Pentane → 2-Cyclopentyl-1-(3,4-dichlorophenyl)ethanone

Temperature

-78 °C

A solution of pentane (50 mL), diethyl ether (50 mL) and iodomethylcyclopentane (prepared as in PCT WO2004/052869 A1 Example 1, 3.9 g, 18.6 mmol) was cooled to −78° C. and a solution of t-butyl lithium in pentane (1.7 M, 18.5 mL, 31.5 mmol) was added dropwise. The mixture was then stirred at −78° C. for 30 min and then warmed to room temperature and stirred for 30 min and finally recooled to −78° C. To this mixture was then added a solution of 3,4-dichlorobenzaldehyde (5.0 g, 28.6 mmol) in diethyl ether (20 mL) dropwise. The mixture was then stirred at −78° C. for 1 h and then warmed up to room temperature and stirred overnight. The mixture was then quenched by the addition of a saturated aqueous ammonium chloride solution (50 mL). The organic layer was then separated and washed with a saturated brine solution (50 mL), dried over magnesium sulfate, filtered and the filterate concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 10% ethyl acetate/hexanes) afforded 2-cyclopentyl-1-(3,4-dichloro-phenyl)-ethanone (2.36 g, 50%) as a yellow solid.

1. temperaturewarmed to room temperature
2. stirringstirred for 30 min
3. customfinally recooled to −78° C
4. stirringThe mixture was then stirred at −78° C. for 1 h
5. temperaturewarmed up to room temperature
6. stirringstirred overnight
7. customThe mixture was then quenched by the addition of a saturated aqueous ammonium chloride solution (50 mL)
8. customThe organic layer was then separated
9. washwashed with a saturated brine solution (50 mL)
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. concentrationthe filterate concentrated in vacuo

ORD record

ord-ee96d8970d6a404c95f3529cea5ab720

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08222416B2