Question

Which of the following amines is not obtained by Gabriel phthalimide synthesis?

• A. Aniline
• B. Benzyl amine
• C. Methyl amine
• D. Isobutyl amine

Hint:

Gabriel synthesis needs an alkyl halide for SN2, so aryl amines cannot be made.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Gabriel phthalimide synthesis converts primary alkyl halides to primary amines. Potassium phthalimide attacks the alkyl halide by an \(\text{S}_\text{N}2\) route, and then hydrolysis frees the amine.

Step 2: Apply:
Aryl halides do not undergo nucleophilic substitution under these conditions, because the C-X bond has partial double bond character and the ring blocks back-side attack. So aniline cannot be made.
Benzylamine (from benzyl chloride), methylamine (from methyl iodide) and isobutylamine (from isobutyl bromide) all come from primary alkyl halides, so they can be made.

Final Answer:
Aniline is not obtained by this method, option (A). \[ \boxed{\text{Aniline}} \]