Using O=C([O-])[O-], CC(C)(C)c1cc(Br)c(C(=O)O)c(Br)c1O to produce COc1c(C(C)(C)C)cc(Br)c(C(=O)O)c1Br, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.