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-27f4bfb039c147f29bb943cecec142cd

Quelldatensatz

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09187495B2