反应详情

A mixture containing 595 g (3.2 mol) of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 136 g (0.8 mol) of tetrachlorosilane and 2 ml of a 25% solution of phosphonitrile chloride in methylene chloride is stirred at room temperature for 8 hours. About 2.3 ml of tri-n-butylamine are then added to deactivate the phosphonitrile chloride. The reaction mixture is stirred for 30 minutes and then subjected to fractional distillation. About 216 g of 1,1,1-trichloro-3-vinyl-3,3-dimethyldisiloxane are obtained at 20° to 22° C. and at 2 mbar; about 53 g of 1,5-divinyl1,1,5,5-tetramethyl 3,3-dichlorotrisiloxane are obtained at 23° to 42° C. and at 2 mbar, and 9 g of a 1:1 mixture of 1,5divinyl-1,1,5,5-tetramethyl-3,3-dichlorotrisiloxane and 1,5-divinyl-1,1,5,5-tetramethyl-3-chloro-3-trimethylsiloxytrisiloxane are obtained at 42° to 72° C. and at 2 mbar. About 372 g of vinyldimethylchlorosilane are collected in the cold trap. The desired 1,5-divinyl-1,1,5,5-tetramethyl-3,3-bis(vinyldimethylsiloxy)trisiloxane is not obtained.

1. stirringThe reaction mixture is stirred for 30 minutes
2. distillationsubjected to fractional distillation