Using COc1ccc(Oc2ccc(C(=O)C(=O)c3ccc(Oc4ccc(OC)cc4)cc3)cc2)cc1 to produce O=C(C(=O)c1ccc(Oc2ccc(O)cc2)cc1)c1ccc(Oc2ccc(O)cc2)cc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.