Using O=C(Nc1nccs1)C(CC1CCCC1O)c1ccc(Cl)c(Cl)c1 to produce O=C1CCCC1CC(C(=O)Nc1nccs1)c1ccc(Cl)c(Cl)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.