Acetic Acid → {4-[3-(1H-indol-3-yl)-pyrrolidine-1-yl]-1-phenyl-cyclohexyl}-dimethylamine

Participants

Reaction Steps

4-dimethylamino-4-phenylcyclohexanone (217 mg, 1 mmole) and 3-pyrrolidine-3-yl-1H-indole (186 mg, 1 mmole) were dissolved in a mixture of dry 1,2-dichloroethane (5 ml) and tetrahydrofuran (15 ml). Glacial acetic acid (57 μl, 1 mmole) and sodium sulfate (500 mg) were added to this mixture. After a reaction time of 15 minutes sodium triacetoxy boron hydride (318 mg, 1.5 mmole) was added to the reaction mixture and stirred for 4 days at RT. The reaction mixture was worked up by distilling off the solvent and adding saturated sodium hydrogen carbonate solution (20 ml) and water (20 ml). This aqueous phase was extracted with DCM (3×30 ml). The organic phase was dried with Na2SO4 and concentrated by evaporation. The chromatographic purification of the substance mixture was carried out on silica gel with methanol/30% aqueous ammonia (500:1). On dissolving the substance mixture in the solvent a colourless solid precipitated out, which was filtered off. This was identified by NMR spectroscopy as the non-polar diastereoisomer of {4-[3-(1H-indol-3-yl)-pyrrolidine-1-yl]-1-phenylcyclohexyl}-dimethylamine. The non-polar diastereoisomer was obtained in a yield of 79 mg (20%). The remaining substance mixture was purified by flash chromatography. The diastereoisomer mixture was obtained in a yield of 136 mg (35%).

Provenance & Evidence