Tetrahydrofuran → (2S,3S)-Methyl 2-(((benzyloxy)carbonyl)amino)-3-hydroxybutanoate

To a stirred solution of (2S,3S)-methyl 2-amino-3-hydroxybutanoate (2.5 g, 14.73 mmol) in a 1:1 mixture of tetrahydrofuran and water (50 mL), sodium bicarbonate (1.9 g, 22.10 mmol) was added and the mixture was cooled to 0° C. and to this benzyl chloroformate (2.76 g, 16.21 mmol) was added drop wise over a period of 30 minutes. The mixture was then stirred at the room temperature for 16 hours. The reaction mixture was diluted with ethyl acetate (25 mL), organic layers were separated, washed with brine (25 mL) and dried over sodium sulfate. Removal of solvents under vacuum afforded the crude product which has been purified by silica gel column chromatography (230-400 mesh) using a gradient of ethyl acetate in pet.ether. Yield: 3.4 g (86%) 1H NMR (400 MHz, DMSO-d6) δ: 1.09 (d, 3H), 3.89 (s, 3H), 3.99 (t, 1H), 4.01-4.06 (m, 1H), 5.00 (d, 1H), 5.04 (s, 2H), 7.30-7.40 (m, 5H), 7.63 (d, 1H). MS (ES) MH+: 268.1 for C13H17NO5.

1. additionwas added
2. additionwas added drop wise over a period of 30 minutes
3. customwere separated
4. washwashed with brine (25 mL)
5. dry with materialdried over sodium sulfate
6. customRemoval of solvents under vacuum

ORD-Eintrag

ord-9642ffd4e3c649dc916cfc0f016d6e31

Quelldatensatz

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08889671B2