Ammonium Chloride → 5-bromo-1H,2H,3H-pyrrolo(2,3-b)pyridin-2-one

HRID 2300280Notes

Reaction equation

HRID 2300280 reaction equation
Br[C:2]1(Br)[C:10]2[C:5](=C[CH:7]=[C:8]([Br:11])[CH:9]=2)[NH:4][C:3]1=[O:12].[Cl-].[NH4+:15]>C1COCC1.[Zn]>[Br:11][C:8]1[CH:9]=[C:10]2[C:5](=[N:15][CH:7]=1)[NH:4][C:3](=[O:12])[CH2:2]2

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 13285276HCID 13285276, compound

Product 1

HCID 155040625-bromo-1H,2H,3H-pyrrolo(2,3-b)pyridin-2-one

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 3,3,5-tribromooxindole (5.0 g, 13.4 mmol) in fresh THF (100 mL) is stirred at room temperature and a saturated aqueous solution of ammonium chloride (100 mL) is added. The flask is placed in a water bath and activated zinc dust (15.0 g, 230 mmol) is added. The mixture is stirred for 20 min and the zinc is removed by filtration through a pad of diatomaceous earth. The organic layer is separated and the aqueous layer is extracted with THF (20 mL). The combined organic layers were washed with saturated brine solution, dried over anhydrous magnesium sulfate and the solvent removed under reduced pressure. The brown residue is triturated with water (20 mL) and the tan solid is collected by filtration and dried under vacuum to give 5-bromo-7-azaoxindole as a tan solid, 2.02 g (71%). 1H NMR (DMSO-d6) δ 11.13 (s, 1H), 8.15 (s, 1H), 8.76 (s, 1H), 3.57 (s, 2H). MS (AP −ve) 211 (100) (M−H).

Workup

  1. customThe flask is placed in a water bath
  2. additionis added
  3. customthe zinc is removed by filtration through a pad of diatomaceous earth
  4. customThe organic layer is separated
  5. extractionthe aqueous layer is extracted with THF (20 mL)
  6. washThe combined organic layers were washed with saturated brine solution
  7. dry with materialdried over anhydrous magnesium sulfate
  8. customthe solvent removed under reduced pressure
  9. customThe brown residue is triturated with water (20 mL)
  10. filtrationthe tan solid is collected by filtration
  11. customdried under vacuum

Sources & evidence

ORD record
ord-4f72b3d675364157a3e1a80b630d7f0c
Source dataset
uspto-grants-2002_12
Patent number
US06498176B1

Reaction notes

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