Sodium ethylate solution (21% T, 0.5 mL, 1.43 mmol) was added to ethanol followed by cyclopentylguanidine hydrochloride (323 mg, 1.98 mmol). The mixture was stirred at room temperature for 30 minutes. 1-[7-Chloro-2-(3-methyl-2-furyl)pyrazolo[1,5-a]pyridin-3-yl]-2-propyn-1-one (313 mg, 1.10 mmol) was added to the resultant solution and stirred at room temperature for 15 hours. The reaction mixture was concentrated. Ethyl acetate and water were added to the residue. The phases were separated, the organic phase dried (magnesium sulfate), filtered and concentrated. The residue was recrystallized from ethyl acetate. 4-[7-Chloro-2-(3-methyl-2-furyl)pyrazolo[1,5-a]pyridin-3-yl]-N-cyclopentyl-2-pyrimidinamine (280 mg, 65%) was obtained as a yellow solid. 1H-NMR (CDCl3): δ 8.50 (d, 1H), 8.15 (d, 1H), 7.49 (d, 1H), 7.27 (t, 1H), 7.06 (d, 1H), 6.41 (d, 1H), 6.36 (d, 1H), 5.10 (d, 1H), 4.35 (m, 1H), 2.12 (s, 3H), 2.08 (m, 2H), 1.78–1.53 (m, 6H). MS m/z 394 (M+1).
