Using O=C(Br)CBr, CC(C)(C)OC(=O)N1CCN(c2cc(N)ncn2)CC1 to produce CC(C)(C)OC(=O)N1CCN(C(=O)CBr)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.