Using O=C1CCC(=O)N1Br, Cc1ccc(N2C(=O)c3ccccc3C2=O)c(Cl)c1Cl to produce O=C1c2ccccc2C(=O)N1c1ccc(CBr)c(Cl)c1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.