Triisopropyl borate → (4-Methoxypyrimidin-5-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-bromo-4-methoxypyrimidine (0.460 g, 2.43 mmol) and triisopropyl borate (0.671 mL, 2.92 mmol) in 12 mL of THF at −70° C. was added butyllithium (1.6 m in hexanes, 1.83 mL, 2.92 mmol) dropwise. The addition took 15 minutes and the reaction turned light yellow. The reaction stirred for 30 minutes at −70° C. and was then allowed to warm up to −20° C. The reaction was quenched with ammonium chloride (sat.) and extracted with ethyl acetate. The aqueous layer was concentrated and NaCl (sat.) was added. The aqueous layer was extracted with 3/2 chloroform/iPrOH (3×). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated to give 166 mg of 4-methoxypyrimidin-5-ylboronic acid as a light yellow solid. ES+=155.2 (M+H)

Provenance & Evidence