L-Valine → (2S)-2-((methoxycarbonyl)amino)-3-methylbutanoic acid

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Reaction Steps

L-Valine (140 g, 1.195 mol) is added to a stirred solution of 1 M sodium hydroxide (1.183 L, 1.183 mol). After complete dissolution, sodium carbonate (65.8 g, 621.4 mmol) is added followed by methyl chloroformate (122 g, 99.75 mL, 1.291 mol) at 0° C. over 40 minutes. The reaction mixture is stirred at rt for 3.5 hours, then washed with diethyl ether (3×200 ml). The aqueous layer is cooled to 0° C., and acidified to pH 1-2. The white solid formed is filtered on a Buchner, washed with cold water and dried to afford the title compound (2S)-2-(methoxycarbonylamino)-3-methyl-butanoic acid (140 g, 67%).

Provenance & Evidence