Using CCOC(=O)c1cc(C(=O)c2ccccc2)c2ccccn2c1=O to produce O=C(O)c1cc(C(=O)c2ccccc2)c2ccccn2c1=O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.