Reaktion #1992257

Reaktionsgleichung

methyl 1,2,3,4,5,6-hexahydroazepino(4,5-b)indole-5-carboxylate

CH2Cl2

4,4-dimethyl-5-t-butyldimethylsilyloxyvaleraldehyde

azepine

→

title compound

Methyl 3-Benzyl-1,2,3,3a,4,5-hexahydro-4[2.2-dimethyl-3-(t-butyldimethylsilyloxy)propyl]-7H-pyrrolo(2,3-d)carbazole-6-carboxylate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstige(16 h)
2. 2
   Sonstigeat 20° C
3. 3
   SonstigeThe solvent was removed under vacuum (aspirator)
4. 4
   workup.ADDITIONTo this yellow solution was added 2.5 mL of benzyl bromide
5. 5
   Temperaturthe mixture heated
6. 6
   Temperaturat reflux for 18 h
7. 7
   SonstigeThe solvent was removed under vacuum (aspirator)
8. 8
   Sonstigethe residue triturated with pentane
9. 9
   Sonstigeto give a gummy solid
10. 10
    SonstigeThe pentane was removed by pipette
11. 11
    Sonstigethe gum triturated twice more with additional pentane
12. 12
    workup.ADDITIONTo this residue was added 100 mL of dry methanol and 6 mL 4 eq
13. 13
    Temperatur0.043 mol) of dry triethylamine and the whole heated
14. 14
    Temperaturat reflux for 3 h
15. 15
    TemperaturAfter cooling
16. 16
    Sonstigethe solvent was removed under vacuum (aspirator)
17. 17
    Waschenwashed with 10% NazCO3
18. 18
    TrocknenAfter drying over MgSO4 and concentration under vacuum (aspirator)
19. 19
    WaschenElution with the latter solvent mixture
20. 20
    Sonstigeafforded 5.6 g (70%

Vorschrift

To a solution of 3.5 g (14.3 mmol) of methyl 1,2,3,4,5,6-hexahydroazepino(4,5-b)indole-5-carboxylate in 175 mL of dry CH2Cl2 at 20° C. was added dropwise, over 2 min., 3.5 g (14.3 mmol, 1 eq) of 4,4-dimethyl-5-t-butyldimethylsilyloxyvaleraldehyde in 25 mL of dry CH2Cl2Stirring was continued overnight (16 h) at 20° C. The solvent was removed under vacuum (aspirator) and the residue taken up in CHCl3 (150 mL). To this yellow solution was added 2.5 mL of benzyl bromide and the mixture heated at reflux for 18 h. The solvent was removed under vacuum (aspirator) and the residue triturated with pentane to give a gummy solid. The pentane was removed by pipette and the gum triturated twice more with additional pentane. To this residue was added 100 mL of dry methanol and 6 mL 4 eq; 0.043 mol) of dry triethylamine and the whole heated at reflux for 3 h. After cooling, the solvent was removed under vacuum (aspirator) and the residue taken up in CH2Cl2 and washed with 10% NazCO3. After drying over MgSO4 and concentration under vacuum (aspirator), the residue was adsorbed on silica gel (20 g) and applied to the top of a silica gel column (200 g, as a slurry in ethyl ether/pentane 3:7). Elution with the latter solvent mixture afforded 5.6 g (70% overall based on the azepine) of the title compound. TLC: (Silica) Rf 0.60 (ethyl ether), detection, CAS, dark blue green with yellow center.

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