Question

Which of the following group is the strongest ring activator towards electrophilic aromatic substitution?

• A. -OH
• B. -NH2
• C. -OCH3
• D. -Cl

Answer 1

Answer: (B)

-NH2

Answer 2

The substituent $-NH_2$ is the strongest activator among the given groups because it donates electrons via resonance very effectively, increasing the electron density on the aromatic ring and thereby greatly enhancing the rate of electrophilic aromatic substitution.

The group $-Cl$ is deactivating, while $-OH$ and $-OCH_3$ are activating but less strongly compared to $-NH_2$.