Phthalimide potassium salt → (2s,4r)-1-p-Nitrobenzyloxycarbonyl-2-phthalimidomethyl-4-methanesulfonyloxypyrrolidine

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Reaction Conditions

Reaction Steps

A mixture of (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol p-toluenesulfonate (25 g: 47.3 mmole) and potassium phthalimide (17.52 g: 2 eq.) in dimethylformamide (250 ml) is stirred at 60° C. for 7 hours. The reaction mixture is poured into ice water and filtrated. The resulting precipitate is dissolved in ethyl acetate, washed with saturated brine, dried over magnesium sulfate, and concentrated in vacuo. The residue is recrystallized from methanol to give (2S,4R)-1-p-nitrobenzyloxycarbonyl-2-phthalimidomethyl-4-methanesulfonyloxypyrrolidine (18.76 g). Yield: 79%. mp. 121° to 123° C. NMR δ(CDCl3) ppm: 2.03 to 2.60(m, 2H), 3.02(s, 3H), 3.50 to 4.15(m, 4H), 4.40 to 4.63(m, 1H), 5.10, 5.29(ABq, J=15 Hz, 2H), 5.10 to 5.30(m, 1H), 7.46 (d, J=9 Hz, 1H), 7.57(d, J=9 Hz, 1H), 7.63 to 7.88(m, 4H), 8.20(d, J=9 Hz, 2H) IR ν (CHCl3) cm-1 : 1773, 1715, 1605.

Provenance & Evidence