2-Bromopyridine → 4-pyridin-2-yl-1H-indole

HRID 1826719Notes

Reaction equation

HRID 1826719 reaction equation
[OH-].[Na+].CC1(C)C(C)(C)OB([C:11]2[CH:19]=[CH:18][CH:17]=[C:16]3[C:12]=2[CH:13]=[CH:14][NH:15]3)O1.Br[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][N:23]=1>[Pd].C1COCC1>[N:23]1[CH:24]=[CH:25][CH:26]=[CH:27][C:22]=1[C:11]1[CH:19]=[CH:18][CH:17]=[C:16]2[C:12]=1[CH:13]=[CH:14][NH:15]2

Participants

6

Reactant 3

HCID 79732-BromopyridineHCID 14798Sodium HydroxideHCID 113224711H-Indole-4-boronic acid, pinacol ester

Product 1

HCID 217698644-pyridin-2-yl-1H-indoleYield 71.2%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

Palladium catalyst Pd(PPh3)4 (714 mg, 0.6 mmol) and freshly prepared aqueous sodium hydroxide (2.47 g, 61.8 mmol in 22 mL of water) were added to a mixture of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indole (5 g, 20.6 mmol) and 2-bromopyridine (2 mL, 20.8 mmol) in THF (70 mL). The system was degassed and then purged three times with nitrogen. The mixture was stirred under nitrogen at 70° C. in an oil bath for 6 hours. It was then cooled to room temperature and 400 ml ethyl acetate was added. The organic layer was isolated, washed with brine, dried over anhydrous Na2SO4 and concentrated. The residue was triturated with dichloromethane to give 2.85 g (71%) of 4-pyridin-2-yl-1H-indole as a pale yellow solid.

Workup

  1. customThe system was degassed
  2. custompurged three times with nitrogen
  3. temperatureIt was then cooled to room temperature
  4. addition400 ml ethyl acetate was added
  5. customThe organic layer was isolated
  6. washwashed with brine
  7. dry with materialdried over anhydrous Na2SO4
  8. concentrationconcentrated
  9. customThe residue was triturated with dichloromethane

Sources & evidence

ORD record
ord-41e46b22be32457ba0018e6c84c41180
Source dataset
uspto-grants-2006_05
Patent number
US07053086B2

Reaction notes

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