Lithium Hydroxide → 3-Cyclopentyl-2-(4-methanesulfonyl-3-nitrophenyl)-propionic acid

Temperature

25 °C

A solution of 3-cyclopentyl-2-(4-methanesulfonyl-3-nitrophenyl)-propionic acid methyl ester (865 mg, 2.43 mmol) in tetrahydrofuran (6 mL) was treated with a 0.8M aqueous lithium hydroxide solution (4.6 mL, 3.65 mmol). The reaction mixture was stirred at 25° C. for 3 h. The reaction mixture was concentrated in vacuo to remove tetrahydrofuran. The resulting aqueous residue was diluted with water (25 mL) and then treated with a 1N aqueous hydrochloric acid solution (10 mL). The resulting aqueous layer was then extracted with ethyl acetate (2×50 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, ¼ hexanes/ethyl acetate) afforded 3-cyclopentyl-2-(4-methanesulfonyl-3-nitrophenyl)-propionic acid (723 mg, 87%) as a white foam. Analytical data indicated the presence of a small impurity; however, the 3-cyclopentyl-2-(4-methanesulfonyl-3-nitrophenyl)-propionic acid was used without further purification in subsequent reactions.

1. concentrationThe reaction mixture was concentrated in vacuo
2. customto remove tetrahydrofuran
3. additionThe resulting aqueous residue was diluted with water (25 mL)
4. additiontreated with a 1N aqueous hydrochloric acid solution (10 mL)
5. extractionThe resulting aqueous layer was then extracted with ethyl acetate (2×50 mL)
6. dry with materialThe combined organic layers were dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo

ORD record

ord-5f42cb29c2b2442dbad8e01ec0f821bb

Source dataset

uspto-grants-2001_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06320050B1