Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?
Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?
Gabriel phthalimide synthesis is used for the preparation of aliphatic primary amines. It involves nucleophilic substitution (SN2) of alkyl halides by the anion formed by the phthalimide. In this reaction, Potassium salt of phthalimide is formed. It reacts readily with alkyl halide to form the corresponding alkyl derivative.
But aryl halide does not react with potassium phthalimide. Because C-X bond in haloarene (alkyl halide) is difficult to be cleaved due to partial double bond character, moreover, aryl halides do not undergo nucleophilic substitution with the anion formed by the phthalimide. So, aromatic primaruy amines cannot be prepared by Gabriel phthalimide synthesis.
Gabriel phthalimide synthesis is used for the preparation of aliphatic primary amines. It involves nucleophilic substitution (SN2) of alkyl halides by the anion formed by the phthalimide. In this reaction, Potassium salt of phthalimide is formed. It reacts readily with alkyl halide to form the corresponding alkyl derivative.
But aryl halide does not react with potassium phthalimide. Because C-X bond in haloarene (alkyl halide) is difficult to be cleaved due to partial double bond character, moreover, aryl halides do not undergo nucleophilic substitution with the anion formed by the phthalimide. So, aromatic primaruy amines cannot be prepared by Gabriel phthalimide synthesis.
