Using COc1ccc(C(=Cc2ccc(OC)c(OC)c2)C(=O)O)cc1, O=C([O-])[O-] to produce COC(=O)C(=Cc1ccc(OC)c(OC)c1)c1ccc(OC)cc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.