Réaction #56188

Équation de réaction

tetrahydrofuran

hydrochloric acid

borane

tetrahydrofuran

tetrahydrofuran

2-benzyl-5-phenyl-1,2,3,4-tetrahydropyrido[4,3-b]indole

→

trans-2-benzyl-2,3,4,4a,5,9b-hexahydro-5-phenyl-1H-pyrido[4,3-b]indole Hydrochloride

Solvants

acetic acid

Conditions de réaction

Traitement

1. 1
   Autrefitted with magnetic stirrer
2. 2
   workup.ADDITIONthermometer, condenser and addition funnel
3. 3
   Températuremaintained under a nitrogen atmosphere
4. 4
   workup.ADDITIONwas added a solution of 23.9 g
5. 5
   workup.ADDITIONThe addition
6. 6
   Températureto maintain the reaction temperature below 9° C
7. 7
   workup.ADDITIONWhen the addition
8. 8
   Températurewas heated
9. 9
   Températureto reflux
10. 10
    Températuremaintained at this temperature for one hour
11. 11
    AutreThe solvent was then evaporated in vacuo
12. 12
    Autreto afford a white solid mass which
13. 13
    TempératureThe resulting suspension was heated
14. 14
    Températureat reflux for one hour
15. 15
    Températurecooled
16. 16
    AutreEvaporation of tetrahydrofuran and part of the acetic acid
17. 17
    Autreresulted in precipitation of a white solid which
18. 18
    Autrewas separated by filtration
19. 19
    Lavagewashed with water
20. 20
    Filtrationfiltered
21. 21
    Lavagewashed with ethyl ether and air
22. 22
    Autredried
23. 23
    Autreto afford 16.7 g

Mode opératoire

To a solution of 0.140 moles of borane in 150 ml. of tetrahydrofuran stirred at 0° C. in a three-necked round bottom flask fitted with magnetic stirrer, thermometer, condenser and addition funnel, and maintained under a nitrogen atmosphere, was added a solution of 23.9 g. (0.071 mole) of 2-benzyl-5-phenyl-1,2,3,4-tetrahydropyrido[4,3-b]indole in 460 ml. of dry tetrahydrofuran. The addition was carried out at such a rate as to maintain the reaction temperature below 9° C. When the addition was completed the resulting mixture was heated to reflux and maintained at this temperature for one hour. The solvent was then evaporated in vacuo to afford a white solid mass which was suspended in 40 ml. of dry tetrahydrofuran and heated, slowly at first, with 180 ml. of a 1:1 by volume mixture of acetic acid and 5 N hydrochloric acid. The resulting suspension was heated at reflux for one hour, then cooled. Evaporation of tetrahydrofuran and part of the acetic acid resulted in precipitation of a white solid which was separated by filtration and washed with water. The solid was resuspended in tetrahydrofuran, filtered, washed with ethyl ether and air dried to afford 16.7 g. (63%) of the desired trans-isomer. M.P. 256°-260° C.

Source