Chapter 23, Problem 23.13P

Interpretation Introduction

Interpretation:

The reason for the given synthesis is to be explained.

Concept introduction:

Treating benzene with concentrated sulfuric acid yields benzenesulfonic acid, whereby a sulfo group, ${\text{SO}}_{\text{3}}\text{H}$, has been incorporated onto the ring. This kind of substitution reaction is called sulfonation. Sulfonation can be slow because the concentration of the ${\text{HSO}}_{\text{3}}{}^{\text{+}}$ electrophile in concentrated ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ is rather small. Sulfonation can be sped up, however, using fuming sulfuric acid, which is concentrated sulfuric acid infused with ${\text{SO}}_{\text{3}}$. Under these acidic conditions, ${\text{SO}}_{\text{3}}$ is protonated to produce ${\text{HSO}}_{\text{3}}{}^{\text{+}}$.