Oxygen → 2,7Dibromofluorenone

Participants

Reaction Steps

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).

Provenance & Evidence