Question

Phenyl isocyanide is formed when chloroform is treated with alcoholic potassium hydroxide and:

• A. Benzaldehyde
• B. Aniline
• C. Phenol
• D. Nitrobenzene

Answer 1

The correct option is B

Aniline

Explanation:

Carbylamine Test:

• The Carbylamine test is used to distinguish primary amines(aliphatic or aromatic) from secondary and tertiary amines.
• When primary amine is heated with the chloroform in the presence of alcoholic Potassium hydroxide ($\mathrm{KOH}$) forms carbylamines or isocyanide having an unpleasant smell.

Formation of Phenol isocyanide

• Phenyl isocyanide is formed when the chloroform is heated with the aniline(1^o amine) in presence of alcoholic potassium hydroxide.
• Reaction involved:- $\underset{\mathrm{Phenylamine}}{{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2}+\underset{\mathrm{Chloroform}}{{\mathrm{CHCl}}_3}+\underset{\mathrm{Potassium}\mathrm{hydroxide}}{3\mathrm{KOH}}\to \underset{\mathrm{Phenyl}\mathrm{isocyanide}}{{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{NC}}+\underset{\mathrm{Potassium}\mathrm{chloride}}{3\mathrm{KCl}}+\underset{\mathrm{Water}}{3{\mathrm{H}}_2\mathrm{O}}$

Therefore, the correct answer is (B).