Using COc1ccc(C(=O)c2cccc(C(=O)c3ccc(OC)cc3)c2)cc1 to produce COc1ccc(C(=O)c2cccc(C(=O)c3ccc(O)cc3)c2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.