- PROCESS FOR THE PREPARATION OF ORGANIC HALIDES
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The present invention provides a halo-de-carboxylation process for the preparation of organic chlorides, organic bromides and mixtures thereof, from their corresponding carboxylic acids, using a chlorinating agent selected from trichloroisocyanuric acid (TCCA), dichloroisocyanuric acid (DCCA), or combination thereof, and a brominating agent.
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Paragraph 00146
(2017/08/01)
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- Preparation process of fluorine substituted aromatic compound
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A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
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- Photo-Rearrangement of Polychlorobenzenes meta-Migration of Chlorine Atom
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Several polychlorobenzenes were irradiated by ultraviolet light (254 nm) in acetonitrile and the products were determined by gas chromatography.In addition to the abstraction of hydrogen atom from the solvent, photo-isomerization was shown to proceed giving isomeric polychlorobenzenes one of which chlorine atoms migrated to meta to the original position.The meta-rearrangement was rationalized by an MNDO calculation on o-chlorophenyl free radical.
- Morisaki, Kenji,Miura, Yasuki,Abe, Kazuhisa,Hirota, Minoru,Nakada, Masahiro
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p. 1589 - 1592
(2007/10/02)
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- New Method for Selective Monofluorination of Aromatics Using Silver Difluoride
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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.
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p. 3597 - 3603
(2007/10/02)
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