Using CCOC(=O)Cc1c(C(=O)OCC)cc(C(=O)c2ccc(Cl)cc2)n1C, BrBr to produce CCOC(=O)Cc1c(C(=O)OCC)c(Br)c(C(=O)c2ccc(Cl)cc2)n1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.