Methylamine → 5-Methyl-2-nitro-4,5-dihydropyrazolo[1,5-a]pyrazin-6(7H)-one

HRID 407764Notes

Reaction equation

HRID 407764 reaction equation
Cl[CH2:2][C:3]1[N:7]([CH2:8][C:9]([O:11]CC)=O)[N:6]=[C:5]([N+:14]([O-:16])=[O:15])[CH:4]=1.[CH3:17][NH2:18]>ClCCl.O>[CH3:17][N:18]1[C:9](=[O:11])[CH2:8][N:7]2[N:6]=[C:5]([N+:14]([O-:16])=[O:15])[CH:4]=[C:3]2[CH2:2]1

Participants

5

Reactant 2

HCID 6329MethylamineHCID 86684030Ethyl 2-(5-(Chloromethyl)-3-nitro-1H-pyrazol-1-yl)acetate

Product 1

HCID 866840315-Methyl-2-nitro-4,5-dihydropyrazolo[1,5-a]pyrazin-6(7H)-oneYield 57.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of 146b (1.0 g, 4.0 mmol) in dichloromethane (30 mL) was added a solution of CH3NH2 (1.07 g, 12.0 mmol, 35% in methanol). This reaction mixture was stirred at room temperature for 3 h and diluted with water (30 mL). The organic layer was separated, dried over Na2SO4, and concentrated under reduced pressure. The residual was purified by silica-gel column chromatography eluting with 30:1 dichloromethane/methanol to afford 146c (450 mg, 57%) as a yellow solid. MS-ESI: [M+H]+ 196.9

Workup

  1. customThe organic layer was separated
  2. dry with materialdried over Na2SO4
  3. concentrationconcentrated under reduced pressure
  4. customThe residual was purified by silica-gel column chromatography
  5. washeluting with 30:1 dichloromethane/methanol

Sources & evidence

ORD record
ord-546935d165a24ea189d598e4fead747b
Source dataset
uspto-grants-2014_06
Patent number
US08754077B2

Reaction notes

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