Benzodiazines synthesis

The parent system (28, R=H) is commercially produced by a modified Hofmann degradation of phthaUmide. It can be used as a building block in benzodiazine synthesis (for an example, cf. p. 496). 

In 1995-2006, synthesis of benzothiazines by ttansformation of another ring was also another common approach, similar to the previous review in CHEC-II(19%) <1996CHEC-II(6)637>. The dihydrogenated benzodiazine 5 -oxide 32 was synthesized successfully by a two step reaction. Compound 32 was obtained in 81% yield by treatment of 31 with... 

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