Using O=C(O)Cc1ccc(Br)cc1, O=Cc1ccc(Cl)cc1[N+](=O)[O-] to produce O=C(O)/C(=C/c1ccc(Cl)cc1[N+](=O)[O-])c1ccc(Br)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.