A mixture of 3-(5-bromopyrimidin-2-yl)aniline (intermediate 4, 220 mg; 0.88 mmol; 1.0 eq.), 1-(1-Boc-piperidino)pyrazole-4-boronic acid (389 mg; 1.3 mmol; 1.5 eq.), Pd(PPh3)4 (51 mg; 0.04 mmol; 0.05 eq.) and K2CO3 (365 mg; 2.6 mmol; 3.0 eq.) in dioxane/water (3.3: 1.65 mL) was heated at 12000 for 30 min in a sealed tube in MW. The reaction mixture was then diluted with EtOAc. The two phases were separated and aqueous phase was extracted with EtOAc. Combined organic phases were dried over magnesium sulfate, filtered and concentrated. Flash chromatography on silica (EtOAc:heptane, gradient from 50:50 to 100:0) afforded the title compound a beige solid (240 mg; 65%). 1H NMR (300 MHz, DMSO-d6) δ 9.09 (s, 2H), 8.52 (s, 1H), 8.11 (s, 1H), 7.67 (t, J=2.0 Hz, 1H), 7.57-7.53 (m, 1H), 7.14 (t, J=7.8 Hz, 1H), 6.69-6.66 (m, 1H), 5.25 (s, 2H), 4.46-4.36 (m, 1H), 4.08-4.04 (m, 2H), 2.94 (m, 2H), 2.08-2.04 (m, 2H), 1.87-1.75 (m, 2H), 1.43 (s, 9H). HPLC (Condition A): Rt 3.03 min (purity 99.0%). MS (ESI+): 421.4.
