Reaktion #749097

Reaktionsgleichung

cesium carbonate

ethyl 5-bromo-8-cyano-9H-carbazole-2-carboxylate

(R)-benzyl piperidin-3-ylcarbamate

→

(R)-ethyl 5-(3-(benzyloxycarbonylamino)piperidin-1-yl)-8-cyano-9H-carbazole-2-carboxylate

Ausbeute 37.0%

Lösungsmittel

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was purged with nitrogen
2. 2
   TemperaturThe mixture was cooled to rt
3. 3
   Einengenconcentrated
4. 4
   SonstigeThe residue was partitioned between EtOAc and NaHCO3 (aq)
5. 5
   WaschenThe organic phase was washed with brine
6. 6
   Sonstigedried
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe residue was purified by column chromatography (
9. 9
   Wascheneluting with a gradient from 80:20 to 60:40 hexane-EtOAc)

Vorschrift

Step 2 A mixture of cesium carbonate (0.960 g, 2.95 mmol), (RS)-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (0.059 g, 0.095 mmol), tris(dibenzylideneacetone)dipalladium (0.058 g, 0.063 mmol), ethyl 5-bromo-8-cyano-9H-carbazole-2-carboxylate (0.85 g, 2.105 mmol) and (R)-benzyl piperidin-3-ylcarbamate (0.493 g, 2.105 mmol) was suspended in 1,4-dioxane (70 mL). The mixture was purged with nitrogen and heated at 100° C. for 18 h. The mixture was cooled to rt and concentrated. The residue was partitioned between EtOAc and NaHCO3 (aq). The organic phase was washed with brine, dried and concentrated. The residue was purified by column chromatography (eluting with a gradient from 80:20 to 60:40 hexane-EtOAc) to provide (R)-ethyl 5-(3-(benzyloxycarbonylamino)piperidin-1-yl)-8-cyano-9H-carbazole-2-carboxylate as a brown solid (0.68 g, 70% purity, 37% yield), used without further purification. Mass spectrum m/z 497.2 (M+H)+.

Quelle