Using O=C(OCc1ccccc1)C(CCSc1ccccc1)C(=O)OCc1ccccc1 to produce O=C(O)C(CCSc1ccccc1)C(=O)OCc1ccccc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.