In organic chemistry, the desulfonation reaction is the hydrolysis of sulfonic acids:[1] The reaction applied to aryl and naphthylsulfonic acids.
[2] The temperature of desulfonation correlates with the ease of the sulfonation.
This reactivity is exploited in the regiospecific preparation of many di- and tri-substituted aromatic compounds.
The approach exploits the meta-directing effect of the sulfonic acid group.
2-Chlorotoluene for example can be prepared by chlorination of p-toluenesulfonic acid, followed by hydrolysis.