Using O=[N+]([O-])c1ccc(OCc2nnc(Nc3ccc(Cl)c(Cl)c3)o2)cc1 to produce Nc1ccc(OCc2nnc(Nc3ccc(Cl)c(Cl)c3)o2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.