Using Brc1cnc2nnn(Cc3ccc4ncccc4c3)c2n1, O=C(O)C1CCNC1 to produce O=C(O)C1CCN(c2cnc3nnn(Cc4ccc5ncccc5c4)c3n2)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.