Using CC1(C)CC(=O)CC(=O)C1, O=C(CBr)c1cccc(Br)c1 to produce CC1(C)CC(=O)C(CC(=O)c2cccc(Br)c2)C(=O)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.