Using BrC(Br)(Br)Br, Cc1cccc(-c2c(C(C)O)oc(=O)c3ccccc23)c1 to produce Cc1cccc(-c2c(C(C)Br)oc(=O)c3ccccc23)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.