Using NC(=O)CCC(=O)NBr, Cc1c(Br)cnc([N+](=O)[O-])c1Br to produce O=[N+]([O-])c1ncc(Br)c(CBr)c1Br, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.