Reaktion #940225

Reaktionsgleichung

9-Bromo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indole

trifluoroacetic acid

sodium hydroxide

Sodium borohydride

→

9-bromo-1,2,3,4,10,10a-hexahydro-pyrazino[1,2-a]indole

Ausbeute 68.2%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionwas extracted with dichloromethane
2. 2
   Waschenwashed with brine
3. 3
   Trocknendried with MgSO4
4. 4
   Sonstigethe solvent was evaporated

Vorschrift

9-Bromo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indole (3.5 g, 13.9 mmol) was dissolved in THF (15 mL) and trifluoroacetic acid (30 mL) and cooled to 0° C. Sodium borohydride (1 g, 27.9 mmol) was added in portions, the mixture was stirred for 90 min at room temperature and added to an ice/water mixture (150 mL). After addition of sodium hydroxide solution (28%, 35 mL) to render the mixture basic it was extracted with dichloromethane. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was evaporated. Chromatography on silica gel (dichloromethane/methanol/ammonia 180:10:1) yielded 9-bromo-1,2,3,4,10,10a-hexahydro-pyrazino[1,2-a]indole (2.4 g, 68%) as a yellowish solid, MS: m/e=252.0 (M+).

Quelle