Using CCN(CC)S(F)(F)F, O=C1COCC(CO)(c2cc(Br)cnc2Cl)N1 to produce O=C1COCC(CF)(c2cc(Br)cnc2Cl)N1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.