Using OCCO, NS(=O)(=O)c1cc(C(=O)O)c(NCc2ccco2)cc1Cl to produce NS(=O)(=O)c1cc(C(=O)OCCO)c(NCc2ccco2)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.