Using COC(=O)c1ncnc(O)c1OC(=O)C(C)(C)C, COS(=O)(=O)OC to produce COC(=O)c1ncn(C)c(=O)c1OC(=O)C(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.