Ammonium Chloride → 5-Cyclopropyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine

HRID 1918866Notes

Reaction equation

HRID 1918866 reaction equation
[CH:1]1([N:4]2[CH2:9][CH2:8][N:7]3[N:10]=[C:11]([N+:13]([O-])=O)[CH:12]=[C:6]3[CH2:5]2)[CH2:3][CH2:2]1.[NH4+].[Cl-]>C(O)C.O.[Fe]>[CH:1]1([N:4]2[CH2:9][CH2:8][N:7]3[N:10]=[C:11]([NH2:13])[CH:12]=[C:6]3[CH2:5]2)[CH2:3][CH2:2]1

Participants

6

Reactant 2

HCID 25517Ammonium ChlorideHCID 580442225-Cyclopropyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine

Product 1

HCID 580439305-Cyclopropyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amineYield 78.3%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A mixture of 5-cyclopropyl-2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine 135a (2.68 g, 12.9 mmol), Fe (3.6 g, 64.4 mmol) and NH4Cl (4.1 g, 77.4 mmol) in ethanol (30 mL) and water (5 mL) was heated at reflux for 2 h. After the completion of the reaction, the mixture was filtered off. And the solid was washed with ethanol (150 mL). The filtrate was evaporated in vacuo and the residue was extracted with methanol/methylene chloride (1/7). The combined extracts were dried over Na2SO4 and evaporated. The residue was purified on reverse phase Combi-flash to give 135b (1.8 g, 75%). MS: [M+H]+ 179.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 2 h
  3. customAfter the completion of the reaction
  4. filtrationthe mixture was filtered off
  5. washAnd the solid was washed with ethanol (150 mL)
  6. customThe filtrate was evaporated in vacuo
  7. extractionthe residue was extracted with methanol/methylene chloride (1/7)
  8. dry with materialThe combined extracts were dried over Na2SO4
  9. customevaporated
  10. customThe residue was purified on reverse phase Combi-flash

Sources & evidence

ORD record
ord-7f10e1497da7498db61efd3f2820c5e2
Source dataset
uspto-grants-2013_12
Patent number
US08618107B2

Reaction notes

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