Tribromoisocyanuric Acid in Trifluoroacetic Acid: An Efficient System for Smooth Brominating of Moderately Deactivated Arenes

Moderately deactivated arenes are efficiently brominated by the reaction with tribromoisocyanuric acid (0.34 mol equiv) in trifluoroacetic acid at room temperature in 48–85% isolated yield. This medium avoids the polybromination of the substrate, ­observed in the same reaction performed in 98% H 2 SO 4 .