Sulfuric Acid → (4-Methoxyphenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

100 ml of a solution of 10 g of p-bromoanisole in anhydrous diethyl ether is added dropwise under reflux to a suspension, under inert gas, of 1.3 g of magnesium turnings in 5 ml of anhydrous diethyl ether, and the mixture is left under reflux for 2 hours. The reaction medium is the poured into a solution of 9.02 ml of triethylborate in 60 ml of anhydrous ether cooled down to −70° C. After agitation for 1 hour at −70° C., then for 1 hour at ambient temperature, the solution is poured into a mixture containing 11 ml of sulphuric acid and 50 g of ice and water and agitation is carried out for 1 hour. The organic phase is extracted with 100 ml of a saturated aqueous solution of sodium bicarbonate, the aqueous phases are combined, reacidified with 6N hydrochloric acid, extracted with ether, dried and evaporated under reduced pressure, 3.9 g of expected product is obtained.

Provenance & Evidence