(S)-4-Benzyl-2-oxazolidinone → (S)-4-Benzyl-3-(2-(4-fluorophenyl)acetyl)oxazolidin-2-one

Participants

Reaction Steps

Combine (S)-4-benzyl-2-oxazolidinone (22.9 g, 129 mmol) and tetrahydrofuran (120 mL). Cool in a dry-ice/acetone bath. Add dropwise a solution of n-butyl lithium (52 mL, 2.5 M, 130 mmol). After 15 minutes, slowly add a solution of 4-fluorophenylacetyl chloride (22.3 g, 129 mmol) in tetrahydrofuran (50 mL). Warm to ambient temperature. After 2 hours, quench the reaction mixture by the addition of a saturated aqueous sodium bicarbonate solution. Separate the layers and extract the aqueous layer with diethyl ether. Combine the organic layers, dry over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting wit 15% ethyl acetate/hexane. Combine the product containing fractions, evaporate, and recrytallize from diethyl ether/hexane to give (S)-4-benzyl-3-(4-fluorophenyl)acetyl-2-oxazolidinone.

Provenance & Evidence