How do I get the chemical equation of aniline to phenylisocyanide?
1 Answer
Mar 2, 2014
The chemical equation is
C₆H₅-NH₂ + 3KOH + CHCl₃ → C₆H₅-NC + 3 KCl + 3H₂O
This is the carbylamine reaction. It is a test for primary amines, because the isocyanide has a foul smell. Secondary and tertiary amines do not give a positive test.
The mechanism involves the formation of dichlorocarbene, :CCl₂.
CHCl₃ + OH⁻ → H₂O + :C⁻Cl₃
:C⁻Cl₃ → :CCl₂ + Cl⁻
R-NH₂ + :CCl₂ → RN⁺H₂-C⁻Cl₂
RN⁺H₂-C⁻Cl₂ + OH⁻→ RNH-C⁻Cl₂ + H₂O
RNH-C⁻Cl₂ + OH⁻→ R-N=C⁻Cl + H₂O + Cl⁻
R-N=C⁻Cl → R-N≡C + Cl⁻
The net ionic equation is
R-NH₂ + CHCl₃ + 3OH⁻ → R-N≡C + 3H₂O + 3Cl⁻
