Triethylamine → (2S, 4R)-4-hydroxy-N-(4-nitrobenzyloxycarbonyl)proline methyl ester

To a clear solution of L-hydroxyproline methyl ester hydrochloride (27.2 g, 0.15 mol) and triethylamine (50 ml, 0.36 mol) in chloroform (500 ml) was added 4,6-dimethyl-2-(4-nitrobenzyloxycarbonylthio)pyrimidine (40.7 g, 0.13 mol) and then the resulting solution was stirred at room temperature for 12 hours, sequentially washed with H2O (200 ml), 0.5N NaOH (400 ml) and brine (200 ml) and dried (MgSO4). Concentration followed by silicagel column chromatography (Wakogel® C-300, ethyl acetate) afforded (2S, 4R)-4-hydroxy-N-(4-nitrobenzyloxycarbonyl)proline methyl ester (34.5 g, 70.9% yield) as an oil.

1. washsequentially washed with H2O (200 ml), 0.5N NaOH (400 ml) and brine (200 ml)
2. dry with materialdried (MgSO4)
3. concentrationConcentration

ORD-Eintrag

ord-659e3c238d034dea8a9a2a5f2ad9423d

Quelldatensatz

uspto-grants-1992_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05112818