Gabriel Primary Amine Synthesis

Abstract This reaction is a two‐step synthesis of primary aliphatic amines involving the N ‐alkylation of phthalimide followed by acidic or basic hydrolysis of N ‐alkyl‐phthalimides. The phthalimide has been reported to be easily deprotonated by KOH or NaOH because of the two electron‐withdrawing groups (i.e.,carbonyl), resulting in a good nucleophile; after the N ‐alkylation, the N ‐alkyl phthalimide can be decomposed to provide pure primary amines. This reaction is known as the Gabriel synthesis of primary amine. It is found that under basic conditions for the hydrolysis of N ‐alkyl phthalimide, the second step is the rate‐limiting step. The hydrolysis has been modified by using hydrazine. The reaction is generally used for the synthesis of aliphatic primary amines.