Potassium Carbonate → Ether acetate

Participants

Reaction Conditions

Reaction Steps

1.0 g (3.1 mmol) of 3,6-dibromocarbazole, 1.8 g (6.2 mmol) of N-phenyl-9H-carbazol-3-boronic acid, and 457 mg (1.5 mmol) of tris(ortho-tolyl)phosphine were put into a 300 mL three-neck flask. To the mixture were added 20 mL of ethanol, 50 mL of toluene, and 20 mL (2.0 mol/L) of an aqueous solution of potassium carbonate. This mixture was stirred to be degassed while the pressure was reduced. To this mixture was added 70 mg (0.30 mmol) of palladium(II) acetate. This mixture was refluxed at 110° C. for 5 hours. After a predetermined time passed, the aqueous layer was extracted with toluene. The extract was combined with the organic layer and then washed with water and further with a saturated saline solution. The organic layer was dried with magnesium sulfate. This mixture was subjected to gravity filtration. The obtained filtrate was condensed to give an oily brown substance. The obtained oily substance was purified by silica gel column chromatography (a developing solvent was a mixed solvent of hexane:ether acetate=3:1) to give a white solid. This solid was recrystallized with chloroform/hexane to give 1.2 g of a white powder, which was the object of the synthesis, at a yield of 60%. A synthesis scheme of Step 2 is shown in (d-2) given below.

Provenance & Evidence