Using COc1ccc(Br)c(C(=O)N2CCN(C(=O)CNC(=O)OC(C)(C)C)CC2)c1 to produce COc1ccc(Br)c(C(=O)N2CCN(C(=O)CN)CC2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.