Triethoxychlorosilane → 2-(Triethoxysilyl)thianthrene

Participants

Reaction Steps

A 3-neck 3 L flask was filled with magnesium turnings (35 g), THF (600 g) and chlorotriethoxysilane (278 g), and heated to reflux. Bromothianthrene solution from Example 4A was added to the flask in small portions. Grignard started instantly. The reaction was allowed to cool for 1 hour, after which magnesium salts were precipitated with heptanes (500 mL). The solution was filtered, followed by evaporation of volatiles by rotary evaporator. The material was distilled twice at <1 mbar, giving colorless 2-(triethoxysilyl)thianthrene (bp. 175 . . . 200° C., 234.2 g, 66.9% overall yield based on thianthrene, purity 99.5% by GC/MS) and bis(triethoxysilyl)thianthrene (bp. 200 . . . 225° C., 26.7 g, purity 94.6% by GC/MS, a mixture of 2,7- and 2,8-isomers, yield 5.3% by GC/MS).

Provenance & Evidence