HCID 56949709, compound → HCID 56949710, compound

Participants

Reaction Steps

The crude isopropenyldiisopropylbromosilane (10.6 g) was treated with 75 mmol of lithium acetylide. The lithium acetylide was formed by saturating an anhydrous THF solution (at −78° C., 200 mL) with acetylene gas that had been passed through a −78° C. cold trap to remove acetone. No further drying of the acetylene gas was undertaken. Once the solution was presumed to be saturated (after 1 hour of flushing the gas through), the solution was treated with n-butyllithium (30 mL, 2.5 M in hexanes, 75 mmol) in a careful dropwise manner so as to maintain the temperature very close to −78° C. After this addition was completed, the isopropenyldiisopropylbromosilane was added as a concentrated solution (˜5 M) in anhydrous THF dropwise to the reaction mixture. The temperature was maintained for an additional 1 hour, then allowed to gradually warm to room temperature. The reaction was quenched by the slow addition of a small amount of saturated ammonium chloride (about 5 mL) and additional water (50 mL). Pentane (100 mL) was added, and the organic layer was separated. The aqueous layer was extracted a second time with pentane (50 mL), and the organic layer separated. The organic layers were washed with water (3×50 mL), dried over MgSO4, filtered, and concentrated on the rotary evaporator. No further purification was performed. Analysis of the liquid product was performed by GC-MS Analysis Method 2. This showed that the area under the peak corresponding to the desired product, (isopropenyldiisopropylsilyl)acetylene with a molecular weight of 180, was 87.34% of the total integrated area indicating a high purity.

Provenance & Evidence