Synthesis of 2-(Arylamino)ethanethiols via Lewis Acid Catalyzed Aminolysis of 2,2-Dimethylthiirane as Precursors of the 1,4-Benzothiazine Nucleus

Ring opening of2,2-dimethylthiirane by deactivated aromatic amines to afford 2-(arylamino)ethanethiols as 6-substituted 1,4-benzothiazine precursors, was investigated. The reaction takes place under mild conditions using copper(II) triflate or indium(III) triflate as catalysts. The regioselectivity of the addition depends on the catalysts and the substituents of the arylamines.