Using CC[C@H](C)[C@H](NC(=O)OC)C(=O)N1[C@@H](C)CC[C@H]1C(=O)O, O=C(CBr)c1ccc2c(c1)COc1cc3c(cc1-2)CCC(Br)C3=O to produce CC[C@H](C)[C@H](NC(=O)OC)C(=O)N1[C@@H](C)CC[C@H]1C(=O)OCC(=O)c1ccc2c(c1)COc1cc3c(cc1-2)CCC(Br)C3=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.