Question

Assertion (A): Aromatic primary amines can be prepared by Gabriel phthalimide synthesis. Reason (R): Aryl halides do not undergo nucleophilic substitution with phthalimide ion. Choose the correct option:

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Gabriel synthesis works only for aliphatic primary amines. It does not work for aryl halides → Aromatic amines cannot be prepared this way.

Answer 1

The Correct Option is D

The given question presents an Assertion (A) and a Reason (R). We need to evaluate the correctness of both statements and determine the relationship between them. Let's examine each statement:

1. Assertion (A): Aromatic primary amines can be prepared by Gabriel phthalimide synthesis.
   • Gabriel phthalimide synthesis is primarily used to prepare aliphatic primary amines. It involves reacting a potassium phthalimide with an alkyl halide, followed by hydrolysis to release the primary amine.
   • However, this method is not applicable for preparing aromatic primary amines because aryl halides like chlorobenzene do not participate in nucleophilic substitution reactions required for this synthesis.
   • Therefore, the assertion is false.
2. Reason (R): Aryl halides do not undergo nucleophilic substitution with phthalimide ion.
   • This statement is true because aryl halides are generally resistant to nucleophilic substitution due to the stability of the aromatic ring and the nature of the C-X bond in aryl halides, which is stronger than in alkyl halides.
   • Hence, the reason is true.

Now, let's determine the relationship between the Assertion and the Reason:

• The Assertion (A) is false, but the Reason (R) is true. The Reason correctly explains the limitations of Gabriel phthalimide synthesis regarding aryl halides, not aromatic primary amines.

Therefore, the correct answer is:

Assertion (A) is false, but Reason (R) is true.