- Three-step regioselective synthesis of 2,3-difluorohalobenzenes using tetrafluoroethylene and buta-1,3-diene as starting building blocks
-
The gas-phase copyrolysis of tetrafluoroethylene and buta-1,3-diene in a flow tube reactor at 490–510 °C gives 3,3,4,4-tetrafluorocyclohex-1-ene, which is selectively converted to 1-bromo- or 1-chloro-2,3-difluorobenzene via intermediate steps of halogenation and dehydrohalogenation.
- Egorov, M. P.,Lipkind, M. B.,Nefedov, O. M.,Volchkov, N. V.
-
p. 925 - 932
(2021/06/07)
-
- Reactions of aromatic compounds with xenon difluoride
-
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.
- Bardin,Adonin, N. Yu.
-
p. 1400 - 1407
(2016/11/29)
-
- Method for producing tetrakis ( fluoroaryl) borate-magnesium compound
-
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.
- -
-
-
- Process for producing chlorofluorobenzenes
-
A process for producing chlorofluorobenzenes, which comprises reacting fluorine-containing nitrobenzenes of the following formula (1) with chlorine gas to obtain chlorofluorobenzenes of the following formula (2): STR1 wherein n and m are integers satisfying 1≤n≤3, 0≤m≤2 and 1≤n+m≤3.
- -
-
-
- Process for preparing chloro-difluorobenzene
-
1-Chloro-3,4-difluoro-benzene, an intermediate in the production of certain quinolone drugs, is produced by converting a chlorofluoro-aniline into the corresponding diazonium fluoborate, and pyrolysing the latter to give the 1-chloro-3,4-difluorobenzene.
- -
-
-
- Preparation of substituted fluorobenzenes
-
Substituted fluorobenzenes are produced by pyrolyzing vinylfluorocyclobutanes at a temperature of 250°-450° C. in the presence of activated carbon or certain metal oxides or mixtures of metal oxides.
- -
-
-
- New Method for Selective Monofluorination of Aromatics Using Silver Difluoride
-
Fluorobenzene is obtained in 61percent yield from reaction of a solution of benzene in n-hexane with solid argentic fluoride (AgF2).The AgF2 acts as both a strong oxidant and the fluoride source.Cobaltic fluoride provides only low (8percent) yields of fluorobenzene under similar conditions.The predominant reaction of benzene solutions with AgF2 appears to proceed by a process involving initial electrophilic oxidative cis addition of two fluorine atoms from the solid AgF2 lattice to the para aromatic positions, leading to cis-3,6-difluoro-1,4-cyclohexadiene (F2CHD).The reductive elimination leaves solid argentous fluoride (AgF) which is easily recoverable by filtration.Elimination of HF from the F2CHD yields fluorobenzene.Reactions of haloaromatics with AgF2 generally proceed in a similar manner.Thus, further reaction of AgF2 with benzene or monohalo- or p-dihalobenzenes leads in steps to 3,3,6,6-tetrafluoro-1,4-cyclohexadiene (F4CHD) in up to 82percent yield.The modest to high yields of mono- and specific polyfluorinated aromatics contrast sharply with reported nonselective perfluorination in vapor-phase reactions of aromatics over AgF2 or CoF3.Reactions of AgF2 or CoF3 with solutions of nitrobenzene, acetophenone, benzoic acid, and benzonitrile give mixtures of o-, m-, and p-monofluoro derivatives.
- Zweig, Arnold,Fischer, Robert G.,Lancaster, John E.
-
p. 3597 - 3603
(2007/10/02)
-