The reaction of aliphatic and aromatic primary amines with chloroform in the presence of ethanolic potassium hydroxide to produce compound with foul smell, is known as
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Carbylamine reaction
In the carbylamine reaction the base first converts chloroform into dichlorocarbene, \( \ce{:CCl2} \), which reacts with the –\( \ce{NH2} \) group of a primary amine to give an isocyanide:
\( \displaystyle \ce{R-NH2 + CHCl3 + 3KOH} \xrightarrow{\Delta} \ce{R-NC + 3KCl + 3H2O} \)
\( \displaystyle \ce{C6H5NH2 + CHCl3 + 3KOH} \xrightarrow{\Delta} \ce{C6H5NC + 3KCl + 3H2O} \)
So the reaction is the carbylamine reaction.
Why the other options are incorrect
Option (1) Rosenmund reaction — Incorrect. An acyl chloride is reduced to an aldehyde by hydrogen over palladium on barium sulphate, \( \ce{RCOCl + H2 -> RCHO + HCl} \); amines are not involved.
Option (3) Fittig reaction — Incorrect. Two molecules of an aryl halide are joined by sodium in dry ether, \( \ce{2C6H5Cl + 2Na -> C6H5-C6H5 + 2NaCl} \), giving a diaryl.
Option (4) Etard reaction — Incorrect. Toluene is oxidised to benzaldehyde by chromyl chloride (\( \ce{CrO2Cl2} \)) in \( \ce{CS2} \), followed by hydrolysis; it is a method for aldehydes.
NCERT (2026-27 edition):
Carbylamine Reaction
