- Microwave-assisted synthesis of 1,4-bis(difluoromethyl)benzene
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A fast, mild, and practical microwave-assisted protocol for synthesis of 1,4-bis(difluoromethyl)benzene from 1,4-bis(dichloromethyl)benzene and KF was developed. The new protocol increased the yield and reduced the reaction time significantly in contrast to the conventional heating procedure. Also, the synergistic effect of a composite phase transfer catalyst was studied.
- Pan, Dong-Hui,Wang, Tong-Zhen,Xiao, Guo-Min
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- Direct Difluoromethylation of Aryl Halides via Base Metal Catalysis at Room Temperature
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A stable and isolable difluoromethyl zinc reagent has been prepared through the reaction of ICF2H with diethyl zinc and DMPU. This new zinc reagent is a free-flowing solid and can be used in combination with a nickel catalyst to difluoromethylate aryl iodides, bromides, and triflates at room temperature. Such mild conditions for the catalytic difluoromethylation of these substrates are unprecedented.
- Xu, Long,Vicic, David A.
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supporting information
p. 2536 - 2539
(2016/03/12)
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- Preparation of Mono-/Difluorinated Hydrocarbon Compounds
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Mono- or difluorinated hydrocarbon compounds are prepared from an alcohol or a carbonylated compound by reacting one of these with a fluorinating reagent, optionally in the presence of a base, the fluorinating agent comprising a pyridinium reactant having the following formula (F), wherein R0 is an alkyl or cycloalkyl radical:
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Page/Page column 11-12
(2009/09/28)
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- Efficient synthesis of p-bis-(chlorodifluoromethyl)benzene
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Selective, high yield partial fluorination of p-bis-(trichloromethyl)benzene to p-bis-(chlorodifluoromethyl)benzene has been accomplished by warming a slurry of the p-bis-(trichloromethyl)benzene in anhydrous HF which also contains a small quantity of inert solvent, such as 1,2-dichloroethane.
- Dolbier Jr., William R.,Duan, Jian-Xin,Rong, Xiao X.
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p. 1091 - 1093
(2008/02/08)
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- Method for transferring TCPX into TFPX
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A method for transferring TCPX (α, α, α′, α′-tetrachloro-p-xylene) into TFPX (α, α, α′, α′-tetrafluoro-p-xylene) is disclosed, which comprises the following steps: (a) providing a first reactant comprising TFPX; (b) mixing the first reactant with alkali metal fluorides, TCPX and phase transfer catalyst(s) to form a mixture, wherein the alkali metal fluorides is KF, CsF, NaF, LiF or the combination thereof, the phase transfer catalyst(s) is quaternary ammonium salt, quaternary phosphonium salt or the combination thereof; and (c) heating the mixture.
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Page/Page column 3
(2008/06/13)
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- Method for synthesizing TFPX
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A method for the synthesis of TFPX (α,α,α′,α′-tetrafluoro-p-xylene) is disclosed, which comprises the following steps: (a) providing a sulpholane solution comprising TCPX (α,α,α′,α′-tetrachloro-p-xylene); (b) mixing the sulpholane solution with alkali metal fluoride, and phase transfer catalyst to form a mixture, wherein the phase transfer catalyst is quaternary phosphonium salt; and (c) heating the mixture.
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Page/Page column 2; 3
(2008/06/13)
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- METHOD FOR THE PREPARATION OF ALPHA,ALPHA,ALPHA',ALPHA'-TETRAFLUORO-P-XYLENE
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A method for the preparation of α,α,α′,α′-tetrafluoro-p-xylene is disclosed. α,α,α′,α′-tetrachloro-p-xylene and KF and a small amount of phase transfer catalyst are dissolved in solvent, xylene, and undergo a recycle reaction for 48 hours, after which 60% of the product is obtained.
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Page/Page column 3
(2008/06/13)
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- Process for production of 1,4-bis(difluoroalkyl)benzene derivative
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A process is provided which allows a 1,4-bis(difluoroalkyl)benzene derivative to be produced inexpensively by a simple procedure without requiring any special facility. This process comprises causing a compound (A) of the following formula (1): wherein X1, X2, X3, and X4 independently stand for an oxygen or sulfur atom, Y1 and Y2 independently stand for a group of the formula: —CnH2n—, in which n is 2 or 3, k is an integer in the range of 0 to 4, G stands for a halogen group, an alkyl group, a perfluoroalkyl group, or an alkoxy group, and m is an integer in the range of 0 to 4, to react with a fluorine-containing species, the molar ratio of the fluorine-containing species to compound (A) being in the range of 20-40. The process is carried out in the presence of a bromine-containing compound, which is in an amount of 2 to 3 equivalences to the amount of compound (A), in an organic solvent at ?80° C. to 30° C., the final concentration of compound (A) being in the range of 3 to 30% by weight.
