Using COC(=O)c1nc2c(s1)CCOc1ccc(Br)cc1-2, O=C1CCC(=O)N1Br to produce COC(=O)c1nc2c(s1)C(Br)COc1ccc(Br)cc1-2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.