Which of the following compound is responsible for foul smell in Carbylamine reaction?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Isocyanide
In the carbylamine reaction, a primary amine (aliphatic or aromatic) is heated with chloroform and ethanolic potassium hydroxide. The product is an isocyanide (carbylamine), a substance with a very unpleasant, foul smell:
\( \displaystyle \ce{R-NH2 + CHCl3 + 3KOH} \xrightarrow{\text{Heat}} \ce{R-NC + 3KCl + 3H2O} \)
Secondary and tertiary amines do not give this reaction. So the foul smell is a test for primary amines, and the compound responsible for it is the isocyanide, R–N≡C.
NCERT (2026-27 edition):
Carbylamine Reaction
