Using O=C([O-])O, COc1cc2nccc(Oc3ccc(SCCOc4ccc(Cl)cc4Cl)cc3)c2cc1OC to produce COc1cc2nccc(Oc3ccc(S(=O)CCOc4ccc(Cl)cc4Cl)cc3)c2cc1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.