Benzaldehyde → Valine, 3-hydroxy-N-(phenylmethyl)-(9CI)

A mixture of (S)-2-amino-3-hydroxy-3-methylbutanoic acid (18.6 g, 140 mmol), aqueous NaOH solution (2 mol/L, 70 mL) and benzaldehyde (14.56 g, 137 mmol) was stirred at 25° C. for 1 hour and cooled to 0° C. Then to the mixture was added sodium borohydride (3 g, 80 mmol) portion wise with the temperature maintained below 10° C. Then the mixture was warmed to 25° C. and stirred for another 12 hours. The aqueous layer was washed with DCM (30 mL×3) and the organic layer was discarded. The aqueous layer was cooled to 5° C., and adjusted to pH 1-2 with con. HCl. The mixture was stirred at 5° C. for 4 hours, and filtered to give the title compound as a white solid (18.8 g, 60%). The compound was characterized by the following spectroscopic data:

1. temperaturecooled to 0° C
2. temperaturemaintained below 10° C
3. temperatureThen the mixture was warmed to 25° C.
4. stirringstirred for another 12 hours
5. washThe aqueous layer was washed with DCM (30 mL×3)
6. temperatureThe aqueous layer was cooled to 5° C.
7. stirringThe mixture was stirred at 5° C. for 4 hours
8. filtrationfiltered

ORD-Eintrag

ord-1fd3a056fe384782bf2ee377ab335c77

Quelldatensatz

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09340538B2