4-Bromoanisole → 4-Methoxyphenyl boric acid

Participants

Reaction Steps

13.09 g of 4-Bromoanisole was dissolved in 50 ml of tetrahydrofuran, and the solution was cooled to -78° C. with a dry ice-acetone freezing mixture, and 48 ml of m-butyllithium (as a 1.6 M hexane solution). The mixture was stirred for 10 minutes. A tetrahydrofuran solution of 32 ml of triisopropyl borate was added dropwise under cooling over the course of 30 minutes. The temperature of the solution was returned to room temperature, and it was stirred for 10 minutes. Ether was added to the reaction solution, and it was washed with a 10% aqueous solution of hydrochloric acid and water in this order. The solvent was evaporated, and the resulting solid was recrystallized from ether-hexane to give 7.18 g (yield 67.5%) of (4-methoxyphenyl)boric acid as colorless needles having a melting point of 157° to 159° C.

Provenance & Evidence