Using OCC(Cl)(Cl)Cl, CC(=O)Oc1ccc2c(CC(=O)O)cc(=O)oc2c1 to produce CC(=O)Oc1ccc2c(CC(=O)OCC(Cl)(Cl)Cl)cc(=O)oc2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.