Citric Acid → Ethyl 3-(4-pyridyl)-3-oxopropionate

To a solution of 4-pyridinecarboxylic acid (50.0 g, 406 mmol) in tetrahydrofuran (250 ml) was added 1,1′-carbonylbis-1H-imidazole (72.5 g, 447 mmol), and the mixture was stirred at room temperature for 30 min. To the reaction solution was added monoethyl malonate magnesium salt (82.9 g, 487 mmol), and the mixture was heated under reflux for 30 min. To the reaction solution were added ethyl acetate (200 ml) and water (200 ml), and citric acid was added until the pH of the aqueous layer became 7. The reaction solution was extracted with ethyl acetate (400 ml×2). The extract was washed with saturated brine, dried over anhydrous magnesium sulfate and evaporated under reduced pressure. The residue was washed with diisopropyl ether-hexane and recrystallized from diisopropyl ether-hexane to give ethyl 3-oxo-3-(4-pyridyl)propionate (13.3 g, 17%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 30 min
3. additionwas added until the pH of the aqueous layer
4. extractionThe reaction solution was extracted with ethyl acetate (400 ml×2)
5. washThe extract was washed with saturated brine
6. dry with materialdried over anhydrous magnesium sulfate
7. customevaporated under reduced pressure
8. washThe residue was washed with diisopropyl ether-hexane
9. customrecrystallized from diisopropyl ether-hexane

ORD record

ord-a830c89a4bbf40ac82f19b6212a7c902

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06982348B2