Hydrochloric Acid → B-(4-Cyano-3-ethylphenyl)boronic acid

Participants

Reaction Steps

3.66 ml of n-butylithium solution (1.6M in hexane) are added dropwise to a solution of 1.14 g of 4-bromo-2-ethylbenzonitrile in 20 ml of dry tetrahydrofuran at −78° C. After stirring at this temperature for 20 minute, 1.51 ml of triisopropyl borate are added. After 45 minutes, 12 ml of 1N HCl are added to the reaction mixture, which is warmed to room temperature. The phases are separated and the aqueous phase is extracted three more times with 100 ml of diethyl ether/tetrahydrofuran (1.1) each time. The combinred organic phases are dried with sodium sulphate, filtered and concentrated to 4 ml in vacuo. The remainig oil is mixed with 40 ml of pentane, and the precipitate which has separated out is filtered off with suction and washed twice with pentane. Drying under high vacuum results in the title compound as a yellow solid. Rt=3.27.

Provenance & Evidence