Using C[C@H](Nc1ncnc2[nH]cnc12)c1nc2ccccc2n1[C@@H]1CCCNC1, CC(C)(O)C(=O)O to produce C[C@H](Nc1ncnc2[nH]cnc12)c1nc2ccccc2n1[C@@H]1CCCN(C(=O)C(C)(C)O)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.