Using OO, COc1ccc(Cc2c(C)c(OC)c(OC)c(OC)c2OC)cc1C=O to produce COc1ccc(Cc2c(C)c(OC)c(OC)c(OC)c2OC)cc1C(=O)O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.