Dibromomethane → 2-(Bromomethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Temperature

0 °C

To a mixture of triisopropyl borate (20 g, 110 mmol), dibromomethane (8.6 ml, 120 mmol) and tetrahydrofuran (150 ml) was added dropwise n-butyllithium (2.6 M n-hexane solution, 39 ml, 100 mmol) at −78° C. (external temperature) over 1.5 hours. Then, the reaction mixture was stirred at the same temperature for 1.5 hours, and at room temperature for 2 hours. After the mixture was cooled at 0° C. (external temperature), to the reaction mixture was added methanesulfonic acid (6.5 ml, 100 mmol), and then, the reaction mixture was stirred at room temperature for 1 hour. After the mixture was cooled at 0° C. (external temperature), to the reaction mixture was added pinacol (12 g, 100 mmol), and then, the reaction mixture was stirred at room temperature for 1 hour. After the solvent was distilled off under reduced pressure, the resulting residue was distilled under reduced pressure (74-76° C., 8 mmHg) to obtain the title compound (16 g, 72 mmol, 68%).

1. waitat room temperature for 2 hours
2. stirringthe reaction mixture was stirred at room temperature for 1 hour
3. temperatureAfter the mixture was cooled at 0° C. (external temperature)
4. stirringthe reaction mixture was stirred at room temperature for 1 hour
5. distillationAfter the solvent was distilled off under reduced pressure
6. distillationthe resulting residue was distilled under reduced pressure (74-76° C., 8 mmHg)

ORD record

ord-c649b2fb37ff49dda303956685a879be

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07696347B2