A microwave induced cyclisation of α‐phenylsulfonyl‐enaminoacrylates for the preparation of 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives

Several 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives have been prepared in good yields by microwave promoted cyclisation of α‐phenylsulfonyl‐enaminoacrylate intermediates in basic media. Benzothiazines were obtained without the use of a catalyst in short reaction times.