Sodium Hydroxide → rac-cis-3-(2-cyclopentyl-ethyl)-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]indol-6-ol

HRID 1109198Notes

Reaction equation

HRID 1109198 reaction equation
Cl.[CH:2]1([CH2:7][CH2:8][N:9]2[C@@H:17]3[C@@H:12]([C:13]4[CH:21]=[CH:20][CH:19]=[C:18]([O:22]C)[C:14]=4[CH2:15][CH2:16]3)[CH2:11][CH2:10]2)[CH2:6][CH2:5][CH2:4][CH2:3]1.[OH-].[Na+]>Br>[CH:2]1([CH2:7][CH2:8][N:9]2[C@@H:17]3[C@@H:12]([C:13]4[CH:21]=[CH:20][CH:19]=[C:18]([OH:22])[C:14]=4[CH2:15][CH2:16]3)[CH2:11][CH2:10]2)[CH2:6][CH2:5][CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 131718459rac-cis-3-(2-cyclopentyl-ethyl)-6-methoxy-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]indole hydrochloride

Product 1

HCID 131718461rac-cis-3-(2-cyclopentyl-ethyl)-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]indol-6-olYield 85.1%

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

5.80 g (0.0173 mol) of rac-cis-3-(2-cyclopentyl-ethyl)-6-methoxy-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]indole hydrochloride were dissolved in 0.18 l of 48% aqueous HBr and boiled under reflux for 5 hours. The mixture was poured on to ~200 g of ice and treated with 200 ml of 28% aqueous NaOH solution. The mixture was extracted three times with ethyl acetate, whereupon the organic phase was washed with saturated sodium chloride solution, dried with MgSO4, filtered and concentrated. By chromatography of the residue over silica gel with ethyl acetate there were obtained 4.20 g (85%) of oily rac-cis-3-(2-cyclopentyl-ethyl)-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]indol-6-ol.

Workup

  1. temperatureunder reflux for 5 hours
  2. extractionThe mixture was extracted three times with ethyl acetate
  3. washwhereupon the organic phase was washed with saturated sodium chloride solution
  4. dry with materialdried with MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-4a45b01658634c65bdf3cad10541d605
Source dataset
uspto-grants-1994_06
Patent number
US05318967

Reaction notes

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