Using OCc1cc(Cl)cc(Cl)c1, COC(=O)c1cccc(O)c1C(=O)OC to produce COC(=O)c1cccc(OCc2cc(Cl)cc(Cl)c2)c1C(=O)OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.