Identify the final product formed when benzenamine reacts with the given reagents in the sequential order as: i. (CH₃- CO )₂ O / Pyridine. ii. Conc. HNO₃ + H₂ SO₄ & then reacted with H₃ O ^+ iii. NaNO₂ HCl (273K) & then reacted with H₃ PO₂ (aq).

Step-by-step solution

Benzenamine (aniline) reacts with acetic anhydride in the presence of pyridine to form acetanilide. This step protects the amino group and prevents polysubstitution and oxidation. Acetanilide undergoes nitration with a mixture of concentrated HNO ₃ and concentrated H ₂ SO ₄ to form p -nitroacetanilide as the major product due to steric hindrance at the ortho position. Hydrolysis of p -nitroacetanilide with H ₃ O ^+ removes the acetyl group, yielding p -nitroaniline. p -Nitroaniline reacts with NaNO ₂ and HCl at 273