Using O=C(Cl)c1c(F)cc(F)cc1F, O=C(O)c1ccc[nH]1 to produce O=C(O)c1cc(C(=O)c2c(F)cc(F)cc2F)c[nH]1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.