General procedure: A solution of 1-(2-methoxyethyl)-4-nitro-1H-pyrazole (2.5 g, 14.60 mmol) in ethanol (250 mL) was added to a standard flask, followed by palladium carbon (20% w/w, 0.50 g). The flask was evacuated and replaced with hydrogen. The reaction was stirred under hydrogen atmosphere (1 atm) for 16 hours. After completion of the reaction, the reaction solution was filtered through a sintered funnel with a diatomaceous earth pad and the filter cake was washed with methanol. The filtrate was concentrated under reduced pressure to afford 1-(2-methoxyethyl)-1H-pyrazol-4-amine (2.0 g, 97% yield), which was used directly in the next reaction without further purification.1H NMR (400 MHz, CDCl3): δ 7.03 (s, 1H), 6.89 (s, 1H), 4.19-4.17 (t, 2H), 3.78 ( br s, 2H), 3.67-3.64 (t, 2H), 3.21 (s, 3H). Mass spectrum (MS): 142.11 (M + H).
