Using CCOC(=O)c1cc(Br)cc2c(C3CCS(=O)(=O)C(C)(C)C3)cn(C(=O)OC(C)(C)C)c12 to produce CC1(C)CC(c2c[nH]c3c(C(=O)O)cc(Br)cc23)CCS1(=O)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.