Three-Component Synthesis of 3-(Arylsulfonyl)benzothiophenes Using Acetic Acid as a Quencher for Methyl Radical-Mediated Side Reactions

A one-pot, three-component synthesis of 3-(arylsulfonyl)benzothiophenes was developed. The reaction did not require any catalysts or additives. The desired products were obtained via an intramolecular radical cyclization. Acetic acid was employed as the solvent and a quencher for side reactions involving methyl radicals. Moreover, inexpensive potassium metabisulfite was used as a sulfur dioxide surrogate. This process provides more opportunities for synthesizing benzothiophene derivatives, which are found in many bioactive compounds. (Figure presented.).