反应详情

温度

-78 °C

A solution of diisopropylamine (2.4 mL, 16.80 mmol) in dry tetrahydrofuran (7.5 mL) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (2.5 mL) was cooled to −78° C. under nitrogen and then treated with a 2.5M solution of n-butyllithium in hexanes (6.7 mL, 16.80 mmol). The resulting reaction mixture was stirred at −78° C. for 30 min and then treated dropwise with a solution of 4-(trifluoromethylthio)phenylacetic acid (1.89 g, 8.00 mmol) in dry tetrahydrofuran (7.5 mL) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (2.5 mL). The reaction mixture was allowed to stir at −78° C. for 55 min, at which time, a solution of iodomethylcyclopentane (1.85 g, 8.80 mmol) in a small amount of dry tetrahydrofuran was added dropwise. The reaction mixture was allowed to warm to 25° C. where it was stirred for 41 h. The reaction mixture was quenched with water and then concentrated in vacuo to remove tetrahydrofuran. The remaining aqueous phase was acidified to pH=2 with a 10% aqueous hydrochloric acid solution and then extracted with ethyl acetate (1×300 mL). The organic layer was washed with a saturated aqueous sodium chloride solution (1×100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 70-230 mesh, 3/1 hexanes/ethyl acetate) afforded 3-cyclopentyl-2-(4-trifluoromethylsulfanyl-phenyl)propionic acid (1.47 g, 58%) as a cream solid: mp 69-71° C.; EI-HRMS m/e calcd for C15H17F3O2S (M+) 318.0901, found 318.0912.

1. customThe resulting reaction mixture
2. stirringto stir at −78° C. for 55 min, at which time
3. temperatureto warm to 25° C. where it
4. stirringwas stirred for 41 h
5. customThe reaction mixture was quenched with water
6. concentrationconcentrated in vacuo
7. customto remove tetrahydrofuran
8. extractionextracted with ethyl acetate (1×300 mL)
9. washThe organic layer was washed with a saturated aqueous sodium chloride solution (1×100 mL)
10. dry with materialdried over sodium sulfate
11. filtrationfiltered
12. concentrationconcentrated in vacuo