Methanol → 2-(4-Bromo-phenyl)-3-cyclopentyl-propionic acid methyl ester

Temperature

25 °C

A solution of 2-(4-bromo-phenyl)-3-cyclopentyl-propionic acid (1.37 g, 4.61 mmol) in methanol (23 mL) was treated slowly with 5 drops of concentrated sulfuric acid. The resulting reaction mixture was heated under reflux for 42 h. The reaction mixture was allowed to cool to 25° C. and then concentrated in vacuo to remove methanol. The residue was diluted with ethyl acetate (200 mL). The organic phase was washed with a saturated aqueous sodium bicarbonate solution (1×100 mL), 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, 19/1 hexanes/ethyl acetate) afforded 2-(4-bromo-phenyl)-3-cyclopentyl-propionic acid methyl ester (1.40 g, 97%) as a light yellow oil: EI-HRMS m/e calcd for C15H19BrO2 (M+) 310.0568, found 310.0569.

1. customThe resulting reaction mixture
2. temperaturewas heated
3. temperatureunder reflux for 42 h
4. concentrationconcentrated in vacuo
5. customto remove methanol
6. additionThe residue was diluted with ethyl acetate (200 mL)
7. washThe organic phase was washed with a saturated aqueous sodium bicarbonate solution (1×100 mL)
8. washwashed with a saturated aqueous sodium chloride solution (1×100 mL)
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated in vacuo

ORD record

ord-1b10af1962a94ac58d60289e7b48c075

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06528543B1