Potassium Carbonate → 4-(9H-Carbazol-3-yl)dibenzofuran

Participants

Reaction Conditions

Reaction Steps

Into a 200 mL three-neck flask were placed 2.0 g (8.1 mmol) of 3-bromocarbazole, 1.7 g (8.1 mmol) of dibenzofuran-4-boronic acid, and 150 mg (0.5 mol) of tri(ortho-tolyl)phosphine, and the air in the flask was replaced with nitrogen. To this mixture were added 20 mL of toluene, 20 mL of ethanol, and 15 mL (0.2 mol) of an aqueous solution of potassium carbonate (2.0 mol/L). In the flask, the mixture was degassed by being stirred under reduced pressure. After 23 mg (0.10 mmol) of palladium(II) acetate was added to this mixture, the mixture was refluxed at 80° C. After the reflux, the mixture was cooled to room temperature, and then the obtained solid was collected by suction filtration. The collected solid was dissolved in 100 mL of toluene, and this solution was filtered through Celite (produced by Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855), Florisil (produced by Wako Pure Chemical Industries, Ltd., Catalog No. 540-00135), and alumina. The solid obtained by concentration of the obtained filtrate was recrystallized from toluene/hexane, so that 2.3 g of a white solid was obtained in 85% yield. The synthesis scheme of Step 1 is illustrated in the formula (a-2).

Provenance & Evidence