Using CCOC(=O)C1Oc2cc(C(=O)c3ccnn3C)c(Cl)c(Cl)c2O1, [O-][Br+2]([O-])[O-] to produce CCOC(=O)C1Oc2cc(C(=O)c3c(Br)cnn3C)c(Cl)c(Cl)c2O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.