Question

Which of the following substituents is a moderate activator and an o/p director in electrophilic aromatic substitution reactions?
A) -Br
B) -SO3H
C) -CO2H
D) -NHCOR
E) -CHO

Answer 1

Answer:

NHCOR

Explanation:

In electrophilic aromatic substitution, certain substituents on the aromatic ring such as

-NHCOR are known to enhance ortho-para substitution. These ortho-para activating groups stabilizes the intermediate cation.

These ortho-para activating groups usually consists of species that donate electron density towards the reaction centre thereby stabilizing the carbocation and making the reaction faster.