in the presence of a strongly alkaline aqueous solution and a water-immiscible reaction medium.
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- Preparation of chloro substituted pyridines
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In the process for preparing 2,3,5-trichloropyridine, 2,3,4,5- or 2,3,5,6-tetrachloropyridine by the oxidation of the appropriate trichloro- or tetrachlorohydrazinopyridine, the improvement which comprises carrying out the oxidation with an alkaline hypochlorite in the presence of a reaction medium.
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