3-Chlorophenylacetic acid → 2-(3-Chloro-phenyl)-3-cyclopentyl-propionic acid

Temperature

-78 °C

A solution of freshly prepared lithium diisopropylamide (141.3 mL of a 0.32M stock solution, 45.0 mmol) cooled to −78° C. was treated with (3-chloro-phenyl)-acetic acid (3.41 g, 20.0 mmol) in tetrahydrofuran/1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (49.7 mL, 3:1). The resulting reaction solution was stirred at −78° C. for 1 h. Iodomethylcyclopentane (4.64 g, 22.08 mmol) was then added in 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (4.64 mL). The reaction mixture was stirred at −78° C. for 4 h. The reaction was then warmed to 25° C. and was stirred at 25° C. for 48 h. The solution was then quenched by the slow addition of the reaction mixture to a 2N aqueous hydrochloric acid solution (50 mL). The product was extracted into ethyl acetate (1×150 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 85/15 hexanes/ethyl acetate) afforded 2-(3-chloro-phenyl)-3-cyclopentyl-propionic acid (3.68 g, 72.9%) as a yellow solid: mp 70-72° C.; EI-HRMS m/e calcd for C14H17ClO2 (M+) 252.0917, found 252.0915.

1. customThe resulting reaction solution
2. stirringThe reaction mixture was stirred at −78° C. for 4 h
3. temperatureThe reaction was then warmed to 25° C.
4. stirringwas stirred at 25° C. for 48 h
5. customThe solution was then quenched by the slow addition of the reaction mixture to a 2N aqueous hydrochloric acid solution (50 mL)
6. extractionThe product was extracted into ethyl acetate (1×150 mL)
7. dry with materialThe organic layer was dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo

ORD record

ord-760b50b36ae749d5b2c764f10be15f1e

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06610846B1