tert-Butyl 5-Bromoisoindoline-2-carboxylate is an intermediate used in the synthesis of Isothiazoloquinolones with Enhanced Antistaphylococcal Activities against Multidrug-Resistant Strains. It is also used to prepare substituted isoindolines as inhibitors of dipeptidyl peptidase 8/9 (DPP8/9).