4-Fluoroaniline → 2-Ethyl-3-(4-fluorophenyl)pyrido[2,3-d]pyrimidin-4(3H)-one

Participants

Reaction Conditions

Reaction Steps

A suspension of the pyrido-oxazine (16) (0.5 g, 2.84 mmol) and 4-fluoroaniline (0.32 g, 2.84 mmol) in toluene (21 mL) was heated to reflux overnight. The solution was concentrated to dryness under reduced pressure and ethylene glycol (2 mL) and sodium hydroxide (5 mg) were added. The mixture was heated again to 120° C. for 4 h, and the ethylene glycol was distilled off under reduced pressure. The resulting dark brown solid was subjected to silica-gel column chromatography [eluent: Ethyl acetate:Hexane, 20:80, ν/ν->100:0, ν/ν] to give the title pyrido-pyrimidinone (17) (244 mg, 32%) as a beige solid:

Provenance & Evidence