Using COc1cc(C(=O)c2ncc3c(O)cccn23)ccc1N, O=C([O-])[O-] to produce COc1cc(C(=O)c2ncc3c(OC)cccn23)ccc1N, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.