Potassium Carbonate → Bidibenzo[b,d]thiophene

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Reaction Steps

Into a 500-mL three-neck flask were put 4.7 g (15 mmol) of 4-iododibenzothiophene, 3.6 g (16 mmol) of dibenzothiophene-4-boronic acid, and 91 mg (0.30 mmol) of tris(2-methylphenyl)phosphine, and the air in the flask was replaced with nitrogen. To this mixture were added 50 mL of toluene, 25 mL of ethanol, and 15 mL of an aqueous solution of potassium carbonate (2.0 mol/L). This mixture was degassed by being stirred while the pressure was reduced. To this mixture, 34 mg (0.15 mmol) of palladium(II) acetate was added. This mixture was stirred at 80° C. under a nitrogen stream for 3 hours to precipitate a solid. The precipitated solid was collected by suction filtration. The aqueous layer of the obtained filtrate was subjected to extraction with toluene, and the extracted solution and the organic layer were combined and washed with saturated brine. The organic layer was dried with magnesium sulfate, and this mixture was gravity-filtered. A solid obtained by concentrating the resulting filtrate and the solid collected by suction filtration were dissolved in approximately 100 mL of toluene. This solution was suction-filtered through Celite (Catalog No. 531-16855, produced by Wako Pure Chemical Industries, Ltd.), alumina, and Florisil (Catalog No. 540-00135, produced by Wako Pure Chemical Industries, Ltd). A solid obtained by concentrating the resulting filtrate was recrystallized from toluene/hexane to give 4.9 g of a white solid, which was an objective substance, in 90% yield. Synthesis Scheme (a-1) of Step 1 is shown below.

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