N~2~-(tert-Butoxycarbonyl)-N-methoxy-N-methyl-D-alaninamide → 1350713-44-8

In a round-bottomed flask, [(R)-1-(methoxy-methyl-carbamoyl)-ethyl]-carbamic acid tert-butyl ester (3.00 g, 12.9 mmol) was dissolved in THF (100 ml). The solution was cooled to −16° C. (NaCl/ice bath) and methylmagnesium bromide (3.0 M in diethyl ether, 12.0 ml, 36.0 mmol) was added dropwise over 20 min. After the addition, the reaction mixture was allowed to warm slowly to room temperature overnight. The reaction mixture was cooled to 0° C., quenched with saturated aqueous NH4Cl and extracted with EtOAc (2×). The combined organic layers were washed with water and brine then dried over sodium sulfate, filtered and concentrated. The residue was chromatographed over silica gel with EtOAc/hexanes (gradient 0-20% EtOAc) to afford 2.21 g (91%) of ((R)-1-methyl-2-oxo-propyl)-carbamic acid tert-butyl ester as a white solid.

1. additionwas added dropwise over 20 min
2. additionAfter the addition
3. temperatureThe reaction mixture was cooled to 0° C.
4. customquenched with saturated aqueous NH4Cl
5. extractionextracted with EtOAc (2×)
6. washThe combined organic layers were washed with water and brine
7. dry with materialthen dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was chromatographed over silica gel with EtOAc/hexanes (gradient 0-20% EtOAc)

ORD record

ord-befa7136a08b4bc789e7cb67ad1d29fb

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658646B2