Hydrochloric Acid → (4-(Phenanthren-9-yl)phenyl)boronic acid

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Reaction Conditions

Reaction Steps

Into a 100 mL three-neck flask, 2.0 g (11 mmol) of PnPBr obtained in the above Step 1 was put, and the air in the flask was replaced with nitrogen. Into the flask, 35 mL of tetrahydrofuran (THF) was added, and then this solution was stirred at −80° C. Into this solution, 8.3 mL (14 mmol) of n-butyllithium (1.6 mol/L hexane solution) was dropped by a syringe. After the dropping, this solution was stirred at the same temperature for 2 hours. After the stirring, 1.3 mL (11 mmol) of trimethyl borate was added to this solution, and the solution was stirred for 18 hours while the temperature of the solution was being increased to room temperature. Into this solution, hydrochloric acid (1.0 mol/L) was added, and then the solution was stirred for one hour. The organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and then with saturated saline, and magnesium sulfate was added to the organic layer so that moisture was adsorbed. The mixture was gravity-filtered, and the obtained filtrate was concentrated to give the objective white solid. This solid was recrystallized with ethyl acetate and hexane to give the objective substance as 2.5 g of white powdered solid in a yield of 74%.

Provenance & Evidence