Using COC(=O)c1cc(O)cc(C(=O)OC)c1, OCCc1ccc(Cl)cc1Cl to produce COC(=O)c1cc(OCCc2ccc(Cl)cc2Cl)cc(C(=O)OC)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.