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The hydrolysis of nitriles has previously been stopped at the intermediate amide stage by employing concentrated sulfuric acid (1), hydrogen peroxide with sodium hydroxide (2), or polyphosphoric acid (3).We have accomplished this by means of boron fluoride in aqueous acetic acid with which various nitriles were converted exclusively to the corresponding amides (Table I). The method usually involved saturating a solution of the nitrile in aqueous acetic acid with boron fluoride under which conditions the temperature of the reaction mixture rose to 115-135°( Procedure A). Equally good results were obtained by heating the nitrile at 115-120°for ten minutes with a boron fluoride-acetic acid complex2 to which had been added some water (Procedure B). In both procedures the reaction mixtures were subsequently decomposed with alkali.We further found that by treatment with the boron fluoride-acetic acid com-plex2 (anhydrous) certain of the nitriles were converted exclusively to amides but certain others produced mixtures of amides and acids (Table II).It can be seen from Table I that the aqueous acetic acid reagent produced excellent yields of the amide, which, without recrystallization, usually melted within a degree or two of the recorded value. For example, phenylacetonitrile and benzonitrile were converted almost quantitatively to phenylacetamide and benzamide respectively. However, the method failed with mesitonitrile which was recovered unchanged. The recent polyphosphoric acid method (3) likewise

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