Dimethyl Sulfate → (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidine

Participants

Reaction Steps

10.86 ml of dimethyl sulfate were added to a solution of 30 g of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine hydrochloride in a mixture of 36 ml of 20% w/v aqueous solution of sodium hydroxide and 470 ml of dioxane, and the resulting mixture was stirred at a temperature of between 22° C. and 23° C. for 1 hour. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure, and the resulting residue was extracted with 2 liters of ethyl acetate. The extract was washed with an aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate. The solution was then concentrated by evaporation under reduced pressure, until crystals emerged, and then 400 ml of diisopropyl ether were added to the mixture and the crystals which precipitated were collected by filtration, to give 23 g of the title compound as crystals, melting at 113°-114° C.

Provenance & Evidence