i2o PRACTICAL ORGANIC CHEMISTRY Hydrolysis of Benzamide. When acid amides are hydrolysed, the corresponding acid and ammonia are formed. Consequently the hydrolysis, which is extremely slow with water alone, is hastened con-C 6 H 6 CO NH 2 +HOH - C 6 H 5 COOH + NH 3 siderably by the addition of either caustic alkalis (which give the alkali salt of the acid and liberate ammonia) or mineral acids (which neutralise the ammonia and liberate the organic acid). Caustic alkalis usually effect the more rapid hydrolysis, and their use is to be preferred. Place i g. of benzamide and 15 ml. of 10% aqueous sodium hydroxide solution in a ioo ml. conical flask fitted with a reflux water-condenser, and boil the mixture gently for 30 minutes, during which period ammonia is freely evolved. Now cool the solution in ice-water, and add concentrated hydrochloric acid until the mixture is strongly acid. Benzoic acid immediately separates. Allow the mixture to stand in the ice-water for a few minutes, and then filter off the bcnzoic acid
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