1,3-Butadiene → Silacyclopent-3-ene, 1-methyl-1-phenyl-

Beteiligte Stoffe

Reaktionsschritte

In a 500 mL two neck rb flask equipped with a reflux condenser, a Teflon covered magnetic stirring bar and a rubber septum was placed active magnesium powder (9.6 g, 0.4 mol), methylphenyldichlorosilane (38.2 g, 0.2 mol) and THF (300 mL). The reflux condenser was connected to a refrigeration unit. Ethylene glycol cooled to -20° C. was circulated through the reflux condenser. 1,3-Butadiene (15.1 g, 0.28 mol) was condensed at -78° C. into a volumetric flask which was sealed with a rubber septum. The 1,3-butadiene was transferred into the reaction via a cannula. The reaction mixture was stirred at rt for 24 h. Ether (2×100 mL) was added. The organic solution was decanted from the magnesium chloride salts. These were transferred to a sintered glass funnel and were washed with ether (100 mL). The combined organic solution was washed with water (2×50 mL), dried over anhydrous magnesium sulfate, filtered and the volatile solvents removed by evaporation under reduced pressure. The residue was purified by distillation through a 10 cm vacuum jacketed Vigreux column. The expected compound, bp 105°-107° C., 5 mm Hg, 42% yield, was collected.

Herkunft & Nachweise