Methyl iodide → (S)-Methyl 2-((tert-butoxycarbonyl)amino)-3-(4-nitrophenyl)propanoate

Participants

Reaction Steps

To a suspension of (S)-3-[4-nitrophenyl]-2-tert-butoxycarbonylamino-propionic acid (70.2 g, 226.2 mmol) and sodium carbonate (95 g, 1.13 mole) in DMF (500 mL) was added methyl iodide (70.4 mL, 1.13 mole) at room temperature. The suspension was stirred for 15 h at room temperature at which time TLC analysis of the mixture indicated the absence of starting material and the excess methyl iodide and some DMF were removed under high vacuum. Then, it was poured into water (2 L) and stirred at room temperature as a precipitate formed slowly over 72 h. The precipitated solids were collected by filtration and washed with water (2 L). After air and vacuum drying, 72 g (98% yield) of (S)-3-[4-nitrophenyl]-2-tert-butoxycarbonylamino-propionic acid methyl ester was isolated as a light yellow solid (mp 95-96° C.). ES(+)-HRMS m/e calcd. for C15H20N2O6 (M+H)+ 325.1400, obsd. 325.1404.

Provenance & Evidence