Ammonium Chloride → HCID 86663260, compound

Participants

Reaction Conditions

Reaction Steps

In an oven-dried 250-mL round bottom flask, 4.12 g (42.0 mmol) of trimethylsilylacetylene was dissolved in 45 mL of anhydrous THF. The solution was cooled to 0° C., then n-butyllithium (14.8 mL, 37 mmol, 2.5 M in hexane) was added dropwise. Stirring was continued for 1 hr and the colorless solution was allowed to warm to room temperature. In a second oven-dried 500-mL round bottom flask, 3,3,3-trifluoropropyltrichlorosilane (8.1 g, 35 mmol) was dissolved in anhydrous THF (35 mL). The first reaction mixture was added to the second solution dropwise over 1 hr, followed by stirring for 5 hrs. The new reaction mixture was cooled to 0° C., then isopropyllithium (123 mL, 86 mmol, 0.7 M in pentane) was added dropwise, and the solution was allowed to warm to room temperature over 12 hrs. The entire mixture was poured into 150 mL of a dilute solution of ammonium chloride, and hexane (100 mL) was added. The organic layer was separated, and the aqueous layer was extracted a second time with hexane (20 mL). The organic layers were combined, washed with water (3×20 mL), dried over magnesium sulfate, filtered, and concentrated under vacuum. The trimethylsilyl-capped product was purified by column chromatography on silica gel using hexane as an eluant (Rf˜0.6 in hexane), yielding 7.7 g of a colorless liquid. The trimethylsilyl group was removed by dissolving the product in THF (20 mL) and adding methanol (20 mL) and 3 drops of a 15% sodium hydroxide solution, followed by stirring for 30 minutes. The crude product was isolated, then flushed through a thin pad of silica using hexane and concentrated under vacuum to yield 4.9 g (21 mmol, 60% from the starting silane) of a colorless liquid. Analysis of the colorless product provided the following data: 1H-NMR (200 MHz, CDCl3) δ=2.4 (s, 1H), 2.2 (m, 2H), 1.1 (m, 14H), 0.8 (m, 2H).

Provenance & Evidence