Using O=S([O-])O, COC(=O)c1ccc2c(N=O)c(O)ccc2c1 to produce COC(=O)c1ccc2c(N)c(O)cc(S(=O)(=O)O)c2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.