- CATALYTIC AND STOICHIOMETRIC BROMINATION OF AROMATIC COMPOUNDS IN AQUEOUS TRIFLUOROACETIC ACID IN THE PRESENCE OF NITROGEN-CONTAINING OXIDIZING AGENTS
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The mono- and polybromination of benzene, halogenobenzenes, toluene, p-xylene, anisole, biphenyl, benzotrifluoride, benzoic acid, p-nitro- and p-carboxytoluene, p-methoxybenzonitrile, tetralin, and naphtalene were studied in trifluoroacetic acid and its aqueous solutions in systems containing stoichiometric amounts of bromine or alkali-metal bromide and stoichiometric or catalytic (in the presence of oxygen or air) amounts of nitrogen-containing oxidizing agent (nitrogen(IV) oxide, alkali-metal nitrate or nitrite).It is suggested that the brominating agent under the investigated conditions is nitryl bromide NO2Br.Under the conditions of catalytic bromination anthracene is oxidized to anthraquinone with a preparative yield.
- Cheprakov, A. V.,Makhon'kov, D. I.,Rodkin, M. A.,Beletskaya, I. P.
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p. 217 - 223
(2007/10/02)
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- TETRAHALOBENZENES AS DI-ARYNE EQUIVALENTS IN POLYCYCLIC ARENE SYNTHESIS
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1,2,4,5-Tetrabromobenzenes and analogous naphthalenes react with one or two equivalents of n-butyllithium and various dienes (furans, pyroles, cyclopentadienes, fulvenes) to form mono- or bis-cycloadducts.Highly substituted arenes can be obtained by removing the oxygen or nitrogen bridges from the furan or pyrrole adducts.By choice of conditions, two identical or two different rings can be fused to the di-aryne equivalent.Improved short syntheses of permethylnaphthalene, -anthracene and -naphthacene are described.A new triphenylene synthesis is presented.
- Hart, Harold,Lai, Chung-yin,Nwokogu, Godson Chukuemaka,Shamouilian, Shamouil
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p. 5203 - 5224
(2007/10/02)
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- Process for the complete bromination of non-fused ring aromatic compounds
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There is disclosed a process for the preparation of completely brominated derivatives of aromatic compounds comprising one or more phenyl groups which may contain substituents, side chains or be partially-brominated. The complete bromination is effected by utilizing liquid bromine as a reaction solvent whereby the starting aromatic material is reacted with an excess of bromine which contains a bromination catalyst and the mixture is refluxed for a sufficient time. Use of these brominated derivatives as fire retarding agents is nylon and polyester is also disclosed.
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