Question

Chlorobenzene can be prepared by reacting aniline with :

• A. hydrochloric acid
• B. cuprous chloride
• C. chlorine in presence of anhydrous aluminium chloride
• D. nitrous acid followed by heating with cuprous chloride

Answer 1

The correct option is D nitrous acid followed by heating with cuprous chloride

When aniline is treated with nitrous acid, which is produced in situ by sodium nitrite and hydrochloric acid, at low temperature $(0^{\circ }C-5^{\circ }C)$, then aniline is converted to a benzene diazonium salt. This reaction is known as diazotization. Hence, the correct answer is option (d).

$C_6{H}_{5}N{H}_2\underset{0^{\circ }C-5^{\circ }C}{\overset{NaN{O}_2/HCl}{\to }}{C}_6{H}_5{N}_{2}Cl\stackrel{CuCl}{\to }{C}_6{H}_{5}Cl$