Nitrile hydrolysis yields what under acidic or basic conditions?

• A. Alcohol
• B. Amide
• C. Nitrile
• D. Carboxylic acid

Answer: (D)

Nitrile hydrolysis aNH2 to carboxyl is all about turning the nitrile carbon into a carboxyl group through water addition and proton transfers. In acidic conditions, protonation of the nitrile increases the electrophilicity of the carbon; water attacks, giving an imidic intermediate that, after proton transfers, becomes an amide. A second equivalent of water then hydrolyzes that amide to a carboxylic acid, with ammonia produced as a byproduct. In basic conditions, hydroxide attacks the nitrile carbon directly, forming a carboxylate after hydrolysis, and upon acid workup you obtain the carboxylic acid. Thus the product of nitrile hydrolysis under either condition is a carboxylic acid (or its carboxylate salt in base). The amide is just an intermediate, not the final product, and the nitrile or an alcohol would come from different transformations.