Using O=C1CCC(=O)N1Br, COc1ccc2c(c1)C(c1ccccc1)=CC2=O to produce COc1ccc2c(c1)C(c1ccccc1)=C(Br)C2=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.