- Preparation method of 2-chloro-3-trifluoromethylpyridine
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The invention discloses a preparation method of 2-chlorine- 3-trifluoromethylpyridine. The method comprises the following steps: (1), sequentially adding 2, 3, 6-trichloro-5-trifluoromethylpyridine, an acid-binding agent and a catalyst into a lower aliphatic alcohol solvent, and starting a circulating water pump to replace hydrogen in vacuum, with the addition amount of the catalyst being 0.01-0.5% of the reaction system; (2), controlling the temperature of the reductive dechlorination reaction to be -10-65 DEG C, the reaction hydrogen pressure to be 0.1-2.0 MPa and the reaction time to be 4-24 hours; and (3), filtering, rectifying and purifying the obtained reaction liquid in sequence to finish separation of corresponding products and unreacted raw materials. The preparation method of the2-chlorine-3-trifluoromethylpyridine, provided by the invention is simple in process, easy to operate and beneficial to industrial production, the obtained product is high in purity, the purity is greater than 98%, a plurality of useful products are produced at one time, and on the basis of the selectivity of the useful products, the selectivity is 95%, the conversion rate of a single raw material is over 95%, and the production cost is low.
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Paragraph 0029-0061
(2021/01/25)
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- METHOD FOR SEPARATING AND PURIFYING 2-CHLORO-3-TRIFLUOROMETHYLPYRIDINE
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A method for separating and purifying 2-chloro-3-trifluoromethylpyridine useful as an intermediate for medicines, agrochemicals, and the like is provided. The method includes: 1) in the process of producing chloro β-trifluoromethylpyridine compounds by allowing a β-methylpyridine compound to react with chlorine and hydrogen fluoride in a reaction apparatus, allowing a β-trifluoromethylpyridine compound to react with chlorine in a reaction apparatus, or allowing a chloro β-trichloromethylpyridine compound to react with hydrogen fluoride in a reaction apparatus,2) fractionating a liquid mixture containing chloro β-trifluoromethylpyridine compounds from the reaction apparatus, and3) separating and purifying 2-chloro-3-trifluoromethylpyridine from the liquid mixture.
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Paragraph 0100-0105
(2020/02/27)
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- Preparation method of non-transition metal-catalyzed 2-halogenated pyridine compound
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The invention provides a preparation method of a non-transition metal-catalyzed 2-halogenated pyridine compound. The 2-halogenated pyridine compound is an important component of many medicines and bioactive molecules and has important application in the fields of organic synthesis, medicinal chemistry and the like and wide market prospects. The invention relates to the preparation method of the non-transition metal-catalyzed 2-halogenated pyridine compound. According to the method, pyridine-2-carboxylic acid, derivatives of the pyridine-2-carboxylic acid, NaF, KF, CsF, TBAF, NaCl, KCl, CsCl, TBAC, NCS, NaBr, KBr, CsBr, Br2, TBAB, NBS, NaI, KI, CsI, I2 and NIS are used as raw materials, and under the presence of base and an accelerant and mild conditions, the 2-halogenated pyridine compoundis synthesized. The method has the advantages that the steps are simple, the raw materials are easy to obtain, the reaction conditions are mild and the like; the method has great use value and socialand economic benefits.
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Paragraph 0056-0058
(2018/10/11)
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- Trifluoromethylation of (hetero)aryl iodides and bromides with copper(i) chlorodifluoroacetate complexes
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A new copper-mediated trifluoromethylation reaction using copper(i) chlorodifluoroacetate complexes as reagents is reported. The complex [L2Cu][O2CCF2Cl] (L = bpy, dmbpy, phen) reacted with (hetero)aryl iodides and bromides in the presence of CsF in DMF at 75 °C to afford the trifluoromethylarenes in good to excellent yields. High compatibility with various chemical functions or (hetero)cycles was also observed in the reaction. A reaction mechanism involving a difluorocarbene intermediate, along with a subsequent formation of a -CF3 anion was proposed.
- Lin, Xiaoxi,Li, Zhengyu,Han, Xiaoyan,Weng, Zhiqiang
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p. 75465 - 75469
(2016/08/24)
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- Copper-mediated perfluoroalkylation of heteroaryl bromides with (phen)CuRF
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The attachment of perfluoroalkyl groups onto organic compounds has been a major synthetic goal over the past several decades. Previously, our group reported phenanthroline-ligated perfluoroalkyl copper reagents, (phen)CuR F, which react with aryl iodides and aryl boronates to form the corresponding benzotrifluorides. Herein the perfluoroalkylation of a series of heteroaryl bromides with (phen)CuCF3 and (phen)CuCF 2CF3 is reported. The mild reaction conditions allow the process to tolerate many common functional groups. Perfluoroethylation with (phen)CuCF2CF3 occurs in somewhat higher yields than trifluoromethylation with (phen)CuCF3, creating a method to generate fluoroalkyl heteroarenes that are less accessible from trifluoroacetic acid derivatives.
- Mormino, Michael G.,Fier, Patrick S.,Hartwig, John F.
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p. 1744 - 1747
(2014/04/17)
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- PROCESSES FOR PRODUCING 2-CHLORO-3-TRIFLUOROMETHYLPYRIDINE
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The present invention provides processes for producing 2-chloro-3-trifluoromethylpyridine which is useful as an intermediate for medicines and agrochemicals, at a high production rate in a high yield. Specifically, the present invention relates to a process for producing 2-chloro-3-trifluoromethylpyridine or a salt thereof comprising allowing 3-trifluoromethylpyridine N-oxide to react with a chlorinating agent; and also relates to a process for producing 2-chloro-3-trifluoromethylpyridine or a salt thereof comprising oxidizing 3-trifluoromethylpyridine to produce 3-trifluoromethylpyridine N-oxide and subsequently allowing the obtained 3-trifluoromethylpyridine N-oxide to react with a chlorinating agent.
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Page/Page column 3
(2012/10/18)
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- Trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper
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A literature method reported for iodobenzene and congeners was successfully extended to the pyridine series. 2-Iodopyridines can be converted into 2-(trifluoromethyl)pyridines almost quantitatively. In contrast, yields are moderate at best if 3- and 4-iodopyridines or 2-bromopyridines are used as the starting materials. WILEY-VCH Verlag GmbH 2002.
- Cottet, Fabrice,Schlosser, Manfred
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p. 327 - 330
(2007/10/03)
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