A Convenient Synthesis of 1,4-Benzothiazepines from 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed 1,3-Benzothiazine Derivatives - Fodor, Lajos; Csomós, Péter; Csámpai, Antal; Sohár, Pál (Synthesis, 2010)