Methane → Ethyl 1,2,3,6-tetrahydroazepino[4,5-B]indole-5-carboxylate

HRID 37912

Reaction equation

HRID 37912 reaction equation
Cl.[NH2:2][CH2:3][CH2:4][C:5]1[C:13]2[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=2)[NH:7][CH:6]=1.Br[CH2:15][C:16](=O)[C:17]([O:19][CH2:20][CH3:21])=[O:18].C>C(O)C>[CH2:4]1[C:5]2[C:13]3[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=3[NH:7][C:6]=2[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:15][NH:2][CH2:3]1

Participants

5

Reactant 3

HCID 297MethaneHCID 66144Ethyl bromopyruvateHCID 67652Tryptamine hydrochloride

Product 1

HCID 57467979Ethyl 1,2,3,6-tetrahydroazepino[4,5-B]indole-5-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of tryptamine hydrochloride (1.96 g, 10 mmol), ethyl 3-bromopyruvate (1.67 mL, 1.2 equiv) and decolorizing charcoal (0.5 g) in absolute ethanol was heated to reflux under nitrogen overnight. TEA was added and the reaction mixture was heated to reflux for another 7.5 hours. After cooling, charcoal was removed by filtration and washed with ethanol. The filtrate was concentrated under vacuum and diluted with water (20 mL). It was then extracted by EtOAc (3×30 mL) and the combined organic layers were washed with brine and dried over MgSO4. Evaporation of solvent and recrystallization from DCM-Hexane gave the title compound (1.17 g). 1H-NMR (CDCl3): δ 10.49 (1 H, br s), 7.79 (1H, d), 7.43 (1H, d), 7.43 (1 H, d), 7.06 (2H, m), 5.27 (1H, br s), 4.29 (2H, q) 3.58 (2H, m), 3.17 (2H, m), 1.36 (3H, t); MS (ES): 257 (MH+).

Workup

  1. temperaturewas heated
  2. temperatureto reflux under nitrogen overnight
  3. additionTEA was added
  4. temperaturethe reaction mixture was heated
  5. temperatureto reflux for another 7.5 hours
  6. temperatureAfter cooling
  7. customcharcoal was removed by filtration
  8. washwashed with ethanol
  9. concentrationThe filtrate was concentrated under vacuum
  10. additiondiluted with water (20 mL)
  11. extractionIt was then extracted by EtOAc (3×30 mL)
  12. washthe combined organic layers were washed with brine
  13. dry with materialdried over MgSO4
  14. customEvaporation of solvent and recrystallization from DCM-Hexane

Sources & evidence

ORD record
ord-e9ef8ddee810448cb1d50790e723ab4a
Source dataset
uspto-grants-2013_09
Patent number
US08524704B2

Linked notes

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