1073-06-9Relevant articles and documents
A green environmental protection of the bromobenzene [...] preparation method (by machine translation)
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Paragraph 0025-0056, (2018/11/26)
The present invention provides a green environmental protection of the bromobenzene [...] preparation method, comprises the following steps: sulfuric acid and [...] aniline added in a reaction kettle, stirring cooling to 5 - 10 °C, thermal insulation and slowly instillment bromide, dropping after the completion of the slow heating to 15 - 20 °C, thermal insulation and dropping hydrogen peroxide solution, the constant temperature reaction, again lowering the temperature to 0 - 5 °C, thermal insulation and dropping nitroso sulfuric acid, thermal insulation reaction, slow heating to 35 - 40 °C, thermal insulation and dropping isopropyl alcohol and water mixture, after dropping the stirring, heating up to 55 - 60 °C, thermal insulation, layered, separation [...] and oil reservoir; the oil reservoir is arranged in the rectification apparatus, first heating up to 65 - 70 °C, after the heat preservation, heating up to 83 - 85 °C, distillation separation, to obtain [...] bromobenzene and 3, 5 - dibromide fluoride; the water through distillation, obtained from the isopropyl alcohol, a mixture of water and acetone and sulfuric acid, the isopropanol, water and the mixture for catalytic hydrogenation, to obtain the isopropanol-water solution. (by machine translation)
Preparation method of 3-bromofluorobenzene
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Paragraph 0069; 0070; 0071; 0072; 0073; 0074; 0075-0081, (2018/05/16)
The invention relates to the field of organic synthesis and in particular relates to a preparation method of 3-bromofluorobenzene. The preparation method of the 3-bromofluorobenzene, provided by the invention, comprises the following steps: 1) enabling o-fluoroaniline to react with sulfuric acid and a bromination reagent to prepare 2-fluoro-4-bromoaniline sulfate; 2) enabling the 2-fluoro-4-bromoaniline sulfate to react with sodium nitrite in the presence of a reducing agent and a catalyst under an acidic condition, so as to prepare the 3-bromofluorobenzene. The preparation method of the 3-bromofluorobenzene, provided by the invention, has the advantages of cheap and easy-to-obtain raw materials, simple technology, feasibility in post-treatment and high yield and is extremely applicable toindustrialization; acid water produced by diazo deamination reaction can be used repeatedly; after the acid water is repeatedly used for a plurality of times, enriched low-boiling-point solvents including isopropyl alcohol, acetone and the like in the acid water can be removed by distillation and then the acid water can be continually used repeatedly; in a diazo deamination process, hypophosphorous acid in a traditional technology is replaced with low-grade alcohol, so that water eutrophication caused by the fact that the phosphorus content in water exceeds the standard is avoided.
An intramolecular: Ortho -assisted activation of the silicon-hydrogen bond in arylsilanes: An experimental and theoretical study
Durka, Krzysztof,Urban, Mateusz,Czub, Maja,D?browski, Marek,Tomaszewski, Patryk,Luliński, Sergiusz
, p. 3705 - 3716 (2018/03/21)
An intramolecular activation of the Si-H bond in arylsilanes by selected ortho-assisting functional groups based on boron, carbon and phosphorus was investigated experimentally and by means of theoretical calculations. The major conclusion drawn is that the presence of a negatively charged oxygen atom in the functional group is essential for providing effective chelation to the silicon atom which in turn results in the increased hydridic character of a resulting five-coordinated species. In contrast, an intermolecular attack of hydroxide on the silicon atom in aryldimethylsilane results in the activation of the silicon-aryl bond. This increased reactivity of the Si-H bond in intramolecularly coordinated arylsilanes can be ascribed to a significant trans effect which operates in the preferred configuration. Hydrolytic cleavage of the Si-H bond results in dihydrogen elimination and the formation of various silicon heterocyclic systems such as benzosiloxaboroles, spiro-bis(siloxa)borinate, benzosilalactone and benzophosphoxasilole. In addition, intermolecular reduction of benzaldehydes with ortho-boronated arylsilane was observed whereas compounds bearing other reducible functional groups (COMe, COOEt, CN and NO2) were inert under comparable conditions. Specifically, an intramolecular reduction of the CN group in an ortho-silylated benzonitrile derivative was observed. The mechanism of Si-H bond activation was investigated by the DFT theoretical calculations. The calculations showed that the intramolecular coordination of the silicon atom effectively prevents the cleavage of the Si-aryl bond. Furthermore, the reaction is favored in anionic systems bearing COO-, B(OH)3- or CH2O- groups, while in the case of neutral functional groups such as PO(OEt)2 the process is much slower.
Reactions of aromatic compounds with xenon difluoride
Bardin,Adonin, N. Yu.
, p. 1400 - 1407 (2016/11/29)
Reactions of substituted benzenes C6H5R (R = Me, F, Cl, Br, CF3, NO2) with xenon difluoride in the presence of boron trifluoride–diethyl ether complex in weakly acidic (1,1,1,3,3-pentafluorobutane) and weakly basic media (acetonitrile) have been studied. These reactions lead to the formation of fluorobenzene derivatives FC6H4R (isomer mixture) together with isomeric difluorobenzenes and fluorinated and non-fluorinated biphenyls. The results have been compared with previously reported data obtained in other solvents using other catalysts.
