Question

Which amongst the following will give benzyl isocyanide as a major product? 

• A. i & ii
• B. ii & iii
• C. i & iii
• D. ii & iv

Answer 1

The Correct Option is A

Concept:
Isocyanides (\(-NC\)) are formed in two important reactions: \begin{itemize} \item Carbylamine reaction: Primary amines react with \(CHCl_3\) and \(NaOH\) to give isocyanides. \item Reaction with \(AgCN\): Alkyl halides react with silver cyanide to produce isocyanides due to covalent bonding in \(AgCN\). \end{itemize} Step 1: Reaction (i). Benzylamine reacts with \(CHCl_3/NaOH\): \[ C_6H_5CH_2NH_2 + CHCl_3 + NaOH \rightarrow C_6H_5CH_2NC \] This is the carbylamine reaction. Thus benzyl isocyanide is formed. Step 2: Reaction (ii). Benzyl bromide reacts with \(AgCN\): \[ C_6H_5CH_2Br + AgCN \rightarrow C_6H_5CH_2NC \] Thus benzyl isocyanide is formed. Step 3: Reaction (iii). Bromobenzene with \(AgCN\) does not react because aryl halides do not undergo nucleophilic substitution easily. Step 4: Reaction (iv). Aniline with \(CHCl_3/NaOH\) forms phenyl isocyanide rather than benzyl isocyanide. Step 5: Conclusion. Correct reactions producing benzyl isocyanide: \[ (i) \text{ and } (ii) \] \[ \boxed{\text{Option (1)}} \]