Using COC(=O)C(O)c1cc(C(F)(F)F)cc(C(F)(F)F)c1, BrC(Br)(Br)Br to produce COC(=O)C(Br)c1cc(C(F)(F)F)cc(C(F)(F)F)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.