Using COC(=O)CC1CN(CC(=O)NCCCCNc2ccccn2)CCc2ccccc21 to produce O=C(O)CC1CN(CC(=O)NCCCCNc2ccccn2)CCc2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.