Sulfuric Acid → 3-Phenyllactic acid, (S)-

Temperatur

20 °C

L-Phenylalanine (10.00 g, 60.5 mmol) was added to a dilution of 8.88 g (90.5 mmol) of concentrated sulfuric acid in 110 g of water and then, at an inside temperature of 20° C., a mixture of 10.45 g (151.5 mmol) of sodium nitrite and 20 g of water was added over 5 hours. After addition, the mixture was stirred at 20° C. for 20 hours, 100 ml of t-butyl methyl ether was then added and, after 30 minutes of stirring at 20° C., the organic phase was separated (extract 1). Further, 50 ml of t-butyl methyl ether was added to the aqueous phase, the mixture was stirred at 20° C. for 30 minutes, and the organic phase was separated (extract 2). The extracts 1 and 2 were combined. The combined extract (116.5 g) contained 8.6 g of (2S)-2-hydroxy-3-phenylpropionic acid (yield 86%, optical purity 95.9% ee). The proton concentration (normality) in the reaction of this example was 1.7 mol/kg, the amount of the protonic acid was 3.0 equivalents (relative to L-phenylalanine), and the reaction temperature was 20° C.

1. additionwas added over 5 hours
2. additionAfter addition
3. stirringof stirring at 20° C.
4. customthe organic phase was separated
5. extraction(extract 1)
6. additionFurther, 50 ml of t-butyl methyl ether was added to the aqueous phase
7. stirringthe mixture was stirred at 20° C. for 30 minutes
8. customthe organic phase was separated
9. extraction(extract 2)
10. extractionThe combined extract (116.5 g)

ORD-Eintrag

ord-23c4a84d57fe4641be57dc04c183155c

Quelldatensatz

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07094926B2