Methyl iodide → Methyl 3-benzyloxy-5-methyl-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate

HRID 1453855Notes

Reaction equation

HRID 1453855 reaction equation
[CH2:1]([O:8][C:9]1[C:10]([C:19]([O:21][CH3:22])=[O:20])=[N:11][N:12]2[CH2:17][CH2:16][NH:15][C:14](=[O:18])[C:13]=12)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.I[CH3:24].[H-].[Na+]>CN(C=O)C>[CH2:1]([O:8][C:9]1[C:10]([C:19]([O:21][CH3:22])=[O:20])=[N:11][N:12]2[CH2:17][CH2:16][N:15]([CH3:24])[C:14](=[O:18])[C:13]=12)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 57528498HCID 57528498, compound

Product 1

HCID 68951321Methyl 3-benzyloxy-5-methyl-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of methyl 3-benzyloxy-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate (300 mg, 0.966 mmol) in DMF (5 mL) was added iodomethane (74 μL, 1.20 mmol). The solution was cooled to 0° C., treated with NaH (36 mg, 1.49 mmol, 95% dispersion in oil), and stirred for 10 minutes. The reaction was removed from the ice bath and allowed to gradually warm to room temperature. The mixture was partitioned between EtOAc and brine, and the organic extract was dried over Na2SO4 and concentrated in vacuo. Purification by reverse phase chromatography on a C-18 column using a gradient elution of 95-5% H2O (0.1% TFA)/CH3CN (0.1% TFA) and collection and concentration of the appropriate fractions afforded the title product. 1H NMR (400 MHz, CDCl3) δ 7.54-7.53 (m, 2H), 7.37-7.28 (m, 3H), 5.36 (s, 2H), 4.38-4.41 (t, 2H), 3.92 (s, 3H), 3.76-3.72 (t, 2H), 3.16 (s, 3H); ES MS (M+1)=316.

Workup

  1. customThe reaction was removed from the ice bath
  2. temperatureto gradually warm to room temperature
  3. customThe mixture was partitioned between EtOAc and brine
  4. extractionthe organic extract
  5. dry with materialwas dried over Na2SO4
  6. concentrationconcentrated in vacuo
  7. customPurification by reverse phase chromatography on a C-18 column
  8. washa gradient elution of 95-5% H2O (0.1% TFA)/CH3CN (0.1% TFA) and collection and concentration of the appropriate fractions

Sources & evidence

ORD record
ord-e2f40dfc29274cafb238870e7a61ca3b
Source dataset
uspto-grants-2009_01
Patent number
US07476666B2

Reaction notes

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