Potassium Hydroxide → 1H-Indol-5-amine, 3-(1,2,3,6-tetrahydro-1-methyl-4-pyridinyl)-

HRID 843758Notes

Reaction equation

HRID 843758 reaction equation
[OH-].[K+].[NH2:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[CH:7]2.[CH3:13][N:14]1[CH2:19][CH2:18][C:17](=O)[CH2:16][CH2:15]1>CO.O>[NH2:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[C:7]2[C:17]1[CH2:18][CH2:19][N:14]([CH3:13])[CH2:15][CH:16]=1

Participants

6

Reactant 3

HCID 14797Potassium HydroxideHCID 740491-Methyl-4-piperidoneHCID 788675-Aminoindole

Product 1

HCID 111488671H-Indol-5-amine, 3-(1,2,3,6-tetrahydro-1-methyl-4-pyridinyl)-Yield 48.9%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution of 1.29 gm (20 mMol) potassium hydroxide in 10 mL methanol were added 1.32 gm (10 mMol) 5-amino-1H-indole followed by 2.46 mL (20 mMol) 1-methyl-4-piperidone. The reaction mixture was then heated to reflux for 18 hours. The reaction mixture was cooled to ambient, diluted with 20 ml water and the precipitate collected by filtration. The solid was recrystallized from ethyl acetate:methanol to give 1.11 gm (48.9%) 5-amino-3-(1-methyl-1,2,3,6-tetrahydropyr-idin-4-yl)-1H-indole as a tan solid (m.p.=200-203° C.). The tan solid was subjected to flash chromatography, eluting with 100:20:0.5 dichloromethane:methanol:ammonium hydroxide, to give 0.99 gm 5-amino-3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indole as a cream colored solid (m.p.=212-215° C. (ethyl acetate:methanol)).

Workup

  1. temperatureThe reaction mixture was then heated
  2. temperatureto reflux for 18 hours
  3. temperatureThe reaction mixture was cooled to ambient,
  4. filtrationthe precipitate collected by filtration
  5. customThe solid was recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-0f153c0fa3ad41faa3193d9108c8d99b
Source dataset
uspto-grants-2002_04
Patent number
US06380201B1

Reaction notes

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