CATALYSIS IN ORGANIC CHEMISTRY. II 391 chloride; ketones are formed by the introduction of an acetyl or benzoyl group into the aromatic nucleus.Acetic, chloro-acetic, propionic, «-butyric, isovaleric, oxalic, malonic, succinic, benzoic, phenylacetic, hydrocinnamic, ^-toluic, mandelic, anisic, f-chlorobenzoic, o-, m-and p-nitrobenzoic, 3,5-dinitrobenzoic, p-aminobenzoic, o-phthalic and diphenic acids and the anhydrides of acetic, propionic, «-butyric, isovaleric, succinic, benzoic, o-phthalic and diphenic acids are converted into ethyl esters by treatment with anhydrous ethyl ether containing dry hydrogen bromide. Stearic, picric, ^-toluenesulfonic and 2,4,-6-trinitrobenzoic acids do not react with ethyl ether in the presence of hydrogen bromide.Cambridge, Massachusetts