Using O=C(O)C1=Cc2ccc(C3CC3)cc2OC1C(F)(F)F, ClCl to produce O=C(O)C1=Cc2cc(Cl)c(C3CC3)cc2OC1C(F)(F)F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.