Using O=C(COc1ccc(Cl)cc1)COc1ccc(CCC(=O)OCc2ccccc2)cc1 to produce O=C(O)CCc1ccc(OCC(=O)COc2ccc(Cl)cc2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.