2-Bromopyridine → Pyridine, 2,2'-(5-bromo-1,3-phenylene)bis-

HRID 2273504Notes

Reaction equation

HRID 2273504 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.Br[C:9]1[CH:14]=[C:13]([Br:15])[CH:12]=[C:11](Br)[CH:10]=1>CCCCC.C([Li])(C)(C)C.O1CCCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[C:11]1[CH:12]=[C:13]([Br:15])[CH:14]=[C:9]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=2)[CH:10]=1

Participants

6

Reactant 2

HCID 79732-BromopyridineHCID 122791,3,5-Tribromobenzene

Product 1

HCID 11007216Pyridine, 2,2'-(5-bromo-1,3-phenylene)bis-Yield 66%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolvent2×HCID 178446069HCID 178446069, compoundSolvent

Conditions

Temperature
-78 °C

Procedure

In a stream of argon, 89 mL of a 1.57M tert-butyllithium pentane solution was dissolved in 32 mL of tetrahydrofuran, and the solution was cooled to −78° C. 10.0 g of 2-bromopyridine was added dropwise to the solution, and the mixture was stirred for 1.5 hours. 42.5 g of dichloro(tetramethylethylenediamine)zinc was added to the mixture, and the temperature of the resultant mixture was elevated to room temperature, and the mixture was further stirred for 1 hour. To the resultant mixture, a suspension of 10.0 g of 1,3,5-tribromobenzene and 734 mg of tetrakis(triphenylphosphine)palladium in 64 mL of tetrahydrofuran was added. The obtained mixture was heated under reflux for 17 hours while being stirred. Then the obtained reaction mixture was cooled to room temperature, and was then distilled under a reduced pressure to remove all volatile materials. Water and chloroform were added to the concentrate, and the organic phase was separated and distilled to remove the solvent. The thus-obtained crude product was purified by silica gel chromatography using an ethyl acetate/hexane (2:8-1:1) mixed solvent to give 6.5 g of the target 3,5-di(2-pyridyl)bromobenzene as a yellow solid (yield: 66%).

Workup

  1. customwas elevated to room temperature
  2. stirringthe mixture was further stirred for 1 hour
  3. additionwas added
  4. temperatureThe obtained mixture was heated
  5. temperatureunder reflux for 17 hours
  6. stirringwhile being stirred
  7. customThen the obtained reaction mixture
  8. temperaturewas cooled to room temperature
  9. distillationwas then distilled under a reduced pressure
  10. customto remove all volatile materials
  11. additionWater and chloroform were added to the concentrate
  12. customthe organic phase was separated
  13. distillationdistilled
  14. customto remove the solvent
  15. customThe thus-obtained crude product
  16. customwas purified by silica gel chromatography
  17. additionmixed solvent

Sources & evidence

ORD record
ord-c686a1db51c64654a54b15cec2ba3e37
Source dataset
uspto-grants-2015_09
Patent number
US09120773B2

Reaction notes

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