(3-Mercaptopropyl)trimethoxysilane → 1-(7,7-Dimethoxy-8-oxa-3-thia-7-silanonyl)-1,1,3,3-tetramethyl-3-vinyldisiloxane

Participants

Reaction Steps

1-(7,7-dimethoxy-8-oxa-3-thia-7-silanonyl)-1,1,3,3-tetramethyl-3-vinyldisiloxane was prepared according to the following process. Two and one-half moles (490 grams) of gamma mercaptopropyltrimethoxy silane was added to a 1-liter flask. A portion of a total quantity of one mole (186 grams) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane was added to the flask, resulting in the immediate formation of a bluegreen color and generation of heat. The flask was placed in a hood and stirred. The exotherm was measured at 75° C, subsided to about 55° C. and remained there for 10 minutes. The remaining 1,1,3,3-tetramethyl-1,3-divinyldisiloxane was added with no further exotherm. Gas/liquid chromotography revealed consumption of substantially all of the 1,1,3,3-tetramethyl-1,3-divinyldisiloxane reagent and the presence of mono- and diadduct products. The reaction product was distilled through a Vigreaux column to yield 60 g of approximately 95% pure product having a boiling point of 157° C. at 3.0 mm Hg.

Provenance & Evidence