Imidazole → (S)-2-Iodomethyl-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

(S)-(−)-N-Boc-prolinol (10 g, 49.7 mmol), imidazole (6.76 g, 99.4 mmol) and triphenylphosphine (19.5 g, 74.5 mmol) were dissolved in diethyl ether (210 ml) and acetonitrile (80 ml) and the solution was cooled to 0° C. under an inert gas. Iodine (17.7 g, 70 mmol) was added in portions at this temperature. The yellow suspension was stirred for 15 h, and warmed to room temperature during this procedure. Addition of sodium thiosulfate solution (50 ml, 5 mol/l), stir for 5 min, the phases were separated. The aqueous phase was extracted with diethyl ether (2×100 ml) and the combined organic phases were washed with copper sulfate solution (30 ml, 5%) and sodium chloride solution (30 ml, saturated), dried over sodium sulfate and concentrated in vacuo. The crude product was purified by column chromatography (silica gel) with hexane/diethyl ether (6:1). Yield: 10.57 g (68%)

Provenance & Evidence