Using COC(=O)C1c2cccc(Br)c2CCN1C(=O)OC(C)(C)C to produce CC(C)(C)OC(=O)N1CCc2c(Br)cccc2C1C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.