Using C1CCNC1, CCOC(=O)C(C)(C)N1CCN(C(=O)OC(C)(C)C)CC1 to produce CC(C)(C)OC(=O)N1CCN(C(C)(C)C(=O)N2CCCC2)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.