Methyl chloroformate → N-(Methoxycarbonyl)-N-methyl-L-valine
Reaction equation
[CH3:1][CH:2]([CH3:9])[C@H:3]([NH:7][CH3:8])[C:4]([OH:6])=[O:5].[OH-].[Na+].C(=O)([O-])[O-].[Na+].[Na+].Cl[C:19]([O:21][CH3:22])=[O:20]>>[CH3:22][O:21][C:19]([N:7]([CH3:8])[C@@H:3]([CH:2]([CH3:9])[CH3:1])[C:4]([OH:6])=[O:5])=[O:20]Participants
5
Procedure
(2S)-3-Methyl-2-methylamino-butanoic acid (5 g, 38.12 mmol) is added to a stirring solution of sodium hydroxide (76.2 mL of 1 M, 76.24 mmol). After complete dissolution, sodium carbonate (2.1 g, 19.82 mmol) is added followed by methyl chloroformate (3.18 mL, 41.17 mmol) at 0° C. over 40 minutes. The reaction mixture is stirred at rt for 4 hours, and then washed with diethyl ether (2×75 ml). The aqueous layer is cooled to 0° C., acidified to pH 1-2 and extracted with CH2Cl2. The organic phase is dried over MgSO4, filtered and concentrated to dryness to give the title compound (2S)-2-[methoxycarbonyl(methyl)amino]-3-methyl-butanoic acid (5.12 g, 71%) as a clear oil.
Workup
- additionis added
- washwashed with diethyl ether (2×75 ml)
- temperatureThe aqueous layer is cooled to 0° C.
- extractionextracted with CH2Cl2
- dry with materialThe organic phase is dried over MgSO4
- filtrationfiltered
- concentrationconcentrated to dryness
Sources & evidence
- ORD record
- ord-0e144cec5c7d415a837449b592c9b4e0
- Source dataset
- uspto-grants-2014_07
- Patent number
- US08779156B2
Reaction notes
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