Question

Which among following statements is NOT true about Gabriel phthalimide synthesis?

• A. In this method formation of N-alkyl phthalimide is involved.
• B. In this method sodium phthalate is also obtained.
• C. This method is useful for preparation of aromatic amines.
• D. In this method potassium salt of phthalimide is formed as an intermediate product.

Hint:

Gabriel phthalimide synthesis is strictly reserved for creating pure aliphatic $1^\circ$ amines. Aryl halides are too stubborn to undergo the necessary nucleophilic substitution step, completely ruling out aromatic amines!

Answer 1

The Correct Option is C

Step 1: Recall the steps.
In Gabriel synthesis, phthalimide gives its potassium salt, then reacts with an alkyl halide to form N-alkyl phthalimide, and hydrolysis gives a primary amine plus sodium phthalate. So three of the statements are true.

Step 2: Test the aromatic claim.
Aryl halides do not react well in this substitution because the C to X bond has partial double bond character. So aromatic amines cannot be made this way.

Step 3: Pick the false one.
The statement that the method makes aromatic amines is wrong.
\[ \boxed{\text{Useful for aromatic amines, option 3}} \]