Which of the following reactions can produce aniline as main product?

• A

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2+\mathrm{Zn} / \mathrm{KOH}$
• B

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2+\mathrm{Zn} / \mathrm{NH}_4 \mathrm{Cl}$
• C

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2+\mathrm{LiAlH}_4$
• Correct answer
  D

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2+\mathrm{Zn} / \mathrm{HCl}$

Solution

Various products are formed when nitroarenes are reduced. These are given below for $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2$. $$ \text { Medium } \quad \text { Main product } $$ (d) In acidic medium Aniline $\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2\right)$ $(\mathrm{metal} / \mathrm{HCl})$ (b) In neutral medium Phenyl hydroxylamine, $\left(\mathrm{Zn} / \mathrm{NH}_4 \mathrm{Cl}\right)$
$$ \text { (a) In alkaline medium } $$
Thus, aniline will be main product in case of (d).

Hence, the correct answer is option: 'D'.