Using NC(=O)Cc1ccc2[nH]cc(CCN3C(=O)c4ccccc4C3=O)c2c1, O to produce NC(=O)Cc1ccc2[nH]cc(CCNC(=O)OCc3ccccc3)c2c1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.