Carbylamine reaction
Aliphatic and aromatic primary amines on heating with chloroform and alcoholic KOH give isocyanides (carbylamines) with a foul smell.
EthanamineCH₃CH₂NH₂Amine - Step 1
CHCl₃ + alc. KOH, heat
Ethyl isocyanideCH₃CH₂NCCompound
How it works
- Chloroform and base give dichlorocarbene.
- The amine nitrogen attacks the carbene.
- Elimination of HCl gives the isocyanide.
What it makes
Isocyanides; also a test for primary amines.
Where it fails
Secondary and tertiary amines do not respond.
Class 12, Chapter 9 Amines
Carbylamine reaction: quick answers
Which amines respond?
Only primary amines, aliphatic or aromatic.
What is formed from aniline?
Phenyl isocyanide.
What tells you the reaction has worked?
A very bad, characteristic smell.