Using CCOC(=O)COc1ccc2nc3c4ccccc4c(=O)n(-c4ccc([N+](=O)[O-])cc4)c3n2c1 to produce O=C(O)COc1ccc2nc3c4ccccc4c(=O)n(-c4ccc([N+](=O)[O-])cc4)c3n2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.