The Gabriel synthesis is a method for synthesizing primary amines from primary alkyl halides using phthalimide as the nitrogen source. The reaction mechanism involves the following steps:1. Formation of phthalimide anion:Phthalimide is treated with a strong base, such as potassium hydroxide KOH or sodium hydride NaH , which deprotonates the acidic NH proton of phthalimide, generating a phthalimide anion.Phthalimide + Base Phthalimide anion + Conjugate acid of the base2. Nucleophilic substitution:The phthalimide anion, acting as a nucleophile, attacks the primary alkyl halide in a nucleophilic substitution reaction usually SN2 mechanism . This results in the formation of an N-alkyl phthalimide.Phthalimide anion + Primary alkyl halide N-alkyl phthalimide + Halide ion3. Hydrolysis:The N-alkyl phthalimide is then hydrolyzed, typically using aqueous hydrochloric acid HCl and heat. This step cleaves the N-alkyl group from the phthalimide, yielding the primary amine and phthalic acid.N-alkyl phthalimide + HCl + H2O Primary amine + Phthalic acidOverall, the Gabriel synthesis allows for the preparation of primary amines without the formation of secondary or tertiary amine byproducts, which can be a problem in other amine synthesis methods.