Question

Which of the following set(s) of reagents convert benzoic acid (\(X\)) to primary amine (\(Y\)) with one carbon atom more than that in \(X\)? \[ \begin{aligned} \text{I. }&\mathrm{NH_3/\Delta;\ Br_2,\ OH^-} \text{II. }&\mathrm{LiAlH_4;\ H_2O} \text{III. }&\mathrm{LiAlH_4,\ H_2O;\ NaBr/H_2SO_4;\ KCN;\ H_2/Ni} \end{aligned} \] The correct answer is

• A. I, II only
• B. II, III only
• C. III only
• D. II only

Hint:

To increase the carbon chain by one and obtain a primary amine: \[ \boxed{ \mathrm{R{-}X} \xrightarrow{\mathrm{KCN}} \mathrm{R{-}CN} \xrightarrow{\mathrm{H_2/Ni}} \mathrm{R{-}CH_2NH_2} } \] The cyanide ion contributes one additional carbon atom.

Answer 1

The Correct Option is C