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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence