Benzyl chloroformate → 1-Benzyl 2-methyl (2S)-4-oxopyrrolidine-1,2-dicarboxylate

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Reaction Steps

(S)-Methyl 4-oxopyrrolidine-2-carboxylate HCl salt (9.4 g, 52.6 mmol) was dissolved in 1,4-dioxane (210 mL) and a solution of potassiumbicarbonate (13.2 g, 131.5 mmol) in DI-water (70 mL) was added at 0° C., followed by slow addition of benzylchloroformate (15 mL, 105.2 mmol). The mixture was then let warm up to room temperature and it was stirred overnight. The resulting crude mixture was concentrated down as much as possible on the rotovap and it was diluted with EtOAc and washed twice with saturated NaHCO3 and 10% citric acid and once with saturated NaHCO3 again and then with brine. The organic layer was dried over Na2SO4 and after filtration it was concentrated down on rotovap. The crude product was then purified on normal phase column chromatography (15% EtOAc/Hexanes). (14.6 g, 100%)

Provenance & Evidence