Using O=C([O-])[O-], CC(C)(C)OC(=O)N1CCNC(C(O)(c2ccccc2)c2ccccc2)C1 to produce CC(C)(C)OC(=O)N1CCN2C(=O)OC(c3ccccc3)(c3ccccc3)C2C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.