Using O=C1CCC(=O)N1Br, Cc1nc(-c2ccc(Cl)cc2)sc1C(=O)O to produce O=C(O)c1sc(-c2ccc(Cl)cc2)nc1CBr, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.