Hydrochloric Acid → 5,6,7,8,9,10-Hexahydro-7,10-iminocyclohept[b]indole

Participants

Reaction Steps

Method A, A solution of nortropinone hydrochloride (10.0 g, 61.9 mmol) and phenylhydrazine (7.7 g, 71.2 mmol) in 175 mL of 2-propanol was refluxed for 30 minutes, then it was allowed to cool to room temperature, saturated with hydrogen chloride, and heated under reflux for an additional 10 hours. The resulting solution was concentrated under reduced pressure to give a dark residue which was dissolved in methanol. Amberlite IRA-400 resin (pre-washed with methanol) was added until the pH exceeded 10. The mixture was filtered and the filter cake was washed with hot methanol to complete removal of the product from the resin. After the filtrate was treated with decolorizing carbon, it was filtered through a pad a diatomaceous earth and concentrated in vacuo. The residue was suspended in 50 mL of methylene chloride and the mixture was held at -5° C. for 24 hours. Filtration afforded 8.4 g (69%) of 5,6,7,8,9,10-hexahydro-7,10-iminocyclohept[b]indole which was converted into a hydrogen fumarate in ethanol, mp 208°-209° C. (dec); NMR (DMSO-d6) d 1.63 (1H, m), 1.90 (1H, m), 2.15-2.19 (2H, m), 2.68 (1H, d, J=16, 4 Hz), 3.31 (1H, dd, J=16.6, 4 7.28 (1H, d, J=8 Hz), 7.46 (1H, d, J=8 Hz), 11.10 (1H, s).

Provenance & Evidence