Using COC(=O)C(CC(F)(F)F)Nc1nc(-c2ccc(Br)cc2)cs1 to produce OCC(CC(F)(F)F)Nc1nc(-c2ccc(Br)cc2)cs1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.