With optimized reagents and conditions in hand for halogenation, a broad screen of both building blocks and pharmaceutically relevant substances was pursued as illustrated in Table . In nearly all cases, a dramatic increase in yield was observed for chlorination and bromination relative to either literature results or comparison to in-house results using Palau'chlor or NBS. Thus, heterocycles such as 1,2,4-triazoles (13, 14, 33), pyridine , pyrazoles , indazole (17), thiazole , quinoline , pyrimidine (29-31), thiophene (36), imidazole (43), others as well as multisubstituted phenyl rings can all be cleanly halogenated. [filtration]