Using O=C1CCC(=O)N1Br, Cn1c(COc2ccc(Cl)cc2)cc2ccccc21 to produce Cn1c(COc2ccc(Cl)cc2)c(Br)c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.