A rapid and convenient synthetic methodology for the cyclocondensative transformation of various alkylsulfanylphenylamines with bromoacetyl bromide by supporting on KF-alumina in ionic liquids [bmim][Br] and [bmim][BF4] has been developed to obtain 3-oxo-1,4-benzothiazine in good yields. The product is easily obtained by extraction with ethyl acetate and concentrating under vacuum. Easy recovery of ionic liquid and use in consecutive reactions is also reported.
