Question

Which of the following amines is obtained by using Gabriel phthalimide synthesis?

• A. \(\text{Ar-NH}_{2}\)
• B. \(\text{R-NH}_{2}\)
• C. \((\text{R})_{2}\text{-NH}\)
• D. \((\text{R})_{3}\text{-N}\)

Hint:

Gabriel synthesis gives only aliphatic primary amines.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Potassium phthalimide reacts with an alkyl halide and the product is hydrolysed to release a primary amine.

Step 2: Scope
The method gives pure aliphatic primary amines (\(\text{R-NH}_{2}\)).
Aryl halides do not undergo nucleophilic substitution with phthalimide anion, so aromatic amines are not formed.

Step 3: Compare the options
The amine obtained is \(\text{R-NH}_{2}\), option (B).

Final Answer:
Gabriel synthesis gives aliphatic primary amines. \[ \boxed{\text{(B) }\text{R-NH}_{2}} \]