Using BrC(Br)(Br)Br, COC(=O)[C@@H]1C[C@@H](O)CN1C(=O)OC(C)(C)C to produce COC(=O)[C@@H]1C[C@H](Br)CN1C(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.