2713-34-0Relevant articles and documents
Preparation method of 3, 5-difluorophenol
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Paragraph 0029; 0049-0063, (2021/05/12)
The invention provides a 3, 5-difluorophenol preparation method, which comprises the steps of S1, dissolving 3, 5-difluorobromobenzene in an organic solvent under inert gas protection, adding a bromine pulling agent to carry out a bromine pulling reaction, adding boric acid, filtering, and drying under reduced pressure to obtain 3, 5-difluorophenylboronic acid, and S2, dissolving the 3, 5-difluorophenylboronic acid, and adding an oxidizing agent and a catalyst to obtain the 3, 5-difluorophenol. The 3, 5-difluorophenol preparation method provided by the invention has the advantages of short steps and high yield, and is suitable for industrial production.
Synthesis method of 3, 5-difluorophenol
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, (2021/04/07)
The invention discloses a synthetic method of 3, 5-difluorophenol, and belongs to the technical field of chemical synthesis. According to the method, 3,5-difluorophenolate is obtained through a one-pot reaction of 2,4,6-trifluorobenzoic acid in a solvent under the action of alkali, 3,5-difluorophenol is obtained after acid regulation and dissociation, and the method has the advantages of cheap and easily available raw materials, short synthesis steps, simple operation, mild reaction conditions, high synthesis yield, good product quality, suitability for industrial production and the like. According to the method, cheap and easily available pentachloronitrile is taken as a raw material, 2, 4, 6-trifluoro-3, 5-dichlorobenzonitrile is obtained through a fluorination reaction, 2, 4, 6-trifluoro-3, 5-dichlorobenzoic acid is obtained through a hydrolysis reaction, and finally, the raw material 2, 4, 6-trifluoro-3, 5-dichlorobenzoic acid is synthesized through a selective dechlorination reaction, so that simple, cheap and efficient preparation of the raw material 2, 4, 6-trifluorobenzoic acid is realized, and the industrial application value of the synthesis process is improved.
Synthesis method of fluorine-containing phenol structure compound
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Paragraph 0029-0030, (2021/03/13)
The invention discloses a synthesis method of a fluorine-containing phenol structure compound, and belongs to the technical field of chemical synthesis. Fluorine-containing benzoic acid is subjected to a one-pot reaction in a solvent under the action of alkali to obtain fluorine-containing phenate, and fluorine-containing phenol is obtained after acid regulation and dissociation. The synthesis method has the advantages of rich, cheap and easily available raw material structure, short synthesis steps, mild reaction conditions, simple and convenient operation, high synthesis yield, good productquality, wide application range and the like, and is suitable for simple and efficient synthesis of various high-value and high-purity fluorine-containing phenol compounds.
Method for preparing 3,5-difluorophenol
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Paragraph 0011; 0025-0031, (2018/03/25)
The invention discloses a method for preparing 3,5-difluorophenol, wherein the method includes the following specific steps: (a) raw material preparation; (b) diazonium salt preparation: dropwise adding 3,4,5-trifluoroaniline into a sulfuric acid solution with the mass fraction of 50%; (c) reaction; (d) diazonium salt hydrolysis: adding a 50% hypophosphite solution, adding a catalyst, dropwise adding the diazonium salt solution, and stirring; and (e) separation and purification: carrying out extractive rectification, to obtain the target compound. The synthetic route of the designed process isrelatively simple, the raw materials are easy to get, the cost is low, the conditions are mild, and the yield is relatively high; the method is a relatively ideal synthetic method; the target compound is widely used, and is suitable for industrialized production.
A synthetic phenol method of multi-fluoro compounds (by machine translation)
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Paragraph 0030, (2016/10/20)
A synthetic phenol method of multi-fluoro compounds, Chinese the solvent, the compound (I) under the action of the catalyst, the reaction temperature 100-180°C, the reaction pressure of 0.3-2.0 MPa, the reaction time 6-12h react under, and then the step (a) in the reaction materials of the formula (II) compound of a post-processing, the process yield can be up to 80% or more, is far higher than the yield of the process the obtained in the past, to achieve product purity 99.5% or more, good color appearance, with mild reaction conditions, high yield, low cost and environment-friendly and the like. (by machine translation)
Catalytic defluorination of perfluorinated aromatics under oxidative conditions using N-bridged diiron phthalocyanine
Colomban, Cédric,Kudrik, Evgenij V.,Afanasiev, Pavel,Sorokin, Alexander B.
supporting information, p. 11321 - 11330 (2014/11/07)
Carbon-fluorine bonds are the strongest single bonds in organic chemistry, making activation and cleavage usually associated with organometallic and reductive approaches particularly difficult. We describe here an efficient defluorination of poly- and perfluorinated aromatics under oxidative conditions catalyzed by the μ-nitrido diiron phthalocyanine complex [(Pc)Fe III(μ-N)FeIV(Pc)] under mild conditions (hydrogen peroxide as the oxidant, near-ambient temperatures). The reaction proceeds via the formation of a high-valent diiron phthalocyanine radical cation complex with fluoride axial ligands, [(Pc)(F)FeIV(μ-N)FeIV(F) (Pc+?)], which was isolated and characterized by UV-vis, EPR, 19F NMR, Fe K-edge EXAFS, XANES, and Kβ X-ray emission spectroscopy, ESI-MS, and electrochemical techniques. A wide range of per- and polyfluorinated aromatics (21 examples), including C6F6, C6F5CF3, C6F5CN, and C6F5NO2, were defluorinated with high conversions and high turnover numbers. [(Pc)FeIII(μ-N)Fe IV(Pc)] immobilized on a carbon support showed increased catalytic activity in heterogeneous defluorination in water, providing up to 4825 C-F cleavages per catalyst molecule. The μ-nitrido diiron structure is essential for the oxidative defluorination. Intramolecular competitive reactions using C6F3Cl3 and C6F3H 3 probes indicated preferential transformation of C-F bonds with respect to C-Cl and C-H bonds. On the basis of the available data, mechanistic issues of this unusual reactivity are discussed and a tentative mechanism of defluorination under oxidative conditions is proposed.
