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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture of triisopropyl borate (20 g, 110 mmol), dibromomethane (8.6 mL, 120 mmol), and tetrahydrofuran (150 mL) was added dropwise n-butyl lithium (2.6 M n-hexane solution, 39 mL, 100 mmol) over a period of 1.5 hours at −78° C., and then the reaction mixture was stirred for 1.5 hours at the same temperature. This mixture was then stirred for 2 hours at room temperature, after which it was cooled to 0° C., methanesulfonic acid (6.5 mL, 100 mmol) was added to the reaction mixture, and then the reaction mixture was stirred for 1 hour at room temperature. The mixture was cooled to 0° C., pinacol (12 g, 100 mmol) was added to the reaction mixture, and the reaction mixture was then stirred for 1 hour at room temperature. The reaction mixture was concentrated under a reduced pressure, after which the residue thus obtained was distilled under a reduced pressure (74-76° C., 8 mmHg) to obtain the title compound (16 g, 68%).

Herkunft & Nachweise