1-Cyclopropyl-3-nitro-1H-pyrazole → 1-Cyclopropyl-1H-pyrazol-3-amine

Participants

Reaction Steps

A 250-mL Parr reactor bottle was purged with nitrogen and charged with 10% palladium on carbon (50% wet, 137 mg dry weight) and a solution of 123a (600 mg, 3.92 mmol) in ethanol (70 mL). The bottle was attached to a Parr hydrogenator, evacuated, charged with hydrogen gas to a pressure of 50 psi and shaken for 3 h. After this time, the hydrogen was evacuated, and nitrogen was charged into the bottle. Celite 521 (1.00 g) was added, and the mixture was filtered through a pad of Celite 521. The filter cake was washed with ethanol (2×25 mL), and the combined filtrates were concentrated to dryness under reduced pressure to afford a 93% yield of 123b (450 mg) as a purple oil: 1H NMR (300 MHz, CDCl3) d 7.17 (d, 1H, J=2.4 Hz), 5.55 (d, 1H, J=2.4 Hz), 3.43 (m, 1H), 2.92 (br s, 2H), 1.01 (m, 2H), 0.93 (m, 2H); MS (ESI+) m/z 124.1 (M+H).

Provenance & Evidence