Chapter 15, Problem 20P

Interpretation Introduction

Interpretation:

The major products that are formed when each of the given compound reacts with ${\text{Cl}}_2$ and ${\text{FeCl}}_3$ are to be predicted.

Concept introduction:

The common types of electrophilic substitution reaction of aromatic compounds are halogenation, nitration, sulfonation, Friedel–Craft alkylation, and acylation.

When an aromatic compound reacts with $C{l}_2$ in the presence of Lewis acid catalyst like $AlC{l}_3$, chlorination is carried out.

Para substitution is more stable over ortho due to steric hindrance at the ortho position.

Activating groups like alkyl groups gives substitution at the ortho and para position. Because they increase the electron densities at the ortho and para due to the delocalization of pi electrons of benzene ring. Ortho and para sites of the benzene ring is highly electron rich and thus electrophile usually attacks on these sites.

Deactivating group gives substitution at the meta position. Such electron withdrawing group gives stable product at meta position.