52334-81-3Relevant articles and documents
METHOD FOR PREPARING 2,3-DICHLORO-5-TRIFLUOROMETHYLPYRIDINE WITH HIGH SELECTIVITY
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Paragraph 0179-0216, (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.
Catalyst-Free N-Deoxygenation by Photoexcitation of Hantzsch Ester
Cardinale, Luana,Jacobi Von Wangelin, Axel,Konev, Mikhail O.
supporting information, (2020/02/15)
A mild and operationally simple protocol for the deoxygenation of a variety of heteroaryl N-oxides and nitroarenes has been developed. A mixture of substrate and Hantzsch ester is proposed to result in an electron donor-acceptor complex, which upon blue-light irradiation undergoes photoinduced electron transfer between the two reactants to afford the products. N-oxide deoxygenation is demonstrated with 22 examples of functionally diverse substrates, and the chemoselective reduction of nitroarenes to the corresponding hydroxylamines is also shown.
METHOD FOR SEPARATING AND PURIFYING 2-CHLORO-3-TRIFLUOROMETHYLPYRIDINE
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Paragraph 0092-0095, (2020/02/27)
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.
Production method of high-purity 2-chloro-5-trifluoromethylpyridine
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Paragraph 0028-0029, (2018/03/23)
The invention provides a production method of high-purity 2-chloro-5-trifluoromethylpyridine. The production method comprises the following steps: under the action of a silicon dioxide-aluminum oxide-chromic oxide catalyst, gasifying the raw materials acrolein and propyl aldehyde, and reacting with an ammonia gas to generate 3-methylpyridine; gasifying the 3-methylpyridine and carbon tetrachloridetogether, reacting in a chlorine atmosphere to obtain 2-chloro-5-trichloromethylpyridine, and performing fluoro-substitution to obtain a crude product of 2-chloro-5-trifluoromethylpyridine; heating to melt the crude product of 2-chloro-5-trifluoromethylpyridine; refrigerating and circulating in a low-temperature thermostat; cooling and crystallizing and separating to obtain recrystal; sweating the recrystal; repeating the processes of circulating, melting, recrystallizing and sweating to obtain high-purity 2-chloro-5-trifluoromethylpyridine. According to the production method provided by theinvention, 3-methylpyridine is adopted as a raw material, and the 2-chloro-5-trifluoromethylpyridine is molten, recrystallized and purified so that the product has high purity and stable yield.
Preparation method of 2-cholrine-5-trifluoromethyl pyridine
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Paragraph 0025; 0026; 0030-0033, (2017/05/13)
The invention discloses a preparation method of 2-cholrine-5-trifluoromethyl pyridine. The method comprises the following steps of 1, adding a raw material 2-cholrine-5-methyl fluoride pyridine into a reaction kettle, and then adding thionyl chloride; 2, raising the temperature, and introducing chlorine into the reaction kettle; 3, after introduction of chlorine is ended, transferring the raw material into a fluorination kettle; 4, adding hydrogen fluoride which is measured well into the fluorination kettle, adding anhydrous hydrogen fluoride, raising the temperature, and conducting a reaction; 5, conducing washing and water vapor distillation on a fluoridation material, adjusting the pH value, and conducting distillation in a pressing-in rectifying tower, so that 2-cholrine-5-trifluoromethyl pyridine is obtained. According to the preparation method, thionyl chloride is adopted as solvent, so that the problem that the material contains water is solved; meanwhile, low-temperature chlorination is adopted for producing the 2-cholrine-5-trifluoromethyl pyridine chlorination material, and the foundation is laid for preparing high-purity 2-cholrine-5-trifluoromethyl pyridine.
Copper-catalysed synthesis of trifluoromethyl(hetero)arenes from di(hetero)aryl-λ3-iodanes
Pandey, Vinay Kumar,Anbarasan, Pazhamalai
, p. 18525 - 18529 (2016/02/27)
An efficient synthesis of trifluoromethylated (hetero)arenes has been achieved through the regioselective copper-catalyzed trifluoromethylation of di(hetero)aryl-λ3-iodanes, employing readily available trifluoromethyltrimethylsilane. The reaction works well for both symmetrical and unsymmetrical di(hetero)aryl-λ3-iodanes with good regioselectivity and also tolerates diverse functional groups such as bromo, iodo, cyano, nitro, ester, ketone and enolizable ketone.
TCDA: Practical Synthesis and Application in the Trifluoromethylation of Arenes and Heteroarenes
Wang, Jian,Zhang, Xiaomin,Wan, Zehong,Ren, Feng
, p. 836 - 839 (2016/05/19)
A practical synthesis of the reagent trimethylsilyl chlorodifluoroacetate (TCDA) is reported on 50 g scale. The trifluoromethylation with TCDA was optimized, and the reaction shows very broad scope with respect to electron-deficient, -neutral, -rich aryl/heteroaryl iodides, as well as excellent functional group tolerability, such as ester, amide, aldehyde, hydroxyl, and carboxylic acid. The reagent was also applied to the late-stage trifluoromethylation of three medicinally relevant compounds. Additionally, the building block trifluoromethylpyridine and one drug related molecule Boc-Fluoxetin were synthesized in 10 g scale by this method, demonstrating its practical applications in process chemistry.
New Reagent for Highly Efficient Synthesis of Trifluoromethyl-Substituted Arenes and Heteroarenes
Zhang, Xiaomin,Wang, Jian,Wan, Zehong
supporting information, p. 2086 - 2089 (2015/05/13)
A new reagent trimethylsilyl chlorodifluoroacetate (TCDA) is reported for the introduction of a -CF3 group to arenes and heteroarenes. Compared with current known reagents, TCDA shows very broad scope with respect to electron-deficient, -neutral, and -rich aryl/heteroaryl iodides as well as excellent functional group tolerance, including ester, amide, aldehyde, hydroxyl, and carboxylic acid. (Chemical Equation Presented).
Catalytic trifluoromethylation of aryl- and vinylboronic acids by 2-cyclopropyl-1-(trifluoromethyl)benzo[ b ]thiophenium triflate
Arimori, Sadayuki,Shibata, Norio
supporting information, p. 1632 - 1635 (2015/04/14)
Catalytic trifluoromethylation of aryl- and vinylboronic acids by 2-cyclopropyl-1-(trifluoromethyl)benzo[b]thiophenium triflate is described. In the presence of a catalytic amount of CuOAc and 2,4,6-collidine in ethyl acetate, the reaction proceeded in good to high yields for various substrates under mild reaction conditions at room temperature.
Practical method for the Cu-mediated trifluoromethylation of arylboronic acids with CF3 radicals derived from NaSO2CF3 and tert-butyl hydroperoxide (TBHP)
Ye, Yingda,Kuenzi, Stefan A.,Sanford, Melanie S.
supporting information, p. 4979 - 4981,3 (2012/12/12)
A mild and practical protocol for the copper-mediated trifluoromethylation of aryl and heteroaryl boronic acids using NaSO2CF3 (Langlois' reagent) and TBHP is described. The reaction proceeds at room temperature under ambient conditions, and the products can be readily purified by extraction or column chromatography.
