Chapter 23, Problem 23.15P

Interpretation Introduction

Interpretation:

The complete and detailed mechanism for the reaction is to be proposed.

Concept introduction:

When phenol is treated with bromine in water, it undergoes multiple brominations, even in the absence of a Lewis acid catalyst. Phenol is in equilibrium with a small amount of conjugate base, the phenoxide anion. Even though very little of the phenoxide anion is present, the O^- substituted is a very powerful activating group—far better than the OH group. So it dramatically increases the rate of electrophilic aromatic substitution. As a result, the phenoxide anion is the dominant reactant in the reaction.