- Anion ligand promoted selective C-F bond reductive elimination enables C(sp2)-H fluorination
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A detailed mechanism study on the anion ligand promoted selective C-H bond fluorination is reported. The role of the anion ligand has been clarified by experimental evidence and DFT calculations. Moreover, the nitrate promoted C-F bond reductive elimination enabled a selective C-H bond fluorination of various symmetric and asymmetric azobenzenes to access diverse o-fluoroanilines.
- Mao, Yang-Jie,Luo, Gen,Hao, Hong-Yan,Xu, Zhen-Yuan,Lou, Shao-Jie,Xu, Dan-Qian
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supporting information
p. 14458 - 14461
(2019/12/09)
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- Synthesis of 2 - fluoro aniline compounds of the method
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The invention discloses a method for synthesizing 2 - fluoro aniline compounds of the method, the method is: shown in formula Ia aniline compound of formula Ib α and β shown aniline compound as raw materials, through coupling reaction shown [...] azobenzene compound II, then the type II shown azobenzene compound with a palladium catalyst, fluorination reagent, additive, organic solvent, in the 30 - 150 °C temperature closed agitating the fluorination reaction, [...] compound of formula III, type III compounds are shown in the reaction under the action of a reducing [...] shown IV 2 - fluoro aniline compounds; this invention synthetic 2 - fluoro aniline compounds substrate wide adaptability, mild reaction conditions, the operation is simple, fluorinated and good selectivity, [...] aniline compounds is prepared by many drug molecule is an important intermediate and starting material, wide application prospects.
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- A aqueous phase preparation 2, 6 - [...] method
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The invention relates to a green preparation 2, 6 - [...] synthetic method, to industrial product is 2, 6 - difluoro-benzamide as the starting material, passes through the aqueous phase Huffman degradation reaction, the aqueous phase diazotisations directly after the hydrolysis, direct concentrated nitric acid nitration, the iron powder reduces the aqueous phase, the aqueous phase with the aqueous phase to diazotization coupling reaction of phenol, after five step process for preparing aqueous phase reactions 2, 6 - [...] production process and corresponding various process conditions. The beneficial effect of the present invention is: select industrialized product 2, 6 - difluoro-benzamide as the raw material, raw materials are easy, low cost, through the aqueous phase reaction and solvent-free reaction for the preparation of 2, 6 - [...], its mild reaction conditions and environmental, safety and high efficiency. The present invention provides a kind of environmental protection, model, high efficiency can be used for the industrial production of 2, 6 - [...] green synthetic pathway.
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Paragraph 0010; 0013; 0017-0023
(2019/03/28)
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- Method for preparing 2,6-difluoroindophenol acetate
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The invention relates to a novel synthetic method for preparing 2,6-difluoroindophenol acetate, in particular to a production process for preparing the 2,6-difluoroindophenol acetate successively by virtue of six reaction steps of industrialized product 2,6-difluorobenzamide serving as a raw material, i.e. Hofmann degradation reaction, diazotization and direct hydrolysis, nitrification with concentrated nitric acid, catalytic hydrogenation reduction with palladium on carbon, diazotization and phenol coupling reaction and esterification under the condition of acetic anhydride and various corresponding process conditions. The method has the beneficial effects that the industrialized product 2,6-difluorobenzamide is used as the raw material, the raw material is easy to obtain, the price is low, and the reaction condition is mild and environmentally friendly. The invention provides a novel efficient way for producing the 2,6-difluoroindophenol acetate in an industrialization manner.
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Paragraph 0014
(2019/03/28)
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- AROMATIC FLUORINE CHEMISTRY. PART 5. PREPARATION OF 2,6-DIFLUOROANILINE AND 1,2-DIFLUOROBENZENE
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The preparation of 2,6-difluoroaniline and 1,2-difluorobenzene from 1,2,3-trichlorobenzene is described.An isomeric mixture of 1-chloro-2,3-difluorobenzene and 2-chloro-1,3-difluorobenzene is obtained from KF exchange on 1,2,3-trichlorobenzene.Selective dechlorination of 1-chloro-2,3-difluorobenzene with H2 and Pd/C catalyst gives 1,2-difluorobenzene. 2,6-difluoroaniline is obtained via ammonolysis of 2-chloro-1,3-difluorobenzene.
- Pews, R. Garth,Gall, James A.
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p. 379 - 386
(2007/10/02)
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- Process for the preparation of 5-amino-3-chlorosulfonyl-1,2,4-triazole
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5-Amino-3-chlorosulfonyl-1,2,4-triazole is prepared by the chlor-oxidation of 5-amino-3-mercapto-1,2,4-triazole. The process is characterized by the preformation of disulfide from the mercaptan prior to treatment with chlorine. The 5-amino-3-chlorosulfonyl-1,2,4-triazole reaction mixture can be directly reacted with substituted anilines to prepare N-(3-(((aryl)amino)sulfonyl)-1H-1,2,4-triazol-5-yl)amines which are useful intermediates for the manufacture of herbicides.
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- AROMATIC FLUORINE CHEMISTRY. PART 4. PREPARATION OF 2,6-DIFLUOROANILINE
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The preparation of 2,6-difluoroaniline from 1,3,5-trichlorobenzene is described. 1-Chloro-3,5-difluorobenzene prepared via KF exchange on 1,3,5-trichlorobenzene is dichlorinated and nitrated in a single reactor to a mixture of trichlorodifluoronitrobenzenes.The latter are reduced to ca. 4:1 mixture of 2,6-difluoroaniline and 2,4-difluoroaniline.
- Pews, R. G.,Gall, J. A.
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p. 307 - 316
(2007/10/02)
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- Process and intermediates for the preparation of 2,6-difluoroaniline
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1-Chloro-3,5-difluorobenzene is chlorinated to give 4,6-difluoro-1,2,3-trichlorobenzene which in turn is nitrated and reduced to the corresponding novel aniline, 2,6-difluoro-3,4,5-trichloroaniline. Further reduction of this aniline provides 2,6-difluoroaniline with high selectivity.
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