A new approach to the synthesis of imine containing 1, 2, 5-benzothiadiazepine-1, 1- dioxides and 1, 4-benzodiazepin-5-ones using iminophosphoranyl thiazine-S-oxides as precursors is reported. Key steps include a Staudinger reaction, an aza-Wittig reaction and the conversion of a thiazine-S-oxide into an amino ketone via a [2, 3] sigmatropic rearrangement.
