Acetic Acid → 3-Bromodibenzofuran

Participants

Reaction Conditions

Reaction Steps

NaNO2 (2.21 g, 32.05 mmol) was dissolved in 20 mL conc. H2SO4 in conical flask kept at 0° C. Solution of 2-aminodibenzofuran (5.3 g, 28.9 mmol) in minimum volume of glacial acetic acid was then slowly added to the flask so that temperature never raised above 5-8° C. and the mixture was stirred at 0° C. for another 1.5 h. 100 mL ether was added to the stirred mixture and precipitate of corresponding diazo salt immediately settled down. Brown color diazo salt was immediately filtered out and transferred to a flask containing CuBr (6.25 g, 43.5 mmol) in 150 mL 48% HBr. The flask was then placed in a water bath maintained at 64° C. and stirred for 2 h. After cooling down to room temperature, the dark color reaction content was filtered out and the precipitate was washed with water twice. Isolated solid was then flashed over Silica gel column with 5-10% DCM/Hexane to give 4.79 g final compound.

Provenance & Evidence