Using O=C(O)c1ccc(N2CCN(C(=O)c3ccccc3)CC2)cc1[N+](=O)[O-] to produce Nc1cc(N2CCN(C(=O)c3ccccc3)CC2)ccc1C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.