Diisopropylamine → Ethyl 2-oxo-3-phenylcyclopentanecarboxylate

Temperature

-78 °C

To a solution of diisopropylamine (6.62 mL, 46.8 mmol) in THF (200 mL) at −78° C. was added a 1.6 M solution of n-butyllithium in hexanes (29.3 mL, 46.8 mmol). The solution was stirred for 30 min at −78° C. and treated with a solution of 2-phenylcyclopentanone (5 g, 31.2 mmol) in 50 mL of dry THF. After stirring for 30 min at −78° C., ethyl carbonocyanidate (3.36 mL, 34.3 mmol) was added to the reaction mixture. The resulting solution was warmed to 25° C. with stirring over 3 h. The reaction mixture was quenched with 10 mL of water, washed with brine, dried over anhydrous sodium sulfate, concentrated in vacuum, and purified by column chromatography on silica gel to afford ethyl 2-oxo-3-phenylcyclopentanecarboxylate (5.3 g, 22.82 mmol, 73% yield) as colorless oil. LC-MS (M+K)+=273.2. 1H NMR (500 MHz, CDCl3) δ ppm 7.32-7.39 (2H, m), 7.25-7.31 (1H, m), 7.19-7.25 (2H, m), 4.18-4.32 (2H, m), 3.29-3.55 (2H, m), 1.87-2.62 (4H, m), 1.28-1.39 (3H, m).

1. stirringAfter stirring for 30 min at −78° C.
2. temperatureThe resulting solution was warmed to 25° C.
3. stirringwith stirring over 3 h
4. customThe reaction mixture was quenched with 10 mL of water
5. washwashed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated in vacuum
8. custompurified by column chromatography on silica gel

ORD record

ord-d3d75de8a5a644a58a2ad9729b9b25c6

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08637525B2