5-Ethyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine → 5-Ethyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine

Participants

Reaction Steps

A 500-mL Parr hydrogenation bottle was charged with 285a (1.8 g, 9 mmol), 10% palladium on carbon (50% wet, 500 mg dry weight) and ethanol (100 mL). The bottle was evacuated, charged with hydrogen gas to a pressure of 50 psi and shaken for 1 h on a Parr hydrogenation apparatus. The catalyst was removed by filtration through a pad of Celite 521 washing with 1:1 methylene chloride:methanol (500 mL). The resulting solution was concentrated under reduced pressure to afford a 71% yield (1.7 g) of crude 285b.

Provenance & Evidence