A mixture of 4-({[1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}amino)-4-oxobutanoic acid (0.080 g, 0.198 mmol), (({3′-[(1-methyl-4-piperidinyl)methyl]-3-biphenylyl}methyl)amine, triethylamine (0.080 mL, 0.575 mmol) and dichloromethane (DCM) (3 mL) was stirred at room temperature overnight. The LC-MS suggested that the reaction was complete. The reaction was diluted with EtOAc and washed in turn with sat. aq. NaHCO3, then saturated aqueous NaCl. The organic phase was dried (Na2SO4) and evaporated to give a residue (175 mg). This residue was purified on a Gilson HPLC on RP column CH3CN—H2O (0.1% TFA) gradient [10-80%]. Fractions containing the desired product were combined and evaporated to a small volume, then treated with saturated aqueous NaHCO3. The mixture was extracted with EtOAc (2×) and the combined extracts were washed with saturated aqueous NaCl and dried (Na2SO4), then evaporated to a glassy solid (52.2 mg). LC-MS m/z 680.7 (M+H)+, 0.76 min (ret time).
