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

HRID 1772089Notes

Reaction equation

HRID 1772089 reaction equation
[CH3:1][N:2]1[CH2:7][CH2:6][N:5]2[N:8]=[C:9]([N+:11]([O-])=O)[CH:10]=[C:4]2[CH2:3]1>C(O)C>[CH3:1][N:2]1[CH2:7][CH2:6][N:5]2[N:8]=[C:9]([NH2:11])[CH:10]=[C:4]2[CH2:3]1

Participants

3

Reactant 1

HCID 580440245-Methyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-A]pyrazine

Product 1

HCID 580439335-methyl-4H,5H,6H,7H-pyrazolo[1,5-a]pyrazin-2-amineYield 988.6%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

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 5-methyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine 103j (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 5-methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine 103k (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).

Workup

  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. additionCelite 521 (1.0 g) was 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

Sources & evidence

ORD record
ord-5f4f6ee4d3994edbada454f21127bfcd
Source dataset
uspto-grants-2016_02
Patent number
US09249123B2

Reaction notes

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