Boron trifluoride etherate → HCID 21332550, compound

Participants

Reaction Steps

To obtain 3-(bromopropyl)methyldiphenylsilane from allylmethyldiphenylsilane, a solution (150 ml) of 29.6 g (208.3 mol) of boron trifluoride etherate in dry tetrahydrofuran was added over a 1 hr period, with stirring, to 350 ml of a tetrahydrofuran solution of 119 g (0.50 mol) of allylmethyldiphenylsilane and 5.94 g (0.156 mol) of sodium borohydride. The reaction mixture was heated at reflux for 2.5 hrs and then 10 ml of methanol was added. Then, 27.3 ml (0.50 mol) of bromine and sodium methoxide solution (from 14.4 g, 0.625 mol of sodium and 300 mol of methanol) were added simultaneously at such a rate as to maintain a yellow color in the reaction mixture. The reaction temperature was kept at 25°-30° by means of an ice bath. The reaction mixture was poured into a mixture of 250 ml of 50% potassium carbonate and 250 ml of cyclohexane. The mixture was agitated until the strong yellow color faded. The layers were separated and the aqueous layer was extracted with three 100 ml portions of cyclohexane. The combined organic layers were washed with three 300 ml portions of water and with 150 ml of saturated sodium chloride, dried over potassium carbonate, and distilled to give 79 g (49.5%) of (3-bromopropyl) methyldiphenylsilane, mp.176°-210° (0.3 mm).

Provenance & Evidence