Facial Syntheses of Bromobenzothiazines via Catalyst-Free Tandem C–H Amination/Bromination in Water

A transition-metal-free and environmentally friendly synthesis method for bromobenzothiazines through tandem C–H amination/bromination was reported. This reaction contains both intramolecular C–H amination and site-selective electrophilic bromination of arenes with NaBr as the bromo source, PhI(OAc)2 or K2S2O8 as the oxidant, and H2O as the only solvent.