Using O=C1CCC(=O)N1Br, Clc1ccc2c(c1)Cc1cc(Cl)ccc1OCO2 to produce Clc1ccc2c(c1)C(Br)c1cc(Cl)ccc1OCO2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.