Ammonium Chloride → Carbamic acid, [(1S)-1-methyl-2-oxopropyl]-, 1,1-dimethylethyl ester (9CI)

HRID 497567Notes

Reaction equation

[CH3:1][Mg]Br.CON(C)[C:7](=[O:18])[C@@H:8]([NH:10][C:11](=[O:17])[O:12][C:13]([CH3:16])([CH3:15])[CH3:14])[CH3:9].[Cl-].[NH4+]>O1CCCC1>[CH3:9][C@H:8]([NH:10][C:11](=[O:17])[O:12][C:13]([CH3:14])([CH3:15])[CH3:16])[C:7](=[O:18])[CH3:1]

Participants

Conditions

Temperature: 0 °C

Procedure

Methyl magnesium bromide (3.0M solution in diethyl ether, 4.3 ml, 12.9 mmol) was added to a stirred solution of tert-butyl (1S)-2-[methoxy(methyl)amino]-1-methyl-2-oxoethylcarbamate (Tetrahedron: Asymmetry 1996, 7, 985) (1 g, 4.3 mmol) in anhydrous tetrahydrofuran (20 ml) at −60° C. under a nitrogen atmosphere. The mixture was allowed to warm to 0° C. and to then room temperature and was stirred at room temperature for 1 hour. Aqueous saturated ammonium chloride was added and aqueous phase was extracted with diethyl ether (2×76 ml). The combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine. The organic phase was then dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2), to afford the title compound as a colorless solid, 412 mg, 51% yield.

Workup

extractionaqueous phase was extracted with diethyl ether (2×76 ml)
washThe combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine
dry with materialThe organic phase was then dried (MgSO4)
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe residue was purified by column chromatography on silica gel
washeluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2)

Sources & evidence

ORD record: ord-7647e6e6d239447db7a1584d1964203e
Source dataset: uspto-grants-2005_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06949577B2

Reaction notes

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