Yield:1186609-65-3 87%

Reaction Conditions:

with palladium 10% on activated carbon;hydrogen in methanol;ethyl acetate; under 3102.97 Torr; for 7 h;

Steps:

(i) 3-Methoxy-1H-pyrazolo[3,4-b]pyridine-5-amine (8)

A solution of compound 7 (1.4 g, 7.2 mmol) in EtOAc/MeOH (1:1, 40 mL) was hydrogenation over 10% Pd/C (0.8 g) at 60 psi for 7 h. The catalyst was filtered off through a layer of Celite, and the filtrate was concentrated in vacuo. The crude product was purified by silica gel column chromatography (100:4 CH₂Cl₂/MeOH) to give 8 (1.03 g, 87%) as an off-white solid, mp 174-176 °C. ¹H NMR (DMSO-d₆): δ 11.9 (br s, 1H), 8.01 (d, J = 2.5 Hz, 1H), 7.07 (dd, J = 2.5, 0.5 Hz, 1H), 4.97 (s, 2H), 3.94 (s, 3H).

References:

Wang, Min;Gao, Mingzhang;Miller, Kathy D.;Zheng, Qi-Huang [Bioorganic and Medicinal Chemistry Letters,2013,vol. 23,# 4,p. 1017 - 1021]