Using O=C(Cl)C1(CCCCBr)c2ccccc2-c2ccccc21, NCC(F)(F)F to produce O=C(NCC(F)(F)F)C1(CCCCBr)c2ccccc2-c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.