Using CC(C)(C)OC(=O)CNC(=O)OC(C)(C)C, COC(=O)c1ccc(CBr)cc1 to produce COC(=O)c1ccc(CC(NC(=O)OC(C)(C)C)C(=O)OC(C)(C)C)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.