6-Chloro-N-[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-1-(1-methylethyl)-1H-pyrazolo[3,4-b]pyridine-4-carboxamide (0.15 g, 0.401 mmol), 4-pyridinol (0.057 g, 0.602 mmol), cesium carbonate (0.261 g, 0.802 mmol), and 1-(2-pyridinyl)-2-propanone (10.85 mg, 0.080 mmol) were sequentially dissolved in DMSO (4.0 mL). Next added copper(I) bromide (5.76 mg, 0.040 mmol) and the suspension was stirred under nitrogen (degassed) for 1 min. The sealed reaction mixture was stirred with heating at 110° C. (heating block) for 20 h, and then allowed to cool to room temperature overnight. The reaction mixture was diluted with EtOAc (25 mL) and water. The contents were vigorously stirred and then filtered through Celite, washing the filter pad with 20% THF/EtOAc. The layers were separated and the aq. layer extracted with EtOAc. The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo to a dark residue that was dried under hi-vacuum overnight. The crude product was purified by silica gel chromatography (eluent: gradient of 5-95% Dichloromethane/Chloroform containing 2M Ammonia (in methanol). The collected product was washed with MTBE, filtered, and dried in a vacuum oven at 45° C. for 5 hr. The final product was collected as 0.075 g (42%). LCMS E-S (M+H)=433.2. 1H NMR (400 MHz, DMSO-d6) δ ppm 1H NMR (400 MHz, DMSO-d6) δ ppm 1.52 (d, J=6.57 Hz, 6H), 2.13 (s, 3H), 2.22 (s, 3H), 4.41 (d, J=5.05 Hz, 2H), 5.18-5.30 (m, 1H), 5.91 (s, 1H), 6.30-6.40 (m, 2H), 7.91 (s, 1H), 8.41 (s, 1H), 8.57-8.65 (m, 2H), 8.92 (t, J=4.93 Hz, 1H), 11.58 (s, 1H).
