Sulfuric Acid → 8-cyclopropylmethyl-6-(4-methoxy-phenyl)-2-phenylamino-5,8-dihydro-6H-pyrido[2,3-d]pyrimidine-7-one

Participants

Reaction Conditions

Reaction Steps

To a solution of crude 3-(2-phenylamino-4-cyclopropylmethylamino-pyrimidin-5-yl)-2-(4-methoxy-phenyl)-propionic acid methyl ester (51.3 mg) (from Example 14a supra) in glacial acetic acid (1 mL) was added concentrated sulfuric acid (0.1 mL) in one portion. The reaction mixture was heated at 85° C. for 3 hours. The reaction mixture was cooled, diluted with ethyl acetate (50 mL) and quenched with 2 N aqueous sodium hydroxide solution. The organic layer was separated and successively washed with water (10 mL) and brine (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by preparative thin layer chromatography to give 8-cyclopropylmethyl-6-(4-methoxy-phenyl)-2-phenylamino-5,8-dihydro-6H-pyrido[2,3-d]pyrimidine-7-one as a light yellow amorphous solid. (Yield 6.7 mg, 14.8%, 2 steps).

Provenance & Evidence