Reaktion #1742

Reaktionsgleichung

4-(4-dimethylaminomethylphenyl)-cyclohexanone

sodium borohydride

→

trans-4-(4-Dimethylaminomethylphenyl)-cyclohexanol

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto react for 1.5 hours at ambient temperature
2. 2
   Sonstigeevaporated down in vacuo
3. 3
   workup.ADDITIONThe residue remaining is mixed with water
4. 4
   workup.STIRRINGstirred for 30 minutes at ambient temperature
5. 5
   Extraktionextracted several times with chloroform
6. 6
   TrocknenThe combined extracts are dried with sodium sulphate
7. 7
   Sonstigeevaporated down in vacuo
8. 8
   workup.ADDITIONwhich consists of a mixture of trans/cis-4-(4-dimethylaminomethyl-phenyl)-cyclohexanol (cis fraction <10%)
9. 9
   Sonstigeis purified by column chromatography (aluminium oxide neutral, activity stage III, ICN; petroleum ether/methylethyl ketone=5:1)
10. 10
    SonstigeWhite crystals are obtained

Vorschrift

To a solution of 11.1 g (0.048 mol) of 4-(4-dimethylaminomethylphenyl)-cyclohexanone in 100 ml of absolute methanol, which has been cooled to -10° C., is added 1.82 g (0.048 mol) of sodium borohydride in batches with stirring. The reaction mixture is allowed to react for 1.5 hours at ambient temperature and then evaporated down in vacuo. The residue remaining is mixed with water, acidified with concentrated hydrochloric acid, stirred for 30 minutes at ambient temperature, made alkaline with 50% sodium hydroxide solution and extracted several times with chloroform. The combined extracts are dried with sodium sulphate and evaporated down in vacuo. The residue remaining, which consists of a mixture of trans/cis-4-(4-dimethylaminomethyl-phenyl)-cyclohexanol (cis fraction <10%) is purified by column chromatography (aluminium oxide neutral, activity stage III, ICN; petroleum ether/methylethyl ketone=5:1). White crystals are obtained, melting point 63°-65° C.

Quelle