Sulfuric Acid → 5,6-Dimethoxy-1H-indole-3-ethylamine

HRID 1952871Notes

Reaction equation

HRID 1952871 reaction equation
OS(O)(=O)=O.[H-].[H-].[H-].[H-].[Li+].[Al+3:11].[CH3:12][O:13][C:14]1[CH:15]=[C:16]2[C:20](=[CH:21][C:22]=1[O:23][CH3:24])[NH:19][CH:18]=[C:17]2[CH2:25][C:26]#[N:27]>C1COCC1>[AlH3:11].[CH3:12][O:13][C:14]1[CH:15]=[C:16]2[C:20]([NH:19][CH:18]=[C:17]2[CH2:25][CH2:26][NH2:27])=[CH:21][C:22]=1[O:23][CH3:24]

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 21226445Aluminium lithium hydrideHCID 23301562HCID 23301562, compound

Product 2

HCID 14488Aluminum hydrideHCID 9074405,6-Dimethoxy-1H-indole-3-ethylamineYield 85.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent4×

Procedure

A solution of AlH3 in THF was prepared by dropwise addition of a solution of 0.52 ml (0.98 g, 10 mmol) of 100% H2SO4 in 4 ml of THF to a mixture of 0.76 g (20 mmol) of LiAlH4 and 20 ml of THF. Without removing the precipitated Li2SO4, a solution of 0.5 g (2.33 mmol) of 5,6-dimethoxy-3-indoleacetonitrile in 4 ml of THF was added over 30 min period. after stirring for another hour, the excess hydride was destroyed by the addition of small chips of ice. Most of the supernatant THF solution was decanted (setting aside most of the THF at this point greatly reduces emulsion formation in the subsequent extraction). The precipitated aluminum salts were treated with cold 20% NaOH, and the resulting cloudy solution was extracted with CHCl3. These extracts were combined with the THF solution, washed with NaCl solution, and dried over Na2SO4. The solvents were removed, and the residue was triturated with Et2-pentane. The crystalline product was washed with hot Et2O-Skelly B and dried, giving 0.44 g (83%) of pure 5,6-dimethoxytryptamine.

Workup

  1. customWithout removing the precipitated Li2SO4
  2. customthe excess hydride was destroyed by the addition of small chips of ice
  3. customMost of the supernatant THF solution was decanted (
  4. extractionsetting aside most of the THF at this point greatly reduces emulsion formation in the subsequent extraction)
  5. additionThe precipitated aluminum salts were treated with cold 20% NaOH
  6. extractionthe resulting cloudy solution was extracted with CHCl3
  7. washwashed with NaCl solution
  8. dry with materialdried over Na2SO4
  9. customThe solvents were removed
  10. customthe residue was triturated with Et2-pentane
  11. washThe crystalline product was washed with hot Et2O-Skelly B
  12. customdried

Sources & evidence

ORD record
ord-d333d02880e74ea0b1a826f423fc803a
Source dataset
uspto-grants-2000_09
Patent number
US06114373

Reaction notes

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