The bromination of purines with a charge transfer complex between bromine and lutidine

Diaminopurines, immobilized on a polymeric support are treated with a charge transfer complex of bromine and lutidine to afford 8-brominated derivatives. An ionic complex of bromine and lutidine did not oxidize the purines. 2,6-Dialkylaminopurines could also be oxidized on the α-carbon of their 2-alkylamino group.