Using [Br-], CN(C(=O)CC(CCOS(C)(=O)=O)c1ccc(Cl)c(Cl)c1)c1ccc(Cl)cc1 to produce CN(C(=O)CC(CCBr)c1ccc(Cl)c(Cl)c1)c1ccc(Cl)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.