Question

Which of the following gives $RNC$ when treated with $CHCl_{3}$ and $KOH$?

• A. $RNH_{2}$
• B. $R_{2}NH$
• C. $R_{4}N^{+}Cl^{-}$
• D. $R_{3}N$

Answer 1

Answer: (A)

$RNH_{2}$

Answer 2

Only primary amines, when treated with chloroform and alkali $( KOH )$, gives isocyanide (RNC), the bad smelling compound. This reaction is called carbylamine reaction. Among the given amines, $R NH _{2}$ is a primary amine, so forms RNC when treated with $CHCl _{3}$ and $KOH$.
$RNH _{2}+ CHCl _{3}+3 KOH$
$\longrightarrow \underset{\text{alkyl iso-cyanide}}{R N C}+3 KCl +3 H _{2} O$