Using CCOC(=O)c1cn(Nc2c(Cl)cc(Cl)cc2Cl)c(=O)[nH]c1=O to produce O=C(O)c1cn(Nc2c(Cl)cc(Cl)cc2Cl)c(=O)[nH]c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.