2-Methyl-1-butene → (S)-2-methyl-3-[4-(4-trifluoromethyl-phenyl)-piperazin-1-yl]-propionic acid

(S)-2-Methyl-3-[4-(4-trifluoromethyl-phenyl)-piperazin-1-yl]-propionaldehyde (1.99 g; 6.6 mmol, prepared in accordance with Example 66) is suspended in a mixture of tert-butanol (48 mL) and water (12 mL); sodium dihydrogenphosphate (1.59 g; 13.3 mmol) and 2-methyl-butene (13.94 g; 199 mmol) are added and the resulting mixture is stirred until a solution is obtained. Sodium chlorite (1.12 g; 9.9 mmol) is added and the reaction is stirred at room temperature for one hour. The precipitate formed is filtered, is washed with water and is dried at 40° C. under 3 mbar. Aqueous sat ammonium chloride (50 mL) is added to the filtrate which is then extracted with dichloromethane (2×50 mL). The combined organic layers are washed with brine (50 mL) and concentrated under reduced pressure. The residue obtained is dried at 40° C. under 3 mbar. The enantiopure product is obtained as colourless solid (1.3 g; 4.1 mmol).

1. customis obtained
2. stirringthe reaction is stirred at room temperature for one hour
3. customThe precipitate formed
4. filtrationis filtered
5. washis washed with water
6. customis dried at 40° C. under 3 mbar
7. additionis added to the filtrate which
8. extractionis then extracted with dichloromethane (2×50 mL)
9. washThe combined organic layers are washed with brine (50 mL)
10. concentrationconcentrated under reduced pressure
11. customThe residue obtained
12. customis dried at 40° C. under 3 mbar
13. customThe enantiopure product is obtained as colourless solid (1.3 g; 4.1 mmol)

ORD-Eintrag

ord-13fb1e16d1894bcbb2bacbb075e312af

Quelldatensatz

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09096524B2