N-[(6-Chloro-3′-formyl-3-biphenylyl)methyl]-N′-{[1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}-5-methyl-1,3-benzenedicarboxamide (30.36 mg, 0.044 mmol), 1-methylpiperazine (43.9 mg, 0.44 mmol, 10 eq) and acetic acid (2.51 μL, 0.044 mmol, 1 eq) were dissolved in DMSO (1.5 mL). The mixture was stirred in VX-2500 Multi-Tube Vortexer for overnight at room temperature. MP-triacetoxyborohydride (133 mg, 0.310 mmol, 7 eq) was then added and the mixture was stirred again in VX-2500 Multi-Tube Vortexer for overnight at room temperature. The reaction mixture was filtered through a polypropylene cartridge (10 mL tube) on Bohdan Miniblock in a reaction tube and concentrated in a Glas-Col evaporator. The reaction mixture was then purified using a Gilson HPLC with a water-acetonitrile with 0.1% TFA buffer. The desired product fractions were combined, filtered through amine cartouche (500 mg) on Bohdan Miniblock and concentrated in a Glas-Col evaporator, giving 18.38 mg (48.6%) of the title compound. LC-MS m/z 777 (M+H)+, 1.41 min (ret time).
