Using CC(=O)O, COC(=O)CC(Cn1cnc2c1N=CNC2N)C(=O)OC to produce O=C(O)CC(Cn1cnc2c(=O)[nH]cnc21)C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.