Using CC(=O)N1C2CN3OC(O)(C(COC(N)=O)c4c(O)cc(C=O)cc43)C21, O=C([O-])[O-] to produce COc1cc(C=O)cc2c1C(COC(N)=O)C1(O)ON2CC2C1N2C(C)=O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.