Dimethyl Sulfate → Trimethyl((1-methylcyclopropyl)ethynyl)silane

Participants

Reaction Steps

A 2.5 M solution of n-butyllithium in hexanes (96 mL, 240 mmol) was slowly added over 30 min. to a stirred solution of (cyclopropylethynyl)trimethylsilane (16.6 g, 120 mmol) in diethyl ether (50 mL) at room temperature. After complete addition, the reaction mixture was stirred at room temperature overnight. The reaction mixture was cooled to −78° C. and dimethyl sulfate (13.6 mL, 144 mmol) was added slowly over 30 min. to the stirred solution. After complete addition, the reaction mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The reaction mixture was diluted with diethyl ether (150 mL) and quenched with a saturated aqueous solution of ammonium chloride. The organic layer was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The product mixture was further distilled to remove the lower boiling diethyl ether, hexanes, and unreacted starting material to give trimethyl((1-methylcyclopropyl)ethynyl)silane (15.7 g, 86% yield) as a clear yellow liquid. 1H NMR (400 MHz, CDCl3) δ ppm 04-0.06 (m, 9H), 0.45 (d, J=2.42 Hz, 2H), 2.78 (d, J=2.42 Hz, 2H), and 1.13 (s, 3H).

Provenance & Evidence