Using CS(=O)(=O)CCO, CCOC(=O)C1=Cc2c(ccc(Cl)c2F)OC1C(F)(F)F to produce O=C(O)C1=Cc2c(ccc(Cl)c2O)OC1C(F)(F)F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.