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

Temperature

10 °C

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, 3 H), 0.92-0.86 (m, 2 H), 0.58-0.56 (m, 2 H), 0.15 (s, 9 H).

1. additionwas added dropwise at −10° C
2. customThe reaction was quenched
3. additionby adding
4. additiona mixture of sat. aq. NH4Cl and 25% aq. ammonia (1:3, 100 mL)
5. stirringThe mixture was then stirred at ambient temperature for 1 h
6. extractionThe aqueous phase was extracted with diethyl ether (3×50 mL)
7. washthe combined organic layers were washed successively with 5% aqueous hydrochloric acid (100 mL), 5% aq. NaHCO3 solution (100 mL), and water (100 mL)
8. dry with materialThe organics were dried over anhydrous NaSO4
9. concentrationconcentrated at ambient pressure
10. distillationAfter fractional distillation under reduced pressure

ORD record

ord-9cff57ceac1240ffa4dfad3631c301ab

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08415387B2