Water → 4-(6-Aminopyridin-3-yl)-1,3-dihydroindol-2-one

HRID 988137Notes

Reaction equation

HRID 988137 reaction equation
[Br-].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH:22]1[C:30]2[C:25](=[C:26]([C:31]3[CH:32]=[CH:33][C:34]([NH2:37])=[N:35][CH:36]=3)[CH:27]=[CH:28][CH:29]=2)[CH:24]=[CH:23]1.[OH2:38]>CC(O)(C)C.C(O)C.C(O)(=O)C.[Zn]>[NH2:37][C:34]1[N:35]=[CH:36][C:31]([C:26]2[CH:27]=[CH:28][CH:29]=[C:30]3[C:25]=2[CH2:24][C:23](=[O:38])[NH:22]3)=[CH:32][CH:33]=1

Participants

8

Reactant 3

HCID 962WaterHCID 21124087PyridiniumtribromideHCID 221354205-(1H-indol-4-yl)pyridin-2-amine

Product 1

HCID 221354324-(6-Aminopyridin-3-yl)-1,3-dihydroindol-2-oneYield 97%

Reagents, catalysts & solvents 4

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

Procedure

Pyridinium tribromide (90% (Aldrich), 3.7 g, 10.32 mmol) was added portion-wise over 10 minutes to a suspension of 5-(1H-indol-4-yl)-pyridin-2-ylamine (720 mg, 3.44 mmol) in 2-methyl-2-propanol (25 mL), ethanol (15 mL) and acetic acid (9 mL). The mixture was stirred at room temperature for 2 hours and then acetic acid (36 mL), water (1 mL) and zinc dust (3.2 g, 56.1 mmol) were added. Stirring was continued for 1.5 hours. Residual zinc dust was filtered and washed with methanol. The filtrate was concentrated and the syrupy residue was stirred in water (100 mL) overnight. The solid that formed was filtered, washed with water to remove zinc and pyridine salts and dried under high vacuum to give 750 mg (97%) of 4-(6-amino-pyridin-3-yl)-1,3-dihydroindol-2-one as a light brown solid.

Workup

  1. stirringStirring
  2. waitwas continued for 1.5 hours
  3. filtrationResidual zinc dust was filtered
  4. washwashed with methanol
  5. concentrationThe filtrate was concentrated
  6. stirringthe syrupy residue was stirred in water (100 mL) overnight
  7. customThe solid that formed
  8. filtrationwas filtered
  9. washwashed with water
  10. customto remove zinc and pyridine salts
  11. customdried under high vacuum

Sources & evidence

ORD record
ord-ca63b98d29aa425da3541d0eb32e1566
Source dataset
uspto-grants-2003_10
Patent number
US06635640B2

Reaction notes

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