Sulfuric Acid → 8-phenyl-2-phenylamino-6-pyridin-3-yl-5,8-dihydro-6H-pyrido[2,3-d]pyrimidin-7-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(2,4-diphenylamino-pyrimidin-5-yl)-2-pyridin-3-yl-propionic acid ethyl ester (60 mg, 0.36 mmol) (from Example 10b supra) was added 5% concentrated sulfuric acid in glacial acetic acid (3 mL) in one portion. The reaction mixture was heated at 120° C. for 3 hours. The reaction mixture was then diluted with ethyl acetate (100 mL) and quenched with 2 N aqueous sodium hydroxide solution. The organic layer was separated and successively washed with water (30 mL) and brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give the crude product which was crystallized from ethyl acetate-hexanes to give 8-phenyl-2-phenylamino-6-pyridin-3-yl-5,8-dihydro-6H-pyrido[2,3-d]pyrimidin-7-one as a white solid. (Yield 37.3 mg, 69.3%).

Provenance & Evidence