Dimethylformamide → ethyl (+/-)-4-formyl-alpha-phenyl-1H-pyrazole-l-acetate

HRID 1756948Notes

Reaction equation

HRID 1756948 reaction equation
P(Cl)(Cl)(Cl)=O.[C:6]1([CH:12]([N:18]2[CH:22]=[CH:21][CH:20]=[N:19]2)[C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.CN([CH:26]=[O:27])C>>[CH:26]([C:21]1[CH:20]=[N:19][N:18]([CH:12]([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=2)[C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH:22]=1)=[O:27]

Participants

4

Reactant 3

HCID 6228Dimethylformamide2×HCID 24813Phosphorus oxychlorideHCID 4257156ethyl 2-phenyl-2-(1H-pyrazol-1-yl)acetate

Product 1

HCID 10563150ethyl (+/-)-4-formyl-alpha-phenyl-1H-pyrazole-l-acetateYield 89%

Conditions

Temperature
70 °C

Procedure

Phosphorous oxychloride (7.0 mL, 75 mmol) was added dropwise to 14 mL DMF at 0° C. under an atmosphere of N2. The resulting solution was stirred for 0.5 hour and then a solution of ethyl (±)-α-phenyl-1H-pyrazole-1-acetate (5.76 g, 25 mmol) in 5 mL DMF was added dropwise. The resulting orange solution was warmed to 70° C. for 16 hours. The reaction mixture was cooled to 0° C. and carefully quenched with saturated Na2CO3 solution. The reaction mixture was partitioned between water and ether and the ether layer was dried over MgSO4, filtered, and concentrated to give an orange oil. Chromatography (15% EtOAc/hexanes on silica) gave 5.73 g (89%) of the title compound as a yellow/green oil which solidified upon standing; mp 68°-70° C.

Workup

  1. temperatureThe reaction mixture was cooled to 0° C.
  2. customcarefully quenched with saturated Na2CO3 solution
  3. customThe reaction mixture was partitioned between water and ether
  4. dry with materialthe ether layer was dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give an orange oil

Sources & evidence

ORD record
ord-7f9ba16a1aa146df8fffca99d24b9428
Source dataset
uspto-grants-1995_08
Patent number
US05441975

Reaction notes

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