Sodium Carbonate → (4S,5R)-4-(3,4-difluorophenyl)-2-oxo-oxazolidine-5-carboxylic acid methyl ester

Temperature

0 °C

To a solution of (2R, 3S)-3-amino-3-(3,4-difluorophenyl)-2-hydroxypropionic acid methyl ester (5.8 g, 25 mmol) in 250 mL tetrahydrofuran at 0° C. was added N,N-diisopropylethylamine (8.75 mL, 50 mmol) and triphosgene (2.48 g, 8.4 mmol). The reaction was stirred at 0° C. for 30 min when it was poured over ethyl acetate (200 mL) and saturated sodium carbonate solution (100 mL). The layers were separated, the organic layer washed with saturated sodium carbonate solution (1×100 mL), dried with magnesium sulfate, and concentrated in vacuo to provide a pale yellow oil. The material was triturated with 25% ethyl acetate/hexane from dichloromethane to provide (4S,5R)-4-(3,4-difluorophenyl)-2-oxo-oxazolidine-5-carboxylic acid methyl ester. The recovered mother liqour was passed through silica (50% ethyl acetate/hexane) to give an additional 1.1 g (4.8 g total, 18 mmol, 75%)

1. customThe layers were separated
2. washthe organic layer washed with saturated sodium carbonate solution (1×100 mL)
3. dry with materialdried with magnesium sulfate
4. concentrationconcentrated in vacuo
5. customto provide a pale yellow oil
6. customThe material was triturated with 25% ethyl acetate/hexane from dichloromethane

ORD record

ord-bca93155636f4ad99ebe9e7f95f99c65

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06255315B1