Using Cc1ccc(S(C)(=O)=O)c(S(=O)(=O)NC(C)(C)C)c1, O=C1CCC(=O)N1Br to produce CC(C)(C)NS(=O)(=O)c1cc(CBr)ccc1S(C)(=O)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.