Using CCOC(=O)n1nc(O)c2ccc(C(=O)OC)cc21, O=C([O-])[O-] to produce CCOC(=O)n1nc(OC)c2ccc(C(=O)OC)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.