Using O=N[O-], COc1ccc2c(c1)C[C@@H](C)N2C(C)=O to produce COc1cc2c(cc1[N+](=O)[O-])N(C(C)=O)[C@H](C)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.