Using O=C([O-])O, COC(OC)(c1ccc(Sc2ccccc2)c(CC(=O)[O-])c1)C(C)Br to produce CC(C(=O)O)c1ccc(Sc2ccccc2)c(CC(=O)O)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.