反应详情

温度

-10 °C

3-Bromo-4-methoxybenzonitrile (3.0 g, 14.2 mmol, 1.0 eq) was dissolved in anhydrous tetrahydrofuran (10 mLs). The solution cooled at −10° C. and stirred while isopropylmagnesium chloride (17.7 mmol, 8.8 mLs, 2.0 M in THF, 1.25 eq.) was added. The mixture was stirred for 1 hour and then trimethyl borate (1.87 g, 17.7 mmol, 2.0 mL) was added dropwise. The mixture was allowed to warm slowly to room temperature for 1 hour. The solvent was evaporated and the residue was partitioned between 5% citric acid and ethyl acetate. The organic layer was separated, washed with water and brine, dried over anhydrous magnesium sulfate and concentrated to a minimum volume under reduced pressure. The residue was recrystallized from hexanes to give 5-cyano-2-methoxybenzeneboronic acid (2.48 g, 99%) as a fluffy white powder.

1. additionwas added
2. temperatureto warm slowly to room temperature for 1 hour
3. customThe solvent was evaporated
4. customthe residue was partitioned between 5% citric acid and ethyl acetate
5. customThe organic layer was separated
6. washwashed with water and brine
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated to a minimum volume under reduced pressure
9. customThe residue was recrystallized from hexanes