1-Cyclopropyl-4-nitro-1H-pyrazole → 1-Cyclopropyl-1H-pyrazol-4-amine

Participants

Reaction Steps

A 250-mL Parr reactor bottle was purged with nitrogen and charged with 10% palladium on carbon (50% wet, 117 mg dry weight) and a solution of 109a (500 mg, 6.73 mmol) in ethanol (36 mL). The bottle was attached to a Parr hydrogenator, evacuated, charged with hydrogen gas to a pressure of 50 psi and shaken for 2 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 94% yield of 109b (378 mg) as a purple oil: 1H NMR (300 MHz, CDCl3) δ 7.13 (s, 1H), 7.07 (s, 1H), 3.47 (m, 1H), 2.87 (br s, 2H), 0.96 (m, 4H); MS (ESI+) m/z 124.1 (M+H).

Provenance & Evidence