Using O=[N+]([O-])O, CC(=O)c1c[nH]c(-c2ccncc2)c1C to produce CC(=O)c1c([N+](=O)[O-])[nH]c(-c2ccncc2)c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.