Reaktion #3713

Reaktionsgleichung

magnesium

(2RS,5SR)-2-dimethylaminomethyl-5-trifluoromethyl-cyclohexanone

3-trifluoromethyl-cyclohexanone

dimethylaminomethylene chloride

3-benzyloxy-1-bromobenzene

ammonium chloride

3-benzyloxy-1-bromobenzene

→

base ( 26 )

(1RS,2RS,5SR)-1-(3-benzyloxy-phenyl)-2-dimethylaminomethyl-5-trifluoromethyl-cyclohexanol

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

acetonitrile

ether

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was heated for one hour
2. 2
   Temperaturunder reflux
3. 3
   Temperaturwas thereafter cooled to 5°-10° C
4. 4
   workup.ADDITIONwere added at this temperature
5. 5
   Temperaturwas then cooled to 5°-10° C. again
6. 6
   Sonstigethe organic phase was separated off
7. 7
   Extraktionthe aqueous phase was extracted twice with 100 ml ether
8. 8
   TrocknenThe combined organic phases were dried over sodium sulphate
9. 9
   SonstigeAfter removing the solvent
10. 10
    workup.DISTILLATIONby distillation
11. 11
    workup.ADDITIONthe residue (60.6 g) was introduced on to an 8×50 cm column
12. 12
    Extraktionextracted with ethyl acetate/methanol

Vorschrift

43.9 g (167 mmole) 3-benzyloxy-1-bromobenzene, dissolved in 200 ml of dry tetrahydrofuran, were added drop-wise to 4.06 g (167 mmole) magnesium turnings in 40 ml of dry tetrahydrofuran so that the reaction mixture boiled gently. After the addition of 3-benzyloxy-1-bromobenzene was complete, the mixture was heated for one hour under reflux and was thereafter cooled to 5°-10° C. 30.8 g (139 mmole) (2RS,5SR)-2-dimethylaminomethyl-5-trifluoromethyl-cyclohexanone, prepared from 3-trifluoromethyl-cyclohexanone and dimethylaminomethylene chloride in acetonitrile, dissolved in 80 ml of dry tetrahydrofuran, were added at this temperature. The reaction mixture was allowed to stand overnight and was then cooled to 5°-10° C. again. The Grignard solution was decomposed by the addition of 150 ml of 20% ammonium chloride solution. The reaction mixture was diluted with 200 ml of ether, the organic phase was separated off and the aqueous phase was extracted twice with 100 ml ether. The combined organic phases were dried over sodium sulphate. After removing the solvent by distillation, the residue (60.6 g) was introduced on to an 8×50 cm column packed with silica gel and extracted with ethyl acetate/methanol. 27.8 g (50% theoretical) of base (26) were obtained.

Quelle