Phenylacetic Acid → (4S)-3-(2-Phenylacetyl)-4-(phenylmethyl)-2-oxazolidinone

Temperature

0 °C

A solution of 10 gm of phenylacetic acid (73 mmol) and 12.2 mL of triethylamine (87.6 mmol) in 200 mL of THF was cooled to −78° C. To this solution was added 9.8 mL of trimethylacetyl chloride (80 mmol) and the reaction was warmed to 0° C. and stirred for 1 hr. This solution was recooled to −78° C. (Solution #1) Meanwhile, to a solution of 14.2 gm of (S)-(−)-4-benzyl-2-oxazolidinone in 200 mL of THF at −78° C., was added 50 mL of a 1.6M solution of n-butyl lithium in THF (80 mmol)over 20 min. (Solution #2) After stirring for 20 min., this solution (#2) was slowly cannulated into the solution (#1) containing the mixed anhydride at −78° C. This reaction mixture was allowed to warm to room temperature and stirred for 2 hr. The reaction was quenched with a solution of saturated NH4Cl and extracted with ethyl acetate. The combined organic fractions were washed with water, sat. NaHCO3 solution, sat. NaCl solution, dried over MgSO4, filtered and concentrated. The crude product was purified by chromatograpy (silica, hexanes:ethyl; acetate=4:1) to give the title compound.

1. customwas recooled to −78° C.
2. stirringAfter stirring for 20 min.
3. temperatureto warm to room temperature
4. stirringstirred for 2 hr
5. customThe reaction was quenched with a solution of saturated NH4Cl
6. extractionextracted with ethyl acetate
7. washThe combined organic fractions were washed with water, sat. NaHCO3 solution, sat. NaCl solution
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe crude product was purified by chromatograpy (silica, hexanes:ethyl; acetate=4:1)

ORD record

ord-ea05a666f61a4eb09827c98a68f3dbaa

Source dataset

uspto-grants-2001_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06194458B1