Using [Br-], COc1cc(N2CCC(O)(CCOS(=O)(=O)c3ccccc3)CC2)c(Cl)cc1Cl to produce COc1cc(N2CCC(O)(CCBr)CC2)c(Cl)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.