Treatment of N-aryl-2-(benzylthio)benzamides with phenyliodine(III) bis(trifluoroacetate) containing trifluoroacetic acid resulted in an interrupted Pummerer-type reaction in ionicliquid 1-n-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF 6 ] to give 2-aryl-1,2-benzisothiazol-3(2H)-ones rather than the normal Pummerer-type products.