Fluorination of aromatic compounds with xenon difluoride in the presence of boron trifluoride etherate
Fedorov,Zubarev,Mortikov, V. Yu.,Rodinovskaya,Shestopalov
, p. 1049 - 1052 (2016/02/09)
Fluorination of benzene with the XeF2 - BF3?Et2O system in acetonitrile at low temperatures affords fluorobenzene in 18% yield, the conversion of benzene being 92%. The rest products are di-, tri-, tetra-, and polyphenyls with different fluorination pattern. Toluene and chloro- and bromobenzenes are fluorinated predominantly at the ortho and para positions. Fluorination of 4-nitroanisole affords 2-fluoro-4-nitroanisole in 73% yield.
Halogen exchange via a halogenation of diaryliodonium salts with cuprous halide
Li, Jian,Liu, Li,Ding, Dong,Sun, Jiang-Tao
, p. 541 - 548 (2014/01/06)
An efficient halogenation reaction has been developed with diaryliodonium salts and cuprous halides. Various diaryliodonium salts 1 could perform the reaction with readily available CuBr or CuCl in CH3CN at 80°C, assembling bromoarenes or chloroarenes in up to 92% yields. This provides us a method for the transformation from iodoarenes to other haloarenes.
Development of a large scale asymmetric synthesis of the glucocorticoid agonist BI 653048 BS H3PO4
Reeves, Jonathan T.,Fandrick, Daniel R.,Tan, Zhulin,Song, Jinhua J.,Rodriguez, Sonia,Qu, Bo,Kim, Soojin,Niemeier, Oliver,Li, Zhibin,Byrne, Denis,Campbell, Scot,Chitroda, Ashish,Decroos, Phil,Fachinger, Thomas,Fuchs, Victor,Gonnella, Nina C.,Grinberg, Nelu,Haddad, Nizar,Jaeger, Burkhard,Lee, Heewon,Lorenz, Jon C.,Ma, Shengli,Narayanan, Bikshandarkoil A.,Nummy, Larry J.,Premasiri, Ajith,Roschangar, Frank,Sarvestani, Max,Shen, Sherry,Spinelli, Earl,Sun, Xiufeng,Varsolona, Richard J.,Yee, Nathan,Brenner, Michael,Senanayake, Chris H.
, p. 3616 - 3635 (2013/06/04)
The development of a large scale synthesis of the glucocorticoid agonist BI 653048 BS H3PO4 (1·H3PO4) is presented. A key trifluoromethyl ketone intermediate 22 containing an N-(4-methoxyphenyl)ethyl amide was prepared by an enolization/bromine-magnesium exchange/electrophile trapping reaction. A nonselective propargylation of trifluoromethyl ketone 22 gave the desired diastereomer in 32% yield and with dr = 98:2 from a 1:1 diastereomeric mixture after crystallization. Subsequently, an asymmetric propargylation was developed which provided the desired diastereomer in 4:1 diastereoselectivity and 75% yield with dr = 99:1 after crystallization. The azaindole moiety was efficiently installed by a one-pot cross coupling/indolization reaction. An efficient deprotection of the 4-methoxyphenethyl group was developed using H3PO4/anisole to produce the anisole solvate of the API in high yield and purity. The final form, a phosphoric acid cocrystal, was produced in high yield and purity and with consistent control of particle size.
Synthesis of aryl fluorides on a solid support and in solution by utilizing a fluorinated solvent
Doebele, Marion,Vanderheiden, Sylvia,Jung, Nicole,Braese, Stefan
supporting information; experimental part, p. 5986 - 5988 (2010/10/01)
(Figure Presented) F for fast: The perfluorinated solvent C 6F14 is the key to a new variant of the BalzSchiemann reaction for the synthesis of fluorinated arenes. Triazenes are converted into fluoroarenes under mild con-ditions on a support and in solution (see scheme). The method is straightforward and inexpensive, and yields previously difficult-to-prepare fluoroarenes in high purity.
Route to prepare 4-bromo-1-oxypentafluorosulfanylbenzene
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Page/Page column 4, (2008/06/13)
A process for preparing bromo-1-oxypentafluorosulfanylbenzene is provided, the process including the step of brominating pentafluorosulfanyloxybenzene with a bromination agent to provide the bromo-1-oxypentafluorosulfanylbenzene. The process is more effective than prior art processes for preparing such compounds.
Method for producing tetrakis ( fluoroaryl) borate-magnesium compound
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, (2008/06/13)
Fluoroaryl magnesium halide is reacted with a boron compound so that a molar ratio of the fluoroaryl magnesium halide to the boron compound is not less than 3.0 and not more than 3.7, so as to produce a tetrakis (fluoroaryl) borate·magnesium compound. With this method, there occurs no hydrogen fluoride which corrodes a producing apparatus and requires troublesome waste water treatment.
