Hydrochloric Acid → Ethyl 3-bromo-2-hydroxypropanoate

Temperatur

0 °C

To a solution of sodium cyanoborohydride (17.72 g, 282.0 mmol) in anhydrous MeOH (160 mL) under an atmosphere of nitrogen was added ethyl bromopyruvate (32.25 mL, 256.4 mmol, 80-85%) in anhydrous MeOH (160 mL). The mixture was treated with 1N HCl in diethyl ether to pH 4 and stirred for 1 h at 0° C. The solvent was removed in vacuo, and the resulting slurry was partitioned between diethyl ether and saturated aqueous NH4Cl solution. The aqueous layer was extracted several times into diethyl ether, and the organic extracts were combined, dried over Na2SO4 and concentrated to a pale yellow oil. The oil was diluted with diethyl ether (300 mL) and chilled to −78° C. for 1 hour. The resulting precipitate was collected by filtration to afford the alcohol as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 5.99 (dd, J=1.2, 6.0 Hz, 1H), 4.43-4.39 (m, 1H), 4.21-4.08 (m, 2H), 3.69 (d, J=0.8 Hz, 2H), 1.23-1.18 (m, 3H).

1. customThe solvent was removed in vacuo
2. customthe resulting slurry was partitioned between diethyl ether and saturated aqueous NH4Cl solution
3. extractionThe aqueous layer was extracted several times into diethyl ether
4. dry with materialdried over Na2SO4
5. concentrationconcentrated to a pale yellow oil
6. additionThe oil was diluted with diethyl ether (300 mL)
7. temperaturechilled to −78° C. for 1 hour
8. filtrationThe resulting precipitate was collected by filtration

ORD-Eintrag

ord-78a85f56d7cf47d69b4ea043a9cb6c24

Quelldatensatz

uspto-grants-2009_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07476666B2