Using CC(=O)OCc1cc(Cl)cc(Cl)c1CC(=O)NC1COc2ncccc21 to produce O=C(Cc1c(Cl)cc(Cl)cc1CO)NC1COc2ncccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.