Hydrochloric Acid → 3-Methoxy-2-methoxycarbonylamino-3-methyl-butyric acid

Participants

Reaction Steps

2-tert-Butoxycarbonylamino-3-methoxy-3-methyl-butyric acid was dissolved in dioxane (40 mL) and HCl (4N in dioxane, 5.4 mL, 21.6 mmol) was added at room temperature. The resulting solution was stirred at room temperature for 18 hours and the concentrated to dryness. The solid was dissolved in THF (14 mL) and cooled to 0° C. in an external ice/brine bath. Aqueous sodium hydroxide (6.25M, 1.9 mL, 11.76 mmol) and methyl chloroformate (0.5 mL, 5.88 mmol) were added at 0° C. Upon completion of the addition, the solution was removed from the ice bath and allowed to warm to room temperature, and stirred. After 18 hours, the crude reaction mixture was adjusted to pH 1 with 1N HCl and extracted twice with diethyl ether. The combined organic layers were washed with brine, dried with magnesium sulfate and concentrated to give 3-Methoxy-2-methoxycarbonylamino-3-methyl-butyric acid (0.653 g, 65%) as an off-white solid.

Provenance & Evidence