Using O=C(c1ccc2ccc3ncc(Cl)cc3c(=O)c2c1)C(F)F to produce OC1c2cc(C(O)C(F)F)ccc2C=Cc2ncc(Cl)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.