Using CCCOC(=O)c1sc(C(=O)OCCC)c(O)c1C, O=S(=O)(Cl)c1ccc(Br)cc1 to produce CCCOC(=O)c1sc(C(=O)OCCC)c(OS(=O)(=O)c2ccc(Br)cc2)c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.