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

Participants

Reaction Steps

5.67 g (60 mmol) of methyl chloroformate (Fluka, Buchs, Switzerland) are added to 7.0 g (60 mmol) of L-valine in 100 ml of 2N NaOH and 30 ml of dioxane (→exothermic reaction), and this mixture is subsequently stirred at RT for 18 h. The reaction mixture is extracted with methylene chloride, and the aqueous phase is acidified with 27 ml of 4N HCl and once again extracted with methylene chloride. Drying and evaporating the latter methylene chloride phase affords the title compound: tRet (I)=7.2 min; 1H-NMR (200 MHz, CD3OD): 0.96 (t, J=7 Hz, 6H), 2.16 (m, 1H), 3.67 (s, 3H), 4.06 (m, 1H), 7.07 (d, J=8 Hz, HNpartially exchanged).

Provenance & Evidence