Phosphorus oxychloride → 3-chloro-1-(3-fluorobenzoyl)-4,5-dihydro-1H-pyrazole

HRID 1629973Notes

Reaction equation

HRID 1629973 reaction equation
P(Cl)(Cl)([Cl:3])=O.[F:6][C:7]1[CH:8]=[C:9]([CH:18]=[CH:19][CH:20]=1)[C:10]([N:12]1[CH2:16][CH2:15][C:14](=O)[NH:13]1)=[O:11]>>[Cl:3][C:14]1[CH2:15][CH2:16][N:12]([C:10](=[O:11])[C:9]2[CH:18]=[CH:19][CH:20]=[C:7]([F:6])[CH:8]=2)[N:13]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 711848671-(3-Fluorobenzoyl)pyrazolidin-3-one

Product 1

HCID 711849653-chloro-1-(3-fluorobenzoyl)-4,5-dihydro-1H-pyrazoleYield 88.9%

Conditions

Temperature
85 °C

Procedure

Phosphorus oxychloride (54 ml for 5.4 gm of SM, 10 volume) was added drop wise directly to 1-(3-fluorobenzoyl)pyrazolidin-3-one (5.4 gm, 0.0238 mmol, 1 equiv.) at 0° C. and then refluxed at 85° C. for an hour. The reaction mixture was cooled to RT, concentrated and basified with solid NaCO3 (pH: 8-9), extracted with dichloromethane (100 ml×2) and concentrated. The crude product was purified by silica gel column using (60-120) mesh to get the pure product as off green solid (4.8, 88.9% yield).

Workup

  1. temperatureThe reaction mixture was cooled to RT
  2. concentrationconcentrated and basified with solid NaCO3 (pH: 8-9)
  3. extractionextracted with dichloromethane (100 ml×2)
  4. concentrationconcentrated
  5. customThe crude product was purified by silica gel column
  6. customto get the pure product as off green solid (4.8, 88.9% yield)

Sources & evidence

ORD record
ord-0af00d41fd6347378be8242f006516be
Source dataset
uspto-grants-2014_07
Patent number
US08791114B2

Reaction notes

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