To a solution of 1-[7-chloro-2-(4-pyridinyl)pyrazolo[1,5-a]pyridin-3-yl]ethanone (0.68 g, 2.5 mmol) in toluene (10 mL) was added successively rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (100 mg, 0.15 mmol), cesium carbonate (1.2 g, 3.8 mmol), cyclopentylamine (1.5 mL, 12.5 mmol), and palladium (II) acetate (25 mg, 0.1 mmol). The resulting mixture was stirred at 90° C. for 24 hours, at which time the reaction was judged complete by thin layer chromatography. The solution was cooled to room temperature and ethyl acetate and water were added to the reaction mixture. The phases were separated, and the aquous phase again extracted with ethyl acetate. The combined organic phases were dried (magnesium sulfate), filtered and concentrated. The resulting residue was purified by flash chromatography (1:1 hexanes-ethyl acetate) to give 1-[7-(cyclopentylamino)-2-(4-pyridinyl)pyrazolo[1,5-a]pyridin-3-yl]ethanone (0.64 g, 80%) as a yellow foam. 1H NMR (CDCl3): δ 8.80 (d, 2H), 7.65 (d, 1H), 7.60 (d, 2H), 7.50 (t, 1H), 6.20 (d, 1H), 6.06 (d, 1H), 4.0 (m, 1H), 2.26 (s, 3H), 1.6–2.2 (m, 8H); MS m/z 321 (M+1).
