Sodium Carbonate → 5-Oxazolidinecarboxylicacid,2-oxo-,methylester(8CI,9CI)

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 svas triturated with 25% ethyl acetate/hexane to provide (4S,5R)-4-(3,4-difluorophen)fl)-2-oxo-oxazolidine-5-carboxylic acid methyl ester. The recovered mother liquor was passed through silica (50% ethyl acetate/hexane) to give additional product.

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 svas triturated with 25% ethyl acetate/hexane

ORD record

ord-2a0a5bda632f4a9880c06f6fac1acb9a

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06228870B1