Stereoselective Synthesis of 4-Aminobenzo[c][1,2]thiazine via Modification of the Harmata Benzothiazine Synthesis.

A stereoselective synthesis of 4-aminobenzothiazines was developed through a modified Harmata benzothiazine synthesis. The reaction has very good substrate scope and good functional group tolerance was observed. The products were obtained with high enantiomeric purity. Many interesting heterocyclic analogues were made using this methodology.