Using O=C1CCC(=O)N1Br, CC(=O)Oc1cc(C)ccc1CC(=O)OC(C)(C)C to produce CC(=O)Oc1cc(CBr)ccc1CC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.