Sodium hydride → (2R,3R)-2,3-epoxybutyric acid N-tert.-butoxycarbonylmethyl-N-p-methoxybenzylamide

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Reaction Steps

A solution of 2.21 g of (2R,3R)-2,3-epoxybutyric acid p-methoxybenzylamide in 100 ml of THF is added dropwise to a mixture, stirred at 0° under an argon atmosphere, of 550 mg of sodium hydride dispersion (55-60% in oil) and 1.52 ml of bromoacetic acid tert.-butyl ester in 25 ml of THF. The reaction mixture is heated to room temperature and stirred for a further 1 hour (reaction monitored by thin-layer chromatography). Total reaction time: 90 minutes. The insoluble portions are filtered off and washed with THF and the combined filtrates are concentrated by evaporation. The resulting crude product is purified by chromatography over 150 g of silica gel (system: toluene, toluene/ethyl acetate 80:20). Concentration of the pure fractions by evaporation yields the amorphous title compound.

Provenance & Evidence