Using COC(=O)CCc1csc(Nc2ncc(Br)cc2Oc2ccccc2)n1 to produce O=C(O)CCc1csc(Nc2ncc(Br)cc2Oc2ccccc2)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.