CuII-β-cyclodextrin complex as a nanocatalyst for the homo-and cross-coupling of arylboronic acids under ligand-and base-free conditions in air: Chemoselective cross-coupling of arylboronic acids in water
Kaboudin, Babak,Abedi, Yaghoub,Yokomatsu, Tsutomu
experimental part, p. 6656 - 6662 (2012/01/06)
We report here the transition-metal-catalyzed chemoselective cross-coupling of arylbroronic acids in high yields without using ligand or base. We have developed an efficient copper-catalyzed protocol for the homocoupling and cross-coupling of arylboronic acids. The protocol is also suitable for the cross-coupling of aliphatic primary amines with arylboronic acids. Aminophenols and primary amines bearing an alcoholic substituent on the aliphatic chain were coupled with arylboronic acids, and the products were obtained with high C-N coupling selectivity. An effective catalyst was Cu2-β- cyclodextrin, which is readily available and structurally simple, but has not previously been explored as a catalyst.
Kinetics and mechanisms of the photolytic and OH° radical induced oxidation of fluorinated aromatic compounds in aqueous solutions
Karpel vel Leitner,Gombert,Ben Abdessalem,Dore
, p. 893 - 906 (2007/10/03)
Laboratory experiments with H2O2/UV oxidation processes and photolysis at 253.7 nm wavelength have been carried out on dilute aqueous solutions (C0 = 0.1 to 3.0 mM) of trifluorobenzene derivatives (1,3,5-trifluorobenzene, 1,2,3 and 1,2,4-trifluorobenzene) and of α,α,α-trifluorotoluene in the presence and in the absence of dissolved oxygen. The analyses of fluoride ions content during the oxidation experiments showed that the first steps lead to the production of about 2 mol of F-/mol of trifluorobenzene decomposed and of 1 mol of F-/mol of trifluorotoluene decomposed. Kinetic studies lead to the determination of the quantum yield for the photolysis of 1,3,5-trifluorobenzene, 1,2,3 and 1,2,4-trifluorobenzene (Φ = 0.011, 0.010 and 0.015 respectively), and of trifluorotoluene (Φ = 0.015). The rate constants for the reaction of hydroxyl radicals with these molecules, determined under specific experimental conditions, were found to range from 3.7 109 to 4.9 109 M-1.s-1). GC/MS analyses carried out on extracts at different irradiation time (UV, H2O2/UV) lead to the identification of numerous by-products from trifluorobenzene and trifluorotoluene. They consist mostly in hydroxylated and dehalogenated compounds. Dimers have also been observed during photolysis. Moreover, experiments carried out under oxygen limiting conditions revealed the formation of other compounds. For each case studied, a detailed mechanism involving radical intermediates and the different reaction sequences is proposed.
Regiospecific hydroxylation in aromatic series by the organosilicon pathway
Prouilhac-Cros, Sylvie,Babin, Pierre,Bennetau, Bernard,Dunogues, Jacques
, p. 513 - 516 (2007/10/02)
Regiospecific hydroxylation of functional arylsilanes by hydrogen peroxide (30percent) or by bis(trimethylsilyl) peroxide, in the presence of a stoichiometric amount of fluoride ions, gives the corresponding phenols in good yields. regiospecific hydroxylation / phenol / hydrogen peroxide / bis(trimethylsilyl) peroxide / arylsilane
Stereopopulation Control. 7. Rate Enhancement in the Lactonization of 3-(o-Hydroxyphenyl)propionic Acids: Dependence on the Size of Aromatic Ring Substituents
King, Michael M.,Cohen, Louis A.
, p. 2752 - 2760 (2007/10/02)
A series of 4,4-dimethyl-6-hydroxyhydrocoumarins was synthesized with various combinations of methyl and halogen groups at C-5 and C-7.The 5,7-difluoro compound was obtained by condensation of difluorohydroquinone with dimethylacrylic ester.Controlled chlorination of the parent phenolic lactone provided the 5- and 7-chloro isomers, in addition to the 5,7-dichloro product.On the other hand, bromination gave both the 5,7-dibromo and 7-bromo products, without trace of the 5-bromo isomer; finally, iodination gave only the 7-iodo product.These compounds were converted into 6-mesylates as protection against air oxidation of the hydroquinone system in alkaline media.The lactones were hydrolyzed in aqueous base, and the kinetics of relactonization were measured at 30 deg C over a wide pH range.As previously shown for similar systems, lactonization is subject to both general acid and general base catalysis.After adjustment of the rate constants (k') for the electronic effects of ring substituents, the residual rate constants (k'') were found to increase with the size of the C-5 substituent, the value for bromine being 4800 times that for hydrogen.A plot of log k''cat vs. the van der Waals radius of the substituent is linear, demonstrating the existence of a free energy continuum in the relationship between k'' for lactonization and the conformational mobility of the three-carbon side chain.
