Using CC(C)(C)OC(=O)N1CCN(C(=O)OC(C)(C)C)C2C(=O)N(Cc3ccccc3)C(=O)C21 to produce O=C1C2NCCNC2C(=O)N1Cc1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.