Which of the following reagents does not reduce nitrobenzene ( C ₆ H ₅ NO ₂ ) to aniline?

Step-by-step solution

Reduction of nitrobenzene with metals in acidic medium such as Sn / HCl , SnCl ₂ / HCl , or Zn / HCl yields aniline. However, when nitrobenzene is reduced with lithium aluminium hydride ( LiAlH ₄ ), it undergoes a bimolecular reduction to form azobenzene ( C ₆ H ₅- N = N - C ₆ H ₅ ), not aniline. Note that LiAlH ₄ reduces aliphatic nitro compounds to primary amines, but it couples aromatic nitro compounds to form azo compounds. Therefore, LiAlH ₄ does not reduce nitrobenzene to aniline. Answer: LiAlH ₄