Sulfuric Acid → 3-Tolylboronic acid

Participants

Reaction Steps

A solution of m-bromotoluene (25 g. 0.146 mol) in ether (200 ml) was added dropwise to magnesium (4.0 g, 0.17 mol) in ether (50 ml) at room temperature over a period of 3 hours under a nitrogen atmosphere. After the addition, the reaction mixture was stirred for 12 hours at room temperature. The Grignard reagent was added slowly to a solution of trimethyl borate (15.6 g, 17 ml, 0.15 mol) in ether (500 ml) over a period of 4hours at -78° C. and stirred for 12 hours at room temperature. The reaction mixture was hydrolyzed with 30% sulfuric acid (50 ml). The ether layer was separated, washed with water (3×250 ml) and dried over Na2SO4. The solvent was removed on a rotary evaporator and the solid obtained was recrystallized from water. M.P. 160°-161° C.

Provenance & Evidence