(4R,5S)-(+)-4-Methyl-5-phenyl-2-oxazolidinone → (4R,5S)-3-[3-(4-Chlorophenyl)-propionyl]-4-methyl-5-phenyl-oxazolidin-2-one

HRID 1795181Notes

Reaction equation

[CH3:1][C@@H:2]1[C@H:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[O:5][C:4](=[O:13])[NH:3]1.C([Li])CCC.[Cl:19][C:20]1[CH:25]=[CH:24][C:23]([CH2:26][CH2:27][C:28](Cl)=[O:29])=[CH:22][CH:21]=1>O1CCCC1>[Cl:19][C:20]1[CH:21]=[CH:22][C:23]([CH2:26][CH2:27][C:28]([N:3]2[C@H:2]([CH3:1])[C@H:6]([C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=3)[O:5][C:4]2=[O:13])=[O:29])=[CH:24][CH:25]=1

Participants

Conditions

Temperature: -78 °C

Procedure

To a cooled (−78° C.) solution of 4-(R)-methyl-5-(S)-phenyl-oxazolidin-2-one, 31, (600 mg, 3.39 mmol) in anhydrous tetrahydrofuran (20 mL) is added n-butyl lithium (2.5 mL, 1.6M solution in hexanes, 4.07 mmol). The resulting solution is stirred at −78° C. for ninety minutes and then 3-(4-chloro-phenyl)-propionyl chloride (894 mg, 4.41 mmol) is slowly added. The solution is warmed to room temperature for thirty minutes and then the solvents removed under reduced pressure. The crude product is purified over silica (20:80 ethyl acetate:hexanes, Rf˜0.3) to afford 1.07 g (92% yield) of the desired compound as a colorless solid. 1H NMR (CDCl3 300 MHz) δ 0.91 (d, J=6.6 Hz, 3H), 3.01 (t, J=7.8 Hz, 2H), 3.18–3.40 (m, 2H), 4.77 (m, 1H), 5.67 (d, J=7.2 Hz, 1H), 7.18–7.48 (m, 9H). MS (ESI) m/z 344 (M+H+)

Workup

temperatureThe solution is warmed to room temperature for thirty minutes
customthe solvents removed under reduced pressure
customThe crude product is purified over silica (20:80 ethyl acetate:hexanes, Rf˜0.3)

Sources & evidence

ORD record: ord-6e99ae306e1145f7903bc7fa57040170
Source dataset: uspto-grants-2006_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07026335B2

Reaction notes

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