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 a 0.5N aqueous sodium bicarbonate solution (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 5N aqueous hydrochloric acid solution and extracted with ethyl acetate (4×25 mL). The combined organic 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 a 0.5N aqueous sodium bicarbonate solution (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 combined organic layers were then dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo

ORD record

ord-2949dd76f8a94db08795c1198ed585d2

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06610846B1