Abstract: A mild procedure for trimethylsilyl group directed sulfonation through ipso aromatic substitution has been developed using in situ generated sulfur trioxide-dioxane complex. The process is effective with electron rich aromatic rings, but fails in the case of aromatic rings substituted by groups such as a carboxylate. Aromatic heterocycles form sulfur trioxide complexes which deactivate them to substitution. Key words: sulfur trioxide/dioxane ...
