Water → benzyl [(2S)-3-oxobutan-2-yl]carbamate

HRID 2275815Notes

Reaction equation

CON(C)[C:4](=[O:18])[C@@H:5]([NH:7][C:8](=[O:17])[O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)[CH3:6].[CH3:20][Mg]Br.C1COCC1.C1(C)C=CC=CC=1.O>C1COCC1>[O:18]=[C:4]([CH3:20])[C@@H:5]([NH:7][C:8](=[O:17])[O:9][CH2:10][C:11]1[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=1)[CH3:6]

Participants

Conditions

Temperature: -78 °C

Procedure

Under argon, 1000 mg of benzyl {(2S)-1-[methoxy(methyl)amino]-1-oxopropan-2-yl}carbamate (Example 148A, 3.8 mmol, 1 equivalent) were dissolved in 19.5 ml of THF and cooled to −78° C. At this temperature, 4 ml of 1.4 M methylmagnesium bromide solution in 1:3 THF/toluene (6 mmol, 1.5 equivalents) were added slowly. The mixture was stirred at −78° C. for 5 min and at RT for 1 h and allowed to stand at RT overnight. 0.27 ml of water was then added with ice cooling, and the mixture was concentrated. The residue was diluted with water and 1 N aqueous hydrochloric acid solution and extracted four times with ethyl acetate. The organic phase was washed with saturated aqueous sodium bicarbonate solution and with saturated aqueous sodium chloride solution, dried over magnesium sulphate, filtered and concentrated. This gave 813 mg (88% of theory; purity 90%) of the title compound.

Workup

waitto stand at RT overnight
concentrationthe mixture was concentrated
additionThe residue was diluted with water and 1 N aqueous hydrochloric acid solution
extractionextracted four times with ethyl acetate
washThe organic phase was washed with saturated aqueous sodium bicarbonate solution and with saturated aqueous sodium chloride solution
dry with materialdried over magnesium sulphate
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-8a1dd8e04e044e0c9fb4deb404043ff8
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09126998B2

Reaction notes

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