Using COC(=O)c1cc2c(ncn2C)c(Cl)c1Nc1ccc(Br)cc1Cl to produce Cn1cnc2c(Cl)c(Nc3ccc(Br)cc3Cl)c(C(=O)O)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.