Chapter 23, Problem 23.62P

Interpretation Introduction

Interpretation:

Electrophilic aromatic substitution on a monosubstituted naphthalene tends to take place on the same ring as the substituent when the substituent is an activator like ${\text{CH}}_{\text{3}}$, and tends to take place on the unsubstituted ring when the substituent is a deactivator like ${\text{NO}}_{\text{2}}$. The reason for it is to be explained.

Concept introduction:

Aromatic rings other than benzene can also undergo electrophilic aromatic substitution including naphthalene, furan, pyrrole, and pyridine. Naphthalene is considered to be activated toward electrophilic aromatic substitution. In electrophilic aromatic substitution, the ring acts as a nucleophile, thus if the ring has electron-donating group, it has more electron density and it will be more reactive toward electrophiles. Also if the ring has electron-withdrawing group, the other ring is more electron-rich and so it is more reactive toward electrophiles.