Hydrochloric Acid → 1,3-Divinyltetramethyldisiloxane

Beteiligte Stoffe

Reaktionsschritte

A methyl magnesium chloride solution is prepared by adding methylchloride to a mixture consisting of 1000 milliliters of tetrahydrofuran and 97.2 grams (4 mol) of magnesium in the form of magnesium shavings until the shavings have dissolved. About 400 grams (1.76 mol) of 1,3-dichloro-1,3-divinyl-1,3-dimethyldisiloxane is added dropwise to the methyl magnesium chloride solution with constant agitation and at a temperature between 25° and 75° C. About 1000 milliliters of paraffin oil having a boiling point of about 190° C. at 760 mm Hg (abs), is added, then about 700 milliliters of anhydrous tetrahydrofuran is distilled off until a bath temperature of 150° C. is obtained. The residue obtained from this distillation is mixed with 70 milliliters of water. About 280 milliliters of tetrahydrofuran having a water content of less than 0.5 percent by weight is recovered. After cooling, the residue obtained from the second distillation is mixed with 600 milliliters of water and 100 milliliters of 20 percent aqueous hydrochloric acid and from the organic phase is obtained 317 grams i.e. 94 percent of theoretical, of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane having a boiling point of from 138° to 139° C. and a purity in excess of 98 percent by weight.

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