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

Participants

Reaction Conditions

Reaction Steps

To a solution of cyclopropylethynyl-trimethyl-silane (3.0 g, 22 mmol) in ether (20 mL) was added dropwise n-BuLi (8.6 mL, 21.7 mol, 2.5 M solution in hexane) at 0° C. The reaction mixture was stirred at ambient temperature for 24 h before dimethyl sulfate (6.85 g, 54.3 mmol) was added dropwise at −10° C. The resulting solution was stirred at 10° C. and then at 20° C. for 30 min each. The reaction was quenched by adding a mixture of sat. aq. NH4Cl and 25% aq. ammonia (1:3, 100 mL). The mixture was then stirred at ambient temperature for 1 h. The aqueous phase was extracted with diethyl ether (3×50 mL) and the combined organic layers were washed successively with 5% aqueous hydrochloric acid (100 mL), 5% aq. NaHCO3 solution (100 mL), and water (100 mL). The organics were dried over anhydrous NaSO4 and concentrated at ambient pressure. After fractional distillation under reduced pressure, trimethyl-(1-methyl-cyclopropylethynyl)-silane (1.7 g, 52%) was obtained as a colorless liquid. 1H NMR (400 MHz, CDCl3) δ 1.25 (s, 3H), 0.92-0.86 (m, 2H), 0.58-0.56 (m, 2H), 0.15 (s, 9H).

Provenance & Evidence