Using O=C(O)CCl, CC(C)(C)OC(=O)N1C[C@H](Nc2ccc(Br)cc2[N+](=O)[O-])[C@@H](O)C1 to produce CC(C)(C)OC(=O)N1C[C@H](Nc2ccc(Br)cc2[N+](=O)[O-])[C@H](OC(=O)CCl)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.