(S)-Methyl 2-amino-2-methylbutanoate hydrochloride → (R)-2-Amino-2-methyl-butyric acid methyl ester hydrochloride

In a 2-liter round-bottomed flask equipped with a condenser and a magnetic stirrer were placed 70 g of the (R)-N-chloroacetylisovaline obtained from the enzymatic resolution of racemic N-chloroacetylisovaline, 696 ml of water, and 696 ml of concentrated hydrochloric acid. The resulting mixture was heated at reflux for 2.25 hours. The mixture was then cooled to room temperature and the solvent was removed using rotary evaporation yielding a solid residue. the residue was washed with dry acetone and then dried in a vacuum oven at 40° C. yielding a crude product. The crude product was esterified with methanol using the above-described procedure for preparation of (S)-isovaline methyl ester hydrochloride to give 47.52 g of the corresponding (R)-isovaline methyl ester hydrochloride.

ORD record

ord-ad3d2c7c96e64680b3041c6b27016f99

Source dataset

uspto-grants-2003_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06566403B1