Using O=C([O-])O, O=C(O)CN1C(=O)c2cc(Cl)c(Cl)cc2C1=O to produce COC(=O)CN1C(=O)c2cc(Cl)c(Cl)cc2C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.