Using O=[N+]([O-])c1cccc2c1sc1c(Nc3cccc(Br)c3)ncnc12 to produce Nc1cccc2c1sc1c(Nc3cccc(Br)c3)ncnc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.