Using COC(=O)CCC(=O)c1cc2c(s1)CCc1ccccc1C2=O to produce O=C(O)CCC(=O)c1cc2c(s1)CCc1ccccc1C2=O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.