摘要：

Mixed carboxylic-carbonic anhydrides, prepared from oarboxylio acids, Methylamine and alkyl cblorocarbonates in an inert solvent at 0°, have been found to acylate diethyl malonate and diethyl ethylmalonate, at room temperature or below, in satisfactory yields. The compounds prepared by this procedure include diethyl benzoylmalonate (V, 68-75%), diethyl acetylmalonate (VI, 54%), diethyl benzoylethylmalonate (VII, 17%) and diethyl (acetylsalicyloyl)-malonate (VIII), identified by conversion to 3-carbethoxy-4-hydroxycoumarin in 45% over-all yield. Benzole-carbonic anhydride and diethyl cadmium give a 60% yield of propiophenone. Diazoacetophenone and diazomethyl isobutyl ketone are obtained from the corresponding mixed anhydrides and diazomethane. Low yields of 3,4-dimethoxybenzophenone have been obtained from the Friedel-Crafts reaction between the mixed benzoic anhydride and veratrole. This reaction has been shown to involve the mixed anhydride, and not other possible derived compounds, as the reactive intermediate. Phenols have been acylated by the mixed anhydrides. The acylation of alcohols by the mixed anhydrides to form carboxylic esters gives poor yields in general. The mixed anhydride from benzoic acid and 2,4-dimethylpentanol-3 chlorocarbonate yields mainly the benzoate of 2,4-dimethylpentanol-3 in the presence of ethanol and isoamyl alcohol indicating that the mixed anhydride probably undergoes an intramolecular reaction with alkyl-oxygen cleavage of the highly branched alkyl group. The mixed anhydrides appear to be useful reagents for acylation of active methylene groups, of organocadmium compounds, of phenols, of diazomethane, and possibly in some cases of alcohols; the essentially neutral conditions under which they are prepared, and the mild conditions under which they react, may make them the reagent of choice in dealing with acid-sensitive compounds.

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