Using [Br-], CCS(=O)(=O)N1CCN(c2cnc(N)c(C(C)=O)n2)CC1 to produce CCS(=O)(=O)N1CCN(c2cnc(N)c(C(=O)CBr)n2)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.