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

Temperature

0 °C

To the mixture of triisopropyl borate (20 g, 110 mmol), dibromomethane (8.6 ml, 120 mmol), and tetrahydrofuran (150 ml), n-butyllithium (a 2.6 M n-hexane solution, 39 ml, 100 mmol) was added dropwise at −78° C. (an outer temperature) for 1.5 hour, and then the reaction mixture was stirred at the same temperature for 1.5 hours. Subsequently, the obtained mixture was stirred at room temperature for 2 hours, and then was cooled to 0° C. (an outer temperature). To the reaction mixture, methanesulfonic acid (6.5 ml, 100 mmol) was added, and then the reaction mixture was stirred at room temperature for 1 hour. The obtained mixture was cooled to 0° C. (an outer temperature), pinacol (12 g, 100 mmol) was added to the reaction mixture, and then the reaction mixture was stirred at room temperature for 1 hour. The solvents were evaporated under reduced pressure from the reaction mixture, and then the obtained residue was distilled under reduced pressure (74-76° C., 8 mmHg), thereby obtaining the entitled compound (16 g, 72 mmol, 68%).

1. additionwas added dropwise at −78° C. (an outer temperature) for 1.5 hour
2. stirringSubsequently, the obtained mixture was stirred at room temperature for 2 hours
3. stirringthe reaction mixture was stirred at room temperature for 1 hour
4. additionwas added to the reaction mixture
5. stirringthe reaction mixture was stirred at room temperature for 1 hour
6. customThe solvents were evaporated under reduced pressure from the reaction mixture
7. distillationthe obtained residue was distilled under reduced pressure (74-76° C., 8 mmHg)

ORD record

ord-2614aadbfaf34fae9266a9e54ce59daf

Source dataset

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08524946B2