Water → 4-Pyridin-2-yl-1,3-dihydroindol-2-one

HRID 1826720Notes

Reaction equation

HRID 1826720 reaction equation
[Br-].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[N:22]1[CH:27]=[CH:26][CH:25]=[CH:24][C:23]=1[C:28]1[CH:36]=[CH:35][CH:34]=[C:33]2[C:29]=1[CH:30]=[CH:31][NH:32]2.[OH2:37]>CC(O)(C)C.C(O)C.C(O)(=O)C.[Zn]>[N:22]1[CH:27]=[CH:26][CH:25]=[CH:24][C:23]=1[C:28]1[CH:36]=[CH:35][CH:34]=[C:33]2[C:29]=1[CH2:30][C:31](=[O:37])[NH:32]2

Participants

8

Reactant 3

HCID 962WaterHCID 21124087PyridiniumtribromideHCID 217698644-pyridin-2-yl-1H-indole

Product 1

HCID 221354314-Pyridin-2-yl-1,3-dihydroindol-2-oneYield 92%

Reagents, catalysts & solvents 4

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent2×HCID 702EthanolSolventHCID 6386tert-ButanolSolvent

Procedure

Pyridinium tribromide (90% (Aldrich), 15.4 g, 43.2 mmol) was added portion-wise over 10 minutes to a suspension of 4-pyridin-2-yl-1H-indole (2.8 g, 14.4 mmol) in 2-methyl-2-propanol (84 mL), ethanol (56 mL) and acetic acid (28 mL). The mixture was stirred at room temperature for 2 hours after which acetic acid (100 mL) was added. Stirring was continued for one hour and then water (0.5 mL) and zinc dust (9.4 g, 144 mmol) were added. Stirring was continued for another hour. Residual zinc dust was filtered and washed with methanol. The filtrate was concentrated and the syrupy residue was stirred in water (300 mL) overnight. The solid that formed was filtered, washed with water to remove zinc and pyridine salts and dried under high vacuum to give 2.8 g (92%) of 4-pyridin-2-yl-1,3-dihydroindol-2-one was obtained.

Workup

  1. additionwas added
  2. stirringStirring
  3. waitwas continued for another hour
  4. filtrationResidual zinc dust was filtered
  5. washwashed with methanol
  6. concentrationThe filtrate was concentrated
  7. stirringthe syrupy residue was stirred in water (300 mL) overnight
  8. customThe solid that formed
  9. filtrationwas filtered
  10. washwashed with water
  11. customto remove zinc and pyridine salts
  12. customdried under high vacuum

Sources & evidence

ORD record
ord-f96db42b41af4019a20a799d148088ae
Source dataset
uspto-grants-2006_05
Patent number
US07053086B2

Reaction notes

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