67373-56-2

clear colorless to almost colorless liquid

mp 14–15 °C; bp 55–56 °C/10 mmHg; d 0.909 g cm?3.

Silylating reagent for the protection of 1? and 2? alcohols and N-silylation of amines and amides; used in the preparation of thexyldimethylsilyl triflate; formation of α-silyl hydrazones; formylation of polyfluoroalkyl halides. Thexyldimethylsilyl chloride (TDS-Cl) was first introduced as a more easily prepared alternative to the more commonly used t-butyldimethylsilyl chloride for the protection of alcohols.

To a mixture of dimethylchlorosilane (10 mL, 92 mmol) and AlCl3 (0.680 g, 5 mmol) at 25°Cwas added 2,3-dimethyl-2-butene (11 mL, 91 mmol). After stirring for 4 h at ambient temperature, the mixture was filtered and distilled to yield 15.2 g of TDS-Cl (93%).

Purify it by fractional distillation and store it in small aliquots in sealed ampoules. It is very sensitive to moisture and is estimated by dissolving an aliquot in excess of 0.1M NaOH and titrating with 0.1M HCl using methyl red as indicator [Szabó et al. Helv Chim Acta 67 2128 1984].