A mixture of N4-(5-cyclopropyl-1H-pyrazol-3-yl)-N2-((6-fluoro-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrrolo[3,2-b]pyridin-5-yl)methyl)-N2-methylpyrimidine-2,4-diamine (40 mg, 0.1 mmol) and tetrabutyl ammonium fluoride (260 mg, 1 mmol) in THF (5 mL) was heated at 63° C. for 18 h. The reaction mixture was poured into water (10 mL) and the pH was adjusted to 10 by addition of an NH4OH solution. The mixture was extracted with EtOAc (50 mL×3) and the combined extracts dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by reverse phase preparative HPLC to afford 8 mg, (20%) of N4-(5-cyclopropyl-1H-pyrazol-3-yl)-N2-((6-fluoro-1H-pyrrolo[3,2-b]pyridin-5-yl)methyl)-N2-methylpyrimidine-2,4-diamine as a white solid. 1H NMR (500 MHz, DMSO) δ 11.8 (brs, 1H), 11.3 (brs, 1H), 9.33 (brs, 1H), 7.85 (d, J=5 Hz, 1H), 7.65 (d, 0.1=10 Hz, 1H), 7.58 (d, J=3 Hz, 1H), 6.51 (s, 1H), 6.00-6.20 (brs, 2H), 5.06 (s, 2H), 3.16 (s, 3H), 1.81 (s, 1H), 0.85 (s, 2H), 0.59 (s, 2H); MS (ESI): m/z=379.3 [M+1]+.
