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

HRID 1168231Notes

Reaction equation

HRID 1168231 reaction equation
Br[C:2]1(Br)[C:10]2[C:5](=[N:6][CH:7]=[CH:8][CH:9]=2)[NH:4][C:3]1=[O:11].[NH4+].[Cl-]>C1COCC1.[Zn]>[NH:4]1[C:5]2=[N:6][CH:7]=[CH:8][CH:9]=[C:10]2[CH2:2][C:3]1=[O:11]

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 138640943,3-Dibromo-1H-pyrrolo[2,3-b]pyridin-2(3H)-one

Product 1

HCID 138640951,3-Dihydro-2H-pyrrolo(2,3-b)pyridin-2-one

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 3,3-dibromo-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one (2.0 g, 7.2 mmol) in THF (50 mL) was stirred at room temperature, and a saturated aqueous solution of NH4Cl was added. Activated zinc powder was added, and the reaction mixture was stirred for 2 h. The zinc was removed by filtration through a pad of diatomaceous earth, and the organic layer was separated. The aqueous layer was extracted with THF (10 mL), and the combined organic layers were dried over anhydrous MgSO4, filtered and evaporated. The residue was slurried in 10:1 CHCl3:MeOH (15 mL) and filtered through a pad of silica gel, and the filtrate was evaporated. The residue was triturated with water, and the solid was collected by filtration and dried under vacuum to give the title compound, 0.668 g (70%). 1H NMR (d6-DMSO) δ 10.94 (s, 1H), 8.02 (d, 1H, J=5.2 Hz), 7.52 (d, 1H, J=6.8 Hz), 6.90 (dd, 1H, J=6.8, 5.2 Hz), 3.53 (s, 2H). MS (AP−ve) 133 (100) (M−H).

Workup

  1. customThe zinc was removed by filtration through a pad of diatomaceous earth
  2. customthe organic layer was separated
  3. extractionThe aqueous layer was extracted with THF (10 mL)
  4. dry with materialthe combined organic layers were dried over anhydrous MgSO4
  5. filtrationfiltered
  6. customevaporated
  7. filtrationMeOH (15 mL) and filtered through a pad of silica gel
  8. customthe filtrate was evaporated
  9. customThe residue was triturated with water
  10. filtrationthe solid was collected by filtration
  11. customdried under vacuum

Sources & evidence

ORD record
ord-5fa5839ec00e49759319c768783393b2
Source dataset
uspto-grants-2003_09
Patent number
US06624171B1

Reaction notes

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