NaClO2-mediated preparation of pyridine-2-sulfonyl chlorides and synthesis of chiral sulfonamides

A simple method to prepare azaarenesulfonyl chlorides by NaClO2-mediated oxidative chlorination of azaarenethiols have been developed, with water as the solvent. Easy purification by simple extraction and concentration gives the products in good yields. The azaarenesulfonyl chlorides readily undergo condensation with chiral amines to afford chiral sulfonamides.