Using CSc1ncnc2c(N3CCOCC3)nc(N3CCN(C=O)CC3)nc12 to produce CSc1ncnc2c(N3CCOCC3)nc(N3CCNCC3)nc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.