Question

Which product is formed on carbylamine reaction with 4-methylaniline?

• A. A
• B. B
• C. C
• D. D

Hint:

Carbylamine reaction is a special test for primary amines only. The product always contains the isocyanide group \( \mathrm{-NC} \), not the nitrile group \( \mathrm{-CN} \).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The Carbylamine reaction (Isocyanide test) is a diagnostic test for primary amines. It produces an extremely foul-smelling isocyanide (carbylamine).
Step 2: Formula Application:
$R-NH_2 + CHCl_3 + 3KOH \xrightarrow{\Delta} R-NC + 3KCl + 3H_2O$.
Step 3: Explanation:
4-methylaniline ($p$-toluidine) is a primary aromatic amine. When reacted with chloroform and alcoholic KOH, the $-NH_2$ group is converted into an isocyanide group ($-NC$).
Step 4: Final Answer:
The product is 4-methylphenyl isocyanide ($CH_3—C_6H_4—NC$).