Using O=[N+]([O-])[O-], CCc1cc2c(cc1CC)=NC(=O)C(=O)N=2 to produce CCc1cc2[nH]c(=O)c(=O)[nH]c2c([N+](=O)[O-])c1CC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.