Reacción #92664

Ecuación de reacción

5,6α-epoxicholestan-3β-ol

tryptamine

1-Butanol

→

5α-Hydroxy-6β-(3-propylamino)-cholestan-3β-ol

Rendimiento 71.5%

Disolventes

methyl-tertbutyl-ether

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroequipped with a magnetic stirrer bar
2. 2
   Temperaturathe mixture heated
3. 3
   Temperaturato reflux for 40 h
4. 4
   Lavadowashed with water (5 vol) and with brine (5 vol)
5. 5
   Lavadoeluted with methyl-tertbutyl-ether (3 vol)
6. 6
   Otrothe solvent was removed under reduced pressure

Procedimiento

5,6α-epoxicholestan-3β-ol (8.9 g, 22.1 mmol, 1 eq) and tryptamine (7.1 g, 44.1 mmol, 2 eq) were charged in a round-bottomed flask equipped with a magnetic stirrer bar. 1-Butanol (70 ml, 5 vol) was added and the mixture heated to reflux for 40 h. The reaction mixture was cooled at r.t., diluted with methyl-tertbutyl-ether (5 vol) and washed with water (5 vol) and with brine (5 vol). The organic layer was passed through a silica pad (40 g) eluted with methyl-tertbutyl-ether (3 vol) then 10% Methanol/ethyl acetate (60 vol). Fractions of interest were pooled and the solvent was removed under reduced pressure to give 5α-Hydroxy-6β-(3-propylamino)-cholestan-3β-ol as a white solid (7.3 g, 59%). In same conditions, use of ethanol as solvent (40 vol) and Ca(OTf)2 as catalyst gave a 21% yield.

Fuente