Methyl iodide → (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidine

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Reaction Steps

0.07 ml of methyl iodide was added, whilst ice-cooling, to a solution of 0.6 g of (2S, 4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine [prepared as described in step (5) above] dissolved in 4.5 ml of dry dimethylformamide. The mixture was then stirred at 0° to 5° C. for 5 minutes and at room temperature for 20 minutes. At the end of this time, the reaction mixture was poured into a saturated aqueous solution of sodium bicarbonate and then extracted with ethyl acetate. The extract was washed with an aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and then the residue was subjected to column chromatography using a Lobar column (Merck, LiChroprep Si 60, size B), and 252 mg of the title compound, melting at 113°-114° C., were obtained as crystals from the fractions eluted with a 9:1 by volume mixture of ethyl acetate and methanol.

Provenance & Evidence