- PROCESS FOR PREPARATION OF 2,4,6-TRIFLUOROBENZOIC ACID
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The present invention provides a process for the preparation of 2,4,6-trifluorobenzoic acid, having less than 0.05% of 2,6-difluorobenzoic acid and/or 2,4-difluorobenzoic acid impurities. The 2,4,6-trifluorobenzoic acid is crucial and an important raw material for preparing the photosensitizers, medicines and pesticides, and also finds applications in pharmaceutical and agrochemical industries.
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Page/Page column 10; 11
(2021/08/14)
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- Preparation method of compound 2,4,6-trifluorobenzylamine
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The invention discloses a preparation method of a compound 2,4,6-trifluorobenzylamine, and relates to the field of organic synthesis. According to the preparation method, pentachlorobenzonitrile is used as a starting raw material and is subjected to a fluorination reaction with a fluorinating agent in an organic solvent under the action of a catalyst to obtain 3,5-dichloro-2,4,6-trifluorobenzonitrile. The obtained 3,5-dichloro-2,4,6-trifluorobenzonitrile is added into water and reacts with zinc powder and mixed acid, and then reflux dechlorination is performed to obtain 2,4,6-trifluorobenzonitrile. The obtained 2,4,6-trifluorobenzonitrile is added into an organic solvent, and hydrogenation reduction is carried out under the action of an organic alkali and a catalyst to obtain the product 2,4,6-trifluorobenzylamine. The method has the advantages of short synthesis route, simple operation, mild reaction conditions, cheap and easily available raw materials and stable product quality, andis suitable for large-scale industrial production.
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Paragraph 0024; 0033-0052
(2021/03/11)
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- Mechanistic Insights into C(sp2)?C(sp)N Reductive Elimination from Gold(III) Cyanide Complexes
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A new family of phosphine-ligated dicyanoarylgold(III) complexes has been prepared and their reactivity towards reductive elimination has been studied in detail. Both, a highly positive entropy of activation and a primary 12/13C KIE suggest a late concerted transition state while Hammett analysis and DFT calculations indicate that the process is asynchronous. As a result, a distinct mechanism involving an asynchronous concerted reductive elimination for the overall C(sp2)?C(sp)N bond forming reaction is characterized herein, for the first time, complementing previous studies reported for C(sp3)?C(sp3), C(sp2)?C(sp2), and C(sp3)?C(sp2) bond formation processes taking place on gold(III) species.
- Genoux, Alexandre,González, Jorge A.,Merino, Estíbaliz,Nevado, Cristina
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p. 17881 - 17886
(2020/08/19)
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- PROCESS FOR PREPARATION OF HALOGENATED BENZYLAMINE AND INTERMEDIATES THEROF
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The present invention provides an improved process for the preparation of halogenated benzylamine having the formula I from halogenated benzonitriles, Formula I wherein, X1 is selected from group consisting of hydrogen, chloro or fluoro, provided atleast one X1 is chloro or fluoro.
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Page/Page column 13
(2020/08/13)
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- Preparation method of 2,4,6-trifluorobenzylamine
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The invention provides a preparation method of 2,4,6-trifluorobenzylamine. The preparation method comprises the following steps: S1, by taking pentachloro benzonitrile as a starting material, adding the pentachloro benzonitrile into anhydrous potassium fluoride for fluorination reaction in a first organic solvent, thus obtaining 3,5-dichloro-2,4,6-trifluoro-cyanophenyl; S2a, adding the 3,5-dichloro-2,4,6-trifluoro-cyanophenyl prepared in the step S1 into a second organic solvent, adding organic alkali, feeding hydrogen, and carrying out dehydrochlorination reaction under the action of a firstcatalyst, thus obtaining 2,4,6-trifluoro-cyanophenyl serving as an intermediate; S3, adding the 2,4,6-trifluoro-cyanophenyl prepared in the step S2a into a third organic solvent, adding acid, feedinghydrogen, and reducing the 2,4,6-trifluoro-cyanophenyl serving as the intermediate through a cyanogroup under the action of a second catalyst, thus obtaining 2,4,6-trifluorobenzylamine. By the adoption of the technical scheme, the preparation method has the advantages that steps of a synthesis route are simple and short, conditions are mild, operation is simple and convenient, the raw materials are low in cost and readily available, and the production cost is low; the catalysts and solvents can be recycled for use, so that pollution is reduced; the preparation method is environmentally friendly and suitable for industrial large-scale production.
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Paragraph 0051; 0052; 0056; 0072; 0074; 0076
(2018/03/24)
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- Preparation method of 2,4,6-trifluorobenzylamine
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The invention discloses a preparation method of 2,4,6-trifluorobenzylamine, and belongs to the technical field of chemical synthesis. The method comprises the following steps: (1), carrying out fluorination reaction on pentachloro benzonitrile and a fluorinating agent in a polar aprotic solvent at the presence of a catalyst so as to obtain 2,4,6-trifluoro-3,5-dichlorobenzonitrile; (2), carrying out hydrogen hydrogenation reduction on 2,4,6-trifluoro-3,5-dichlorobenzonitrile obtained in the step (1) by using palladium charcoal as a catalyst at the presence of organic carboxylic acid so as to obtain 2,4,6-trifluoro-3,5-dichlorobenzylamine; (3) carrying out hydrogen hydrogenation reduction on 2,4,6-trifluoro-3,5-dichlorobenzylamine obtained in the step (2) in the solvent under an effect of the catalyst so as to obtain 2,4,6-trifluorobenzylamine. The preparation method has the advantages of low costs of the raw materials, short reaction steps, high reaction yield, high purity of products and the like, and is suitable for industrial production and application.
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Paragraph 0096-0101
(2018/10/11)
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- Aromatic radical-anions. XII. A cyclic amperometric and ESR study of the transformations of polyfluorinated benzonitrile radical-anions
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Cyclic voltamperometry and ESR spectrometry were used to study the chemical transformations of radical-anions of benzonitrile derivatives containing from two to five fluorine atoms.Two types of transformations were found to be characteristic for such species, namely, the elimination of a fluoride anion and subsequent formation of defluorination products and dimerization with the subsequent formation of fluorinated derivatives of 4,4'-dicyanodiphenyl.The facility of these processes depends significantly on the number and arrangement of the fluorine atoms in the benzene ring.The relationship between the electronic structure and reactivity of fluorinated benzonitrile radical-anions was examined.
- Efremova, N. V.,Starichenko, V. F.,Shteingarts, V. D.
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