Using O=C(O)c1ccc2nc(-c3cc(C(=O)N4CCCC4)ccc3O)ccc2c1, CO to produce COC(=O)c1ccc2nc(-c3cc(C(=O)N4CCCC4)ccc3O)ccc2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.