CBSE Class 12 · 2001 · Delhi · Compounds Containing NitrogenShort Answer

Before reacting aniline with HNO₃ for nitration, it is converted to acetanilide. Why is this done, and how is nitroaniline obtained subsequently?

Solution

Aniline itself is partly protonated by the nitrating acid (the anilinium ion is m-directing) and is easily oxidised by HNO

_{3}

— a tarry mixture results.
Acetylation tames the ring:

C_{6} H_{5} N H_{2} (C H_{3} CO)_{2} O C_{6} H_{5} NHCOC H_{3} HN O_{3} / H_{2} S O_{4}, 288K p - O_{2} N - C_{6} H_{4} - NHCOC H_{3}

Hydrolysis then frees the amine:

p - O_{2} N C_{6} H_{4} NHCOC H_{3} H_{3} O^{+} or O H^{-}, Δ p - O_{2} N C_{6} H_{4} N H_{2}

CBSE Class 12 Board · 2001 · Delhi · Subjective