Hydrochloric Acid → 4'-(9H-carbazol-9-yl)biphenyl-2-boronic acid

Participants

Reaction Conditions

Reaction Steps

Into 300 mL three-neck flask were put a mixed solution of 6.2 g (16 mmol) of 9-(2′-bromophenyl)-9H-carbazole and 100 mL of tetrahydrofuran (THF). After the solution was degassed under low pressure, the atmosphere in the flask was substituted by nitrogen. The solution was stirred at −78° C. for 20 minutes. After the stirring, 12 mL (19 mmol) of hexane solution of 1.55 mol/L of n-butyllithium was dripped with a syringe, and the solution was stirred at −78° C. for 2 hours. After the stirring, 4.0 mL of trimethyl borate was added and the mixture was stirred −78° C. for 1 hour, and then was stirred for about 24 hours while the temperature of the mixture was being gradually brought back to room temperature. After the stirring, to this solution was added 50 mL of 1M dilute hydrochloric acid, and the solution was stirred for 30 minutes at a room temperature. After the stirring, to this mixture was added ethyl acetate, and extraction with ethyl acetate was performed. After the extraction, the extracted solution was combined with the organic layer and washed with brine. After the washing, magnesium sulfate was added into the organic layer to dry the organic layer. After the drying, the mixture was subjected to suction filtration to give a filtrate. The obtained filtrate was concentrated and recrystallized with a mixture solvent of chloroform and hexane to give 3.2 g of a powdery white solid in a yield of 55%.

Provenance & Evidence