Question

Which of the following gives $RNC$ when treated with $CHC{l}_3$ and $KOH$?

• A. $RN{H}_2$
• B. $R_{2}NH$
• C. $R_4{N}^{+}C{l}^{-}$
• D. $R_{3}N$

Answer 1

Answer: (A)

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, $RN{H}_2$ is a primary amine, so forms RNC when treated with $CHC{l}_3$ and $KOH$.
$RN{H}_2+CHC{l}_3+3KOH$
$⟶\underset{\text{alkyl iso-cyanide}}{\mathrm{RNC}}+3KCl+3H_{2}O$