Tetrahydrofuran → 2-(2-(Ethylthio)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

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Reaction Conditions

Reaction Steps

A mixture of 14.1 g of 1-bromo-2-ethylsulfanylbenzene and 65 mL of THF was cooled to −70° C., and 44.7 ml of n-butyl lithium (1.63M hexane solvent) was added at a rate such that the internal temperature of the mixture was kept at −60° C. or less, and the mixture was stirred at −50° C. for 30 minutes. A mixture of 14 g of isopropoxyboronic acid pinacol ester and 5 mL of THF was added at a rate such that the internal temperature of the mixture was kept at −60° C. or less, and the mixture was heated to the room temperature. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, then dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was applied to a silica gel column chromatography to obtain 7.9 g of 2-ethylsulfanylphenylboronic acid pinacol ester.

Provenance & Evidence