Potassium Carbonate → 3-(Dibenzothiophen-4-yl)-9H-carbazole

Participants

Reaction Conditions

Reaction Steps

Into a 200 mL three-neck flask were placed 3.0 g (12 mmol) of 3-bromocarbazole, 2.8 g (12 mmol) of dibenzothiophene-4-boronic acid, and 0.15 g (0.5 mol) of tri(ortho-tolyl)phosphine, and the air in the flask was replaced with nitrogen. To this mixture were added 40 mL of toluene, 40 mL of ethanol, and 15 mL (2.0 mol/L) of an aqueous solution of potassium carbonate. In the flask, the mixture was degassed by being stirred under reduced pressure. After the degassing, the air in the system was replaced with nitrogen, and 23 mg (0.10 mmol) of palladium(II) acetate was added to this mixture, and then the mixture was refluxed at 80° C. for 4 hours. After the reflux, the mixture was cooled to room temperature, whereby a solid was precipitated. About 100 mL of toluene was added to the mixture in which the solid was precipitated, and the resulting mixture was heated and stirred, so that the precipitated solid was dissolved. While kept hot, the obtained suspension 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, so that 3.4 g of a white solid which was the object of the synthesis was obtained in 79% yield. The reaction scheme of Step 1 is illustrated in the following scheme (a-1).

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