Dimethyl Sulfate → tert-Butyl [(2R)-1-(benzylamino)-3-methoxy-1-oxopropan-2-yl]carbamate

Temperatur

10 °C

To a stirred solution of 3.2 g (0.01 mol) of Intermediate 4 in 50 mL of toluene was added 0.61 g of tetrabutylammonium bromide and 5 ml of water. The resulting mixture was cooled to 10° C. and a solution of 2.4 g of sodium hydroxide in 2.5 ml of water was added dropwise maintaining the temperature below 10° C. Then, 5.54 g of dimethylsulfate was added dropwise maintaining the temperature below 10° C. After stirring at 10° C. for 2 hours, water (80 mL) was added and the reaction stirred at room temperature overnight. The layers were separated and the aqueous layer was washed twice with dichloromethane (50 mL). The combined organic phase was washed with sodium bicarbonate solution (2×30 mL) and brine. The solvent was removed under vacuum yielding 3.36 g of a pale red-oil. The oil was not purified and used directly in the following step.

1. temperaturemaintaining the temperature below 10° C
2. temperaturemaintaining the temperature below 10° C
3. stirringthe reaction stirred at room temperature overnight
4. customThe layers were separated
5. washthe aqueous layer was washed twice with dichloromethane (50 mL)
6. washThe combined organic phase was washed with sodium bicarbonate solution (2×30 mL) and brine
7. customThe solvent was removed under vacuum

ORD-Eintrag

ord-ab83edf02a53442f96d8bbfcd95bcdf5

Quelldatensatz

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08440861B2