Oxygen → 2,7Dibromofluorenone

HRID 489493Notes

Reaction equation

HRID 489493 reaction equation
[O:1]=O.[Br:3][C:4]1[CH:16]=[CH:15][C:14]2[C:13]3[C:8](=[CH:9][C:10]([Br:17])=[CH:11][CH:12]=3)[CH2:7][C:6]=2[CH:5]=1.[OH-].[Na+]>[Br-].[NH4+].[NH4+].[NH4+].[NH4+].[Br-].[Br-].[Br-]>[Br:3][C:4]1[C:5](=[O:1])[C:6]2[C:14](=[CH:15][CH:16]=1)[C:13]1[C:8](=[CH:9][C:10]([Br:17])=[CH:11][CH:12]=1)[CH:7]=2

Participants

5

Reactant 3

HCID 977OxygenHCID 14798Sodium HydroxideHCID 1400732,7-Dibromofluorene

Product 1

HCID 534201032,7DibromofluorenoneYield 83.2%

Reagents, catalysts & solvents 1

HCID 22266889Tetraammonium bromideCatalyst

Procedure

Into a three-necked, 300-mL flask equipped with a stirrer, a molecular-oxygen-containing gas (air) inlet tube and a gas outlet tube (fitted with a condenser), 2,7-dibromofluorene (9.30 g, 0.029 mol) was charged, followed by its dissolution with “Cactus Solvent P-150” (product of Nikko Petrochemicals Co., Ltd.; 100 g). Subsequent to addition of tetraammonium bromide (0.24 g) and a 48% aqueous solution of sodium hydroxide (2.66 g), the resulting mixture was vigorously stirred at 60° C. for 2 hours while introducing air at a flow rate of 0.1 L/min. After completion of the stirring, the reaction mixture was allowed to stand, and the resulting “Cactus Solvent P-150” layer was collected. The “Cactus Solvent P-150” layer was then subjected to acid washing, followed by water washing until its pH arose to 7. “Cactus Solvent P-150” was then distilled off to recover crude crystals of 2,7-dibromofluorenone. The content of 2,7-dibromofluorene in the crude crystals at that time was 0%. Those crude crystals were recrystallized from N,N′-dimethylformamide (15 g) to afford 2,7-dibromofluorenone as yellow crystals (7.67 g).

Workup

  1. customInto a three-necked, 300-mL flask equipped with a stirrer
  2. additionwas charged
  3. dissolutionfollowed by its dissolution with “Cactus Solvent
  4. additionwhile introducing air at a flow rate of 0.1 L/min
  5. custom” layer was collected
  6. washwashing
  7. distillation“Cactus Solvent P-150” was then distilled off
  8. customto recover crude crystals of 2,7-dibromofluorenone
  9. customThose crude crystals were recrystallized from N,N′-dimethylformamide (15 g)

Sources & evidence

ORD record
ord-9b5daf01d0b845058bb5d33b2daa94f7
Source dataset
uspto-grants-2005_12
Patent number
US06977313B2

Reaction notes

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