The compound from which chlorobenzene cannot be prepared easily is

Step-by-step solution

Chlorobenzene can be easily prepared from aniline by first converting it to benzene diazonium chloride, followed by the Sandmeyer reaction. Chlorobenzene can be easily prepared from benzene by electrophilic aromatic substitution using Cl₂ in the presence of a Lewis acid catalyst like FeCl₃ or AlCl₃ . Chlorobenzene can be easily prepared from benzene diazonium chloride by treating it with Cu₂Cl₂ and HCl (Sandmeyer reaction). In phenol, the carbon-oxygen bond acquires a partial double bond character due to resonance