Using CC(C)(C)OC(=O)CC(=O)c1cnc(NC(=O)C(C)(C)C)cn1, O=C1CCC(=O)N1Br to produce CC(C)(C)OC(=O)C(Br)C(=O)c1cnc(NC(=O)C(C)(C)C)cn1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.