Dimethyl Sulfate → (2S)-2-[(tert-Butoxycarbonyl)amino]-3-(3,5-difluorophenyl)propionic acid methyl ester

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Reaction Steps

(2S)-2-[(tert-butoxycarbonyl)amino]-3-(3,5-difluorophenyl)propanoic acid (I, 5.0 g, 0.017 moles, 1.0 equivalent) and potassium carbonate (2.5 g, 0.018 moles, 1.1 equivalent) are mixed in THF (100 mL). To this heterogeneous mixture is then added dimethyl sulfate (1.6 mL, 2.1 g, 0.017 moles, 1.0 equivalent) and the contents were then stirred at 20-25° overnight. Once the reaction is complete as measured by HPLC, ammonium hydroxide (10%, 20 mL) is added and allowed to stir for 1 hr at which time the contents are extracted with ethyl acetate (3×50 mL). The combined organic phases are washed with water (50 mL) and saline (50 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the title compound.

Provenance & Evidence