Using COC(=O)[C@@H]1CCCn2c(=O)c3ccccc3c(=O)n21 to produce O=C(O)[C@@H]1CCCn2c(=O)c3ccccc3c(=O)n21, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.