Hydrochloric Acid → 2-Methyl-4-methylthiophenylboronic acid

Participants

Reaction Conditions

Reaction Steps

Add 1-bromo-2-methyl-4-methylsulfanyl-benzene (608 mg, 2.80 mmol) to diethyl ether (60 mL) and cool to −78° C. under a nitrogen blanket. Add t-BuLi (3.4 mL, 5.78 mmol) over a 15 minute period, stir for 2 minutes, add trimethyl borate ((MeO)3B, 340 μL, 2.99 mmol) over 2 minutes, stir for 15 minutes at −78° C. and then let warm to room temperature. Quench the reaction with saturated aqueous NH4Cl (7 mL), stir for 15 minutes, add 1M aqueous HCl (6 mL), stir for another 2 minutes and separate. Dry with Na2SO4, filter (wash the drying agent with ethyl acetate (3×20 mL)), and concentrate. Chromatograph the crude material on a SiO2 column with 20% ethyl acetate in hexanes to 5% methanol in ethyl acetate to give 267 mg of the title compound (52%).

Provenance & Evidence