4-Nitrobenzoic Acid → [(1R,2R)-2-tert-butoxycarbonylamino-1-methyl-2-(3,4,5-trifluorophenyl)ethyl]4-nitrobenzoate

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Reaction Steps

In nitrogen atmosphere, diisopropylazodicarboxylate (6 mL) was dropwise added under ice-cooling to a THF solution (100 mL) of [(1R,2S)-2-hydroxy-1-(3,4,5-trifluorophenyl)propyl]carbamic acid tert-butyl ester (5.88 g), 4-nitrobenzoic acid (4.84 g), and triphenylphosphine (7.59 g). The resulting reaction solution was stirred at room temperature for 2 hr and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (toluene:ethyl acetate=97:3), and then the obtained powder was triturated with toluene-hexane to give 6.69 g of the title compound. The physical property values of this compound were as follows:

Provenance & Evidence