tert-Butyl 3-(3-(1-cyanocyclopropyl)-5-(3-(trifluoromethyl)-1-trityl-1H-pyrazolo[3,4-b]pyridin-4-yl)phenyl)propylcarbamate (72 mg, 0.09893 mmol) was dissolved in DCM (3 mL) and cooled to 0° C. Triethylsilane (46.01 mg, 63.20 μL, 0.3957 mmol) was added followed by TFA (0.5 mL). The reaction was stirred at 0° C. for 1 hour then the solvent removed under reduced pressure. The crude product was dissolved in DMSO and purified by FractionLynx. The fractions were passed through bicarbonate cartridges to obtain free base and lyophilised to give 1-(3-(3-aminopropyl)-5-(3-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-4-yl)phenyl)cyclopropanecarbonitrile as a white solid (22 mg, 57%).
