What is A in the following reaction?

Solution

Chemistry ma’am · 3 steps

Gabriel synthesis: phthalimide puts N on the benzyl carbon, then hot base sets the primary amine free.

1. Step (i), SN2. The phthalimide anion is a good nitrogen nucleophile. It attacks the CH₂ carbon of benzyl bromide and pushes out Br⁻, giving N-benzylphthalimide. The nitrogen now carries just one carbon group.
2. Step (ii), hydrolysis. Hot aqueous OH⁻ attacks both C=O groups of the imide and breaks both C-N bonds. The phthalic part leaves as the phthalate ion, and the nitrogen keeps only the benzyl group plus two H atoms.

   C₆H₅CH₂Br →((i) phthalimide⁻K⁺) C₆H₅CH₂N(CO)₂C₆H₄ →((ii) OH⁻/H₂O) C₆H₅CH₂NH₂

3. So. A is benzylamine, C₆H₅CH₂NH₂, which is option (d).

The idea to keep. Gabriel synthesis turns an alkyl or benzyl halide into a pure primary amine, with no secondary or tertiary amine formed. It cannot make aniline, because aryl halides do not undergo SN2.

Answer from the NTA final answer key. Solution by PrepWiser.