Chapter 23, Problem 23.45P

Interpretation Introduction

Interpretation:

Alkyl groups are activating, so both of the trisubstituted benzenes shown undergo chlorination much faster than benzene. The 1, 2, 3-trisubstituted compound, however, undergoes chlorination faster than the 1, 2, 4-trisubstituted compound. The reason for it is to be explained.

Concept introduction:

The electron donating groups activates whereas the electron withdrawing groups deactivates the aromatic ring. The electron donating groups are ortho-para directing, which means electrophilic aromatic substitution preferably occurs at ortho-para position.