Question: 76: Which of the following sequence of reactions is suitable to synthesize chlorobenzene?
Answer: Option (3)
Explanation:
Chlorobenzene is prepared by electrophilic aromatic substitution of benzene with chlorine in the presence of a Lewis acid catalyst.
In option (3), benzene reacts with chlorine in the presence of anhydrous \mathrm{FeCl}_{3},
which acts as a catalyst to generate the electrophile \mathrm{Cl}^{+}.
This electrophile substitutes a hydrogen atom on the benzene ring to form chlorobenzene.
Benzene does not react directly with HCl, so option (1) is incorrect.
Aniline reacts with HCl to form anilinium chloride, and heating does not produce chlorobenzene,
so option (2) is incorrect.
Phenol reacting with \mathrm{NaNO}_{2}, HCl, and CuCl involves diazotisation reactions,
which do not directly synthesize chlorobenzene from phenol, so option (4) is incorrect.
Therefore, the correct sequence of reactions to synthesize chlorobenzene is given in option (3).