2'-Hydroxychalcone (5a) reacted with pyridine perbromide, pyridine-bromine complex, and N-bromosuccinimide to form 3', 5'-dibromo-2'-hydroxychalcone (6a). Similarly, 2'-hydroxy-4- methoxychalcone (5b), 4-chloro-2'-hydroxychalcone (5c), and 2'-hydroxy-4-methoxy-5/- methylchalcone (5d) gave the corresponding nuclear brominated chalcones (6b-d). Authentic samples of 6, 8-dibromo-4'-methoxyflavone (4c), 8-bromo-4'-methoxy-6- ...