- PROCESS FOR THE PREPARATION OF DIARYL CARBONATE
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The invention relates to a process for the preparation of a diaryl carbonate by transesterification of an aromatic alcohol with a dialkyl carbonate in the presence of a transesterification catalyst during a period of time [ta], in which the aryl moiety is selected from unsubstituted phenyl and mono-, di- and trisubstituted phenyl groups, in which the alkyl moiety is selected from C2 to C4 linear and branched alkyl groups, in which the catalyst concentration is designated [ca], expressed as gram catalyst per gram of aromatic alcohol and dialkyl carbonate, in which the period of time [tm] and catalyst concentration [cm] are determined to arrive at a pre-set approach to the equilibrium for the transesterification of the aromatic alcohol with dimethyl carbonate to methyl aryl carbonate and methanol, in which the product [ca]*ta is at least 1.5* [cm]*tm, under otherwise the same reaction conditions.
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Page/Page column 19-23
(2008/12/07)
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- N-(ortho-Aryloxyphenyl)arylimidoyl Radicals: Novel 1,5-Aryl Radical Translocation from Oxygen to Carbon
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Imidoyl radicals 4a-d, obtained by hydrogen abstraction from imines 1a-d, give 7-membered cyclisation leading to oxazapines 2a-d.The intermediate spirocyclohexadienyl radicals of the competitive 6-membered ring closure (6a-d) rearrange to aryloxy radicals , giving benzophenones 3a-d: the whole process entails a novel 1,5-aryl radical translocation from an oxygen to a carbon atom.
- Guidotti, Simona,Leardini, Rino,Nanni, Daniele,Pareschi, Patrizia,Zanardi, Giuseppe
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p. 451 - 454
(2007/10/02)
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- REACTION OF ORGANIC CARBONATES WITH AMINES I. REACTION OF ALKYL PHENYL CARBONATES WITH PRIMARY ALIPHATIC AMINES
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The reaction of alkyl phenyl carbonates with primary aliphatic amines, leading to the formation of N-alkylurethanes, was investigated.The reaction has overall third order, which is explained by the catalytic action of the amine.The effect of the structure of the alkyl radical and the character of the substituent in the phenyl group of the alkyl phenyl carbonates and also the effect of the polarity of the solvent on the rate of the transformation were investigated.The reaction obeys the Hammett equation.
- Mikheev, V. V.,Svetlakov, N. V.,Garipov, R. M.
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p. 215 - 220
(2007/10/02)
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