Using O=C([O-])[O-], CCOc1ccc([N+](=O)[O-])c(C(=O)O)n1 to produce CCOc1ccc([N+](=O)[O-])c(C(=O)OC)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.