To a solution of N-[3-(2-chloro-pyrimidin-4-ylethenyl)-phenyl]-2,2,2-trifluoro-acetamide (See Example 1, step B) (5.0 g) in DMF (40 mL) were added 1-amino-3-fluoropyridinium nitrate (5.4 g) and K2CO3 (6.0 g). The reaction was kept stirring at RT for 1.5 h. The DMF solution was poured into 5% LiCl solution (60 mL) and extracted with EtOAc (2×30 mL). The combined organic phase were dried (Na2SO4) and concentrated. The crude products were separated through silica gel column chromatography to afford two products. The first to elute was N-{3-[3-(2-chloro-4-pyrimidinyl)-6-fluoropyrazolo[1,5-a]pyridin-2-yl]phenyl}-2,2,2-trifluoroacetamide (2.0 g, 30% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 7.08 (d, 1H, J=5.49 Hz), 7.45 (d, 1H, J=7.68 Hz), 7.55 (t, 1H, J=7.96 Hz), 7.73-7.79 (m, 1H), 7.83 (d, 1H, J=0.91 Hz), 7.95 (t, 1H, J=1.74 Hz), 8.41 (dd, 1H, J=9.97, 5.76 Hz), 8.49 (d, 1H, J=5.49 Hz), 9.27 (dd, 1H, J=4.30, 2.29 Hz). ES-LC/MS m/z=436 [M+H]+.
