Using Oc1cc(-c2ccc(Br)s2)n(-c2ccccc2Cl)n1, COC(=O)CBr to produce COC(=O)COc1cc(-c2ccc(Br)s2)n(-c2ccccc2Cl)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.