Hydrochloric Acid → 4-(Trifluoromethyl)phenylboronic acid

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Reaction Steps

33 g (0.15 mol) of 4-bromotrifluoromethylbenzen was put into a 500-mL three-neck flask, and nitrogen substitution in the system was carried out. Then, 200 mL of tetrahydrofuran (THF) was added thereto, and the mixture was stirred. This mixture solution was stirred at −78° C., and 100 mL (0.16 mol) of n-butyllithium (1.6 mol/L) was dropped into the solution through a dropping funnel. After that, the obtained solution was stirred at the same temperature for 1 hour, and 22.3 mL (0.20 mol) of trimethyl borate was added to be stirred for about 12 hours while the reaction temperature was allowed to gradually increase to the room temperature. Then, 100 mL of dilute hydrochloric acid (1 mol/L) was added to the reaction solution, and the solution was stirred for 1 hour. A water layer of the mixture was extracted using ethyl acetate three times, the extracted solution and an organic layer were washed together one time using saturated saline, and the organic layer was dried with magnesium sulfate. The mixture was filtrated naturally to remove magnesium sulfate, and the filtrate was condensed to obtain a solid. The solid was washed with chloroform, whereby 15 g of a white solid, which was a target matter, was obtained with the yield of 54%.

Provenance & Evidence