Hydrochloric Acid → methyl 3-benzyloxy-1-methyl-1H-pyrazol-4-ylacetate

HRID 1295223Notes

Reaction equation

HRID 1295223 reaction equation
[CH2:1]([O:8][C:9]1[C:13]([CH2:14][C:15]#N)=[CH:12][N:11]([CH3:17])[N:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-:18].[Na+].[O:20]1[CH2:24]CCC1.Cl>C(O)C>[CH2:1]([O:8][C:9]1[C:13]([CH2:14][C:15]([O:20][CH3:24])=[O:18])=[CH:12][N:11]([CH3:17])[N:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Procedure

A mixture of 3-benzyloxy-1-methyl-1H-pyrazol-4-ylacetonitrile (12.0 g), 4N aqueous sodium hydroxide solution (100 ml), tetrahydrofuran (100 ml) and ethanol (100 ml) was refluxed for 21 hrs. After cooling, the mixture was neutralized with dilute hydrochloric acid and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. A mixture of the residue, methyl iodide (4.95 ml), potassium carbonate (14.7 g) and N,N-dimethylformamide (100 ml) was stirred overnight at room temperature. The reaction solution was poured into water, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and methyl 3-benzyloxy-1-methyl-1H-pyrazol-4-ylacetate (12.2 g, yield 88%) was obtained as a yellow oil from a fraction eluted with ethyl acetate-hexane (1:1, volume ratio).

Workup

  1. temperaturewas refluxed for 21 hrs
  2. temperatureAfter cooling
  3. extractionextracted with ethyl acetate
  4. washThe ethyl acetate layer was washed with saturated brine
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated
  7. additionA mixture of the residue, methyl iodide (4.95 ml), potassium carbonate (14.7 g) and N,N-dimethylformamide (100 ml)
  8. additionThe reaction solution was poured into water
  9. extractionthe mixture was extracted with ethyl acetate
  10. washThe ethyl acetate layer was washed with saturated brine
  11. dry with materialdried (MgSO4)
  12. concentrationconcentrated

Sources & evidence

ORD record
ord-82a638a79ca3488184562bb221157e9f
Source dataset
uspto-grants-2007_07
Patent number
US07241785B2

Reaction notes

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