Propanoyl chloride, 2-(4-bromophenyl)- → (4R,5S)-3-[2-(4-Bromo-phenyl)-propionyl]-4-methyl-5-phenyl-oxazolidin-2-one

HRID 2092477Notes

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.[Br:19][C:20]1[CH:25]=[CH:24][C:23]([CH:26]([CH3:30])[C:27](Cl)=[O:28])=[CH:22][CH:21]=1>O1CCCC1>[Br:19][C:20]1[CH:21]=[CH:22][C:23]([CH:26]([CH3:30])[C:27]([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:28])=[CH:24][CH:25]=1

Participants

Conditions

Temperature: -78 °C

Procedure

(4R,5S)-(+)-4-Methyl-5-phenyl-2-oxazolidinone (0.348 g, 1.96 mmol) was dissolved in tetrahydrofuran (20 mL) and cooled to −78° C. n-Butyllithium (1.6M in hexanes; 1.64 mL, 2.62 mmol) was added, and the reaction was stirred for 1 hour at −78° C. 2-(4-Bromo-phenyl)-propionyl chloride (0.540 g, 2.18 mmol) in tetrahydrofuran (10 mL) was added, and the reaction was stirred for 30 minutes. The mixture was concentrated, and the residue was partitioned between EtOAc and water. The organic layer was separated, dried, and concentrated, and the crude material was purified by silica gel chromatography (0-25% EtOAc in hexanes) to give two diastereomers as separated products. Diastereomer A was the first product to come off the column, while Diastereomer B was the second product to come off the column.

Workup

additionwas added
stirringthe reaction was stirred for 30 minutes
concentrationThe mixture was concentrated
customthe residue was partitioned between EtOAc and water
customThe organic layer was separated
customdried
concentrationconcentrated
customthe crude material was purified by silica gel chromatography (0-25% EtOAc in hexanes)
customto give two diastereomers
customas separated products

Sources & evidence

ORD record: ord-e1b7945fe17f496a83b4abce318a0097
Source dataset: uspto-grants-2013_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08440707B2

Reaction notes

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