Hydrochloric Acid → 4-(piperazin-1-yl)-1H-indole

HRID 1779340Notes

Reaction equation

HRID 1779340 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[CH:4]=[CH:5][NH:6]2.Cl.Cl[CH2:13][CH2:14][NH:15][CH2:16][CH2:17]Cl.C(=O)([O-])[O-].[K+].[K+].Cl>C(O)CCC>[N:1]1([C:2]2[CH:10]=[CH:9][CH:8]=[C:7]3[C:3]=2[CH:4]=[CH:5][NH:6]3)[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 11430Potassium Carbonate2×HCID 522769Bis(2-chloroethyl)amine hydrochloride2×HCID 5834314-Aminoindole

Product 1

HCID 5945904-(piperazin-1-yl)-1H-indoleYield 22.4%

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent

Procedure

A suspension of 4-aminoindole (2.30 g, 0.017 moles), bischloroethylamine hydrochloride (3.49 g, 0.02 moles) and potassium carbonate (5.41 g, 0.02 moles) in butanol (50 ml) was heated at reflux under argon for 7 h. Further bischloroethylamine hydrochloride (0.70 g, 0.04 moles) and potassium carbonate (1.1 g 0.04 moles) was added, then the suspension was heated at reflux for 18 h. The solvent was evaporated in vacuo to give a brown gummy residue which was taken up into dilute hydrochloric acid (200 ml), washed with ethyl acetate (2×100 ml), made basic with potassium carbonate, extracted into dichloromethane (3×50 ml), dried (MgSO4) then evaporated in vacuo to give a white solid which was triturated with ethyl acetate and dried to give 4-(1-piperazinyl)indole (0.78 g, 0.0038 moles) as white crystals.

Workup

  1. temperaturewas heated
  2. temperatureat reflux under argon for 7 h
  3. temperaturethe suspension was heated
  4. temperatureat reflux for 18 h
  5. customThe solvent was evaporated in vacuo
  6. customto give a brown gummy residue which
  7. washwashed with ethyl acetate (2×100 ml)
  8. extractionextracted into dichloromethane (3×50 ml)
  9. dry with materialdried (MgSO4)
  10. customthen evaporated in vacuo
  11. customto give a white solid which
  12. customwas triturated with ethyl acetate
  13. customdried

Sources & evidence

ORD record
ord-43d43faf6d7f48b79b40bcfeaec8d767
Source dataset
uspto-grants-1997_05
Patent number
US05627177

Reaction notes

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