Question

Which of the following compounds will undergo Friedel-Crafts alkylation with faster rate?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

More the $EDG$, faster is the $SE$ reaction or $F.C$. reaction. But $ED$ power of $\left(-N{H}_2\right)$ (by resonance) is greater than $\left(-C{H}_3\right)$ (by hyperconjugation). But aniline does not undergo $F.C$. reaction.
Therefore, in (1), three $H.C$. structures.
In (3), one $H.C$. structure.
In (4), $\left(-N{O}_2\right),EWG,F.C$. reaction does not take place.
So in (2), $F.C$. reaction is fastest.