Hydrogen Peroxide → (2R)-3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionic acid

Temperature

0 °C

A solution of 3-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionyl]-4(S)-isopropyl-oxazolidin-2-one (1.88 g, 4.72 mmol) in tetrahydrofuran (73 mL) and water (22 mL) cooled to 0° C. was treated with a 30% aqueous hydrogen peroxide solution (2.1 mL) and lithium hydroxide (394 mg, 9.4 mmol). The reaction was stirred at 0° C. for 1 h. At this time, the reaction was quenched with a saturated aqueous sodium sulfite solution (16 mL) followed by the addition of an aqueous solution of 0.5N sodium bicarbonate (50 mL). The tetrahydrofuran was then removed in vacuo. The residue was diluted with water (40 mL) and extracted with methylene chloride (3×20 mL). The aqueous layer was then acidified to pH=2 with a 5N aqueous hydrochloric acid solution and extracted with ethyl acetate (4×25 mL). The ethyl acetate layers were then dried over sodium sulfate, filtered, and concentrated in vacuo to afforded of 3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionic acid (928 mg, 70%) as a white solid: mp 75.1-78.3, C; [α]23589=−50.3° (c=0.100, chloroform); EI-HRMS m/e calcd for C14H16Cl2O2 (M) 286.0527, found 286.0535.

1. customAt this time, the reaction was quenched with a saturated aqueous sodium sulfite solution (16 mL)
2. additionfollowed by the addition of an aqueous solution of 0.5N sodium bicarbonate (50 mL)
3. customThe tetrahydrofuran was then removed in vacuo
4. additionThe residue was diluted with water (40 mL)
5. extractionextracted with methylene chloride (3×20 mL)
6. extractionextracted with ethyl acetate (4×25 mL)
7. dry with materialThe ethyl acetate layers were then dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo

ORD record

ord-a34d14fb23ca42f3ba5e094e039bd310

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06528543B1