Using O=C([O-])[O-], Cc1ccc([N+](=O)[O-])cc1S(=O)(=O)O to produce O=C(O)c1c([N+](=O)[O-])cccc1S(=O)(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.