To a solution of 4-fluoro-1-(4-methoxy-3-(pyrazin-2-yl)phenyl)-1-(2-(trifluoromethyl) pyridin-4-yl)-1H-isoindol-3-amine (0.65 g, 1.36 mmol) in DCM (12.5 ml), boron tribromide (0.718 ml, 4.20 mmol) was added dropwise at 0° C. The mixture was stirred at 0° C. for 1 hour and then allowed to reach room temperature. Water (5 ml) was added and the pH was adjusted to approx 8 with aqeuous conc. NH3. The organic phase was separated and aqueous phase was extracted with DCM (20 mL). The combined organic phases were passed through a phase separator (Sorbent) and concentrated under reduced pressure. The residue was purified twice by preparative chromatography to give the title compound (210 mg, 32%).
