Oxygen → 2,7Dibromofluorenone

HRID 489496Notes

Reaction equation

HRID 489496 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-].C1(C)C=CC=CC=1>[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

6

Reactant 3

HCID 977OxygenHCID 14798Sodium HydroxideHCID 1400732,7-Dibromofluorene

Product 1

HCID 534201032,7DibromofluorenoneYield 77.5%

Reagents, catalysts & solvents 2

HCID 22266889Tetraammonium bromideCatalystHCID 1140TolueneSolvent

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 toluene (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 toluene layer was collected. The toluene layer was then subjected to acid washing, followed by water washing until its pH arose to 7. Toluene 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 a 1:1 (by weight ratio) mixed solvent of acetone and toluene (150 g) to afford 2,7-dibromofluorenone as yellow crystals (7.14 g).

Workup

  1. customInto a three-necked, 300-mL flask equipped with a stirrer
  2. additionwas charged
  3. additionwhile introducing air at a flow rate of 0.1 L/min
  4. customthe resulting toluene layer was collected
  5. washwashing
  6. distillationToluene was then distilled off
  7. customto recover crude crystals of 2,7-dibromofluorenone
  8. customThose crude crystals were recrystallized from a 1:1 (by weight ratio)
  9. additionmixed solvent of acetone and toluene (150 g)

Sources & evidence

ORD record
ord-9c72ca1e575d465898b27e4e85163e7f
Source dataset
uspto-grants-2005_12
Patent number
US06977313B2

Reaction notes

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