Naphtho thiazine dioxides

Both Trummlitz et al.126 and Steiner127 appear independently to have prepared naphtho [2,1-e]-1,2-thiazine analogs of the potent oxicam antiinflammatory agents by the reaction sequence of Scheme 4. 3-Oxonaphth-[2,1 -d] isothiazoline-2-acetic ester 1,1-dioxides (147) (R = Me or Et) were... 

Trummlitz and co-workers126 also prepared derivatives of 150 by treatment of 2-methyl-2H-naphtho [2,1-c] [l,2]thiazin-4-(3H)-one 1,1-dioxide (151) with sodium hydride and an aryl isocyanate. The starting material (151) for this sequence was synthesized analogously to the related benzo-thiazine 11. 

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