Mechanism of the Carbylamine Reaction

The mechanism of the Carbylamine Reaction involves several steps:

1. Chloroform (CHCl₃) is deprotonated by the base (KOH), forming the trichloromethide anion (CCl₃^-).
2. The trichloromethide anion then loses a chloride ion (Cl^-) to form dichlorocarbene (:CCl₂), which is highly reactive.
3. Dichlorocarbene reacts with the primary amine (R-NH₂) to form an intermediate (R-NH-CCl₂).
4. This intermediate undergoes dehydrochlorination, losing two molecules of HCl, to form the isocyanide (R-NC).

The overall process can be summarized as:

R-NH₂ + CHCl₃ + 3KOH → R-NC + 3KCl + 3H₂O

This reaction is specific for primary amines and is used as a qualitative test to identify them.