Using CCOC(=O)c1cc2c(n1S(=O)(=O)c1ccc(Cl)c(Cl)c1)CCCC2 to produce O=C(O)c1cc2c(n1S(=O)(=O)c1ccc(Cl)c(Cl)c1)CCCC2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.