Methyl chloroformate → 2-((Methoxycarbonyl)amino)-3-methylbutanoic acid

Temperature

0 °C

To a solution of d-valine, (5.0 g) in 1N sodium hydroxide (42.7 mL) was added sodium carbonate (4.53 g). The solution was cooled to 0° C. and methyl chloroformate (0.289 mL) was added dropwise over 2 h and reaction mixture was stirred for 2 h at 0° C. White reaction mixture was diluted with enough H2O to form a colorless solution and washed with ethyl ether (3×30 mL). Aqueous layer was acidified to pH=2 with concentrated HCl to give a white precipitate that collected by filtration, washed with H2O and dried under high vacuum to give 2-Methoxycarbonylamino-3-methyl-butyric acid as a crystalline white solid (4.668 g). LCMS-ESI−: calc'd for C7H13NO4: 176.2 (M+H+). Found: 175.9 (M+H+).

1. customreaction mixture
2. customWhite reaction mixture
3. customto form a colorless solution
4. washwashed with ethyl ether (3×30 mL)
5. customto give a white precipitate
6. filtrationthat collected by filtration
7. washwashed with H2O
8. customdried under high vacuum

ORD record

ord-21fafb7ca61c4c13952b86c4e0a9159d

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08841278B2