Using BrC(Br)(Br)Br, CCOc1ccc([N+](=O)[O-])c(C=O)c1 to produce CCOc1ccc([N+](=O)[O-])c(C=C(Br)Br)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.