Trifluoroacetic acid → 7-(2-(2-((4-(Piperazin-1-yl)phenyl)amino)-5-(trifluoromethyl)pyrimidin-4-yl)ethyl)isoindolin-1-one

tert-Butyl 4-(4-((4-(2-(3-oxoisoindolin-4-yl)ethyl)-5-(trifluoromethyl)pyrimidin-2-yl)amino)phenyl)piperazine-1-carboxylate (I63) (0.080 g, 0.137 mmol) was dissolved in DCM (5 mL) under an atmosphere of nitrogen. Trifluoroacetic acid (0.210 mL, 2.75 mmol) was added to the solution and the reaction was stirred at room temperature for 1 hour and then at 35° C. for another 30 minutes. More trifluoroacetic acid (0.100 mL) was added and the reaction was further stirred at 35° C. for another 30 minutes. Volatiles were removed in vacuo then EtOAc (70 mL) and 2 M aq. NaOH (70 mL) were added to the residue and the layers were separated. The aqueous layer was extracted with EtOAc (2×70 mL), the combined organics were washed with water (50 mL), brine (50 mL), dried (MgSO4), filtered and concentrated in vacuo to give an oily solid which was taken up in DCM (˜10 mL) and concentrated in vacuo. The process was repeated twice after which the sample was further dried on high-vacuum to give the title compound (15) (0.050 g, 75% yield) as an off-white solid; 1H NMR (400 MHz, d6-DMSO) δ 9.94 (s, 1H), 8.56 (s, 1H), 8.48 (s, 1H), 7.59-7.52 (m, 2H), 7.47-7.36 (m, 2H), 7.23-7.11 (m, 1H), 6.87 (d, J=9.0 Hz, 2H), 4.31 (s, 2H), 3.56 (t, J=7.6 Hz, 2H), 3.11 (t, J=7.4 Hz, 2H), 3.01-2.95 (m, 4H), 2.86-2.79 (m, 4H). LCMS Method A: rt 4.40 min; m/z 483.8 [M+H]+.