Using Nc1nc2c3ccc(C(=O)O)cc3nc(Cc3ccc4c(c3)OCO4)n2n1, NCCO to produce Nc1nc2c3ccc(C(=O)NCCO)cc3nc(Cc3ccc4c(c3)OCO4)n2n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.