Question

Identify B in the following reaction
\[ R{-}C \equiv N \xrightarrow[\text{dil. HCl}]{SnCl_2} A \xrightarrow{H_3O^+} B + NH_4Cl \]

• A. $R{-}COOH$
• B. $R{-}CONH_2$
• C. $R{-}CHO$
• D. $RCH_2NH_2$

Hint:

Stephen reduction converts nitriles into aldehydes using $SnCl_2$/HCl followed by hydrolysis.

Answer 1

The Correct Option is C

Step 1: Identify the reaction type.
The given reaction is Stephen reduction, where a nitrile is reduced to an aldehyde using $SnCl_2$ and dilute HCl.
Step 2: Formation of intermediate A.
The nitrile first forms an iminium salt intermediate.
Step 3: Hydrolysis of intermediate.
On hydrolysis with $H_3O^+$, the iminium salt is converted into an aldehyde.
Step 4: Conclusion.
The final product B formed is an aldehyde, $R{-}CHO$.