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. Lewisacids - catalysis - 2,2-dimethylthiirane - 2-(aryl-amino)ethanethiols - aminolysis