5-Methyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-A]pyrazine → 5-methyl-4H,5H,6H,7H-pyrazolo[1,5-a]pyrazin-2-amine

A 500-mL Parr reactor bottle was purged with nitrogen and charged with 10% palladium on carbon (50% wet, 800 mg dry weight) and a solution of 113d (4.00 g, 2.20 mmol) in ethanol (160 mL). The bottle was attached to Parr hydrogenator, evacuated, charged with hydrogen gas to a pressure of 45 psi and shaken for 2 h. After this time, the hydrogen was evacuated, and nitrogen was charged into the bottle. CELITE® 521 (1.0 g) was added, and the mixture was filtered through a pad of CELITE® 521. The filter cake was washed with ethanol (2×75 mL), and the combined filtrates were concentrated to dryness under reduced pressure to afford a 99% yield of 113e (3.31 g) as an orange solid: 1H NMR (300 MHz, CDCl3) δ 5.34 (s, 1H), 3.98 (t, 2H, J=5.4 Hz), 3.52 (s, 3H), 2.84 (t, 2H, J=5.7 Hz), 2.45 (s, 3H); MS (ESI+) m/z 153.1 (M+H)

1. customA 500-mL Parr reactor bottle was purged with nitrogen
2. additioncharged with 10% palladium on carbon (50% wet, 800 mg dry weight)
3. customevacuated
4. additioncharged with hydrogen gas to a pressure of 45 psi
5. customAfter this time, the hydrogen was evacuated
6. additionnitrogen was charged into the bottle
7. additionwas added
8. filtrationthe mixture was filtered through a pad of CELITE® 521
9. washThe filter cake was washed with ethanol (2×75 mL)
10. concentrationthe combined filtrates were concentrated to dryness under reduced pressure

ORD record

ord-4d2d032289364cb588db0843564c8d40

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08921353B2