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- Process for production of 1,4-bis (difluoroalkyl) benzene derivative
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A process is provided which allows a 1,4-bis(difluoroalkyl)benzene derivative to be produced inexpensively by a simple procedure without requiring any special facility. This process comprises causing a compound (A) of the following formula (1): wherein X1, X2, X3, and X4 independently stand for an oxygen or sulfur atom, Y1 and Y2 independently stand for a group of the formula: —CnH2n—, in which n is 2 or 3, k is an integer in the range of 0 to 4, G stands for a halogen group, an alkyl group, a perfluoroalkyl group, or an alkoxy group, and m is an integer in the range of 0 to 4, to react with a fluorine-containing species, the molar ratio of the fluorine-containing species to compound (A) being in the range of 20-40. The process is carried out in the presence of a bromine-containing compound, which is in an amount of 2 to 3 equivalences to the amount of compound (A), in an organic solvent at ?80° C. to 30° C., the final concentration of compound (A) being in the range of 3 to 30% by weight.
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- Method for production of fluorine-containing aromatic compounds
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A method for the production of a fluorine-containing aromatic compound is provided which allows the relevant reaction to proceed in a standard reaction vessel such as, for example, a glass vessel at room temperature under an ambient pressure without requiring provision of such special devices as have been necessary heretofore or adoption of harsh reaction conditions. This method comprises causing an aromatic compound (A) having a cyclic skeletal part of 6 to 16 carbon atoms containing a plurality of -C(=O)X groups, wherein X stands for a hydrogen atom, a halogen atom, or an alkyl group of 1 to 10 carbon atoms, and having the remaining hydrogen atoms unsubstituted or partly or wholly substituted with at least one species of halogen atom to react with a compound (B) represented by the formula: wherein R1 and R2 independently stand for an alkyl group of 1 to 6 carbon atoms or a phenyl group.
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- Bis(2-methoxyethyl)aminosulfur trifluoride: A new broad-spectrum deoxofluorinating agent with enhanced thermal stability
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Bis(2-methoxyethyl)aminosulfur trifluoride, (CH3OCH2CH2)2NSF3 (Deoxo-Fluor reagent), is a new deoxofluorinating agent that is much more thermally stable than DAST (C2H5)2NSF3 and its congeners. It is effective for the conversion of alcohols to alkyl fluorides, aldehydes/ketones to the corresponding gem-difluorides, and carboxylic acids to the trifluoromethyl derivatives with, in some cases, superior performance compared to DAST. The enhanced stability is rationalized on the basis of conformational rigidity imposed by a coordination of the alkoxy groups with the electron-deficient sulfur atom of the trifluoride.
- Lal, Gauri S.,Pez, Guido P.,Pesaresi, Reno J.,Prozonic, Frank M.,Cheng, Hansong
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p. 7048 - 7054
(2007/10/03)
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- SYNTHESIS OF 1,1,2,2,9,9,10,10-OCTAFLUORO-PARA-CYCLOPHANE
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1,1,2,2,9,9,10,10-Octafluoro-para-cyclophane was obtained by the pyrolysis of α,α'-di-bromo-α,α,α',α'-tetrafluoro-p-xylene using argon as the diluent with further trapping of the pyrolysis products in boiling toluene.The pyrolysis zone was filled with a copper packing to bind bromine.An efficient scheme was also developed for the preparation of α,α'-dibromo-α,α,α',α'-tetrafluoro-p-xylene starting from p-xylene.
- Grechkina, E. V.,Sochilin, V. A.,Pebalk, A. V.,Kardash, I. E.
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p. 1663 - 1665
(2007/10/02)
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- A New Synthesis of Octafluoroparacyclophane
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A new synthesis of 1,1,2,2,9,9,10,10-octafluoroparacyclophane (2) is reported.Easy preparation of gram quantities of 2 is accomplished by treatment of α,α'-dibromo-α,α,α',α'-tetrafluoroxylene with a complex low-valent form of Ti which is made by reduction of TiCl4 with equimolar quantities of LiAlH4 in THF.Use of high-dilution techniques is required for the reaction to be successful.The formation of 2 is believed to proceed via the reactive monomeric species α,α,α',α'-tetrafluoro-p-xylylene (4).
- Dolbier, William R.,Asghar, Mohammed Ali,Pan, He-Qi,Celewicz, Lech
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p. 1827 - 1830
(2007/10/02)
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