Using O=C([O-])[O-], COc1cc(OC)c([N+](=O)[O-])cc1C(=O)O to produce COC(=O)c1cc([N+](=O)[O-])c(OC)cc1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.