Carbazole → 9-[4-(benzoxazol-2-yl)phenyl]-9H-carbazole

Participants

Reaction Conditions

Reaction Steps

In a 100 mL three-neck flask were put 1.5 g (4.7 mmol) of 2-(4-iodophenyl)benzoxazole, 0.78 g (4.7 mmol) of 9H-carbazole, and 0.99 g (10 mmol) of sodium tert-butoxide. The atmosphere in the flask was replaced with nitrogen. To this mixture was added 15 mL of toluene. The resulting mixture was degassed under reduced pressure, and then the atmosphere in the flask was replaced with nitrogen. To this mixture were added 0.10 mL of a 10% hexane solution of tri(tert-butyl)phosphine and 0.030 g (0.48 mmol) of bis(dibenzylideneacetone)palladium(0). This mixture was stirred under a nitrogen stream at 110° C. for 11 hours. After that, toluene was added to this mixture, and this suspension was washed with 1M dilute hydrochloric acid, a saturated aqueous sodium hydrogen carbonate solution, and saturated brine in that order. After that, magnesium sulfate was added to the organic layer to dry it. Next, this mixture was suction filtered. The resulting filtrate was suction filtered through Celite (produced by Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855). The resulting filtrate was concentrated, followed by purification by silica gel column chromatography. As developing solvents for the column chromatography, a mixed solvent of a 1:1 ratio of toluene to hexane, and then toluene were used. The fraction obtained was concentrated to give a solid. This solid was recrystallized with a mixed solvent of chloroform and methanol to give 1.5 g of a white powdered solid in a yield of 89%.

Provenance & Evidence