1-Trimethylsilyl-1-butyne

BuLi (2.6 M in hexane, 194 mL, 504 mmol) was addedto a stirred solution of but-1-yne (28.0 g, 518 mmol) in EtGeneral procedure: Alkenylsilane 2b was synthesized by a procedure similar to that for the synthesis of 2a as follows.A 3 L three-necked round bottom flask was charged with (trimethylsilyl)acetylene (116 g, 1.19 mol) and dry THF (400 mL). The solution was cooled to -78 °C. To this solution, butyllithium in hexane (2.5 M, 500 mL, 1.25 mol) was added dropwise over 2 hours. The resulting mixture was warmed to 0 °C for 10 minutes and then re-cooled to -78 °C. HMPA (234 g, 1.31 mol) was added, and the mixture was stirred at -78 °C for 30 minutes. To this solution, iodoethane (200 g, 1.28 mol) was added. The reaction mixture was allowed to warm to room temperature and stirred overnight. Upon completion, the reaction mixture was washed with water (4x600 mL) and then brine (2x500 mL). The organic layer was dried over anhydrous sodium sulfate and filtered. Hexane and THF were distilled off at 751 10 °C. But-1-yn-1-yltrimethylsilane was distilled between 125135 °C affording 91 g of a colorless liquid (6 1percent). 1H NMR (400 MHz, DMSO-d6) ö 2.20 (q, 2H), 1.05 (t, 3H), 0.11 (s, 9H); 13C NMR (100 MHz, CDCl3): ö 108.8, 83.3, 13.7, 13.4, 0.0.Intermediate 1But-l-yn- -yltrimethylsilane[00372] A 3 L three-necked round bottom flask was charged with (trimethylsilyl)acetylene (116 g, 1.19 mol) and dry THF (400 mL). The solution was cooled to -78 °C. To this solution, butyllithium in hexane (2.5 M, 500 mL, 1.25 mol) was added dropwise over 2 hours. The resulting mixture was warmed to 0 °C for 10 minutes and then re-cooled to -78 °C. HMPA (234 g, 1.31 mol) was added, and the mixture was stirred at -78°C for 30 minutes. To this solution, iodoethane (200 g, 1.28 mol) was added. The reaction mixture was allowed to warm to room temperature and stirred overnight. Upon completion, the reaction mixture was washed with water (4x600 mL) and then brine (2x500 mL). The organic layer was dried over sodium sulfate and filtered. Hexane and THF were distilled off at 75—110 °C. But-l-yn-l-yltrimethylsilane was distilled between 125 to 135 °C affording 91 g of a colorless liquid (61percent). 1H NMR (400 MHz, DMSO-de) δ 2.20 (q, 2H), 1.05 (t, 3H), 0.11 (s, 9H).Step-1.1: Synthesis of but-l-yn-l-yltrimethylsilane: To a stirred solution of (trimethylsilyl)acetylene (116 g, 1.19 mol) in dry THF (400 mL) was added rc-BuLi (2.5M in THF, 500 mL) at -78 °C over 2 h. The resulting mixture was warmed to 0 °C for 10 min. The reaction mixture was again cooled to -78 °C, HMPA (234 g, 1.13 mol) was added to the above mixture and stirred at -78 °C for 30 min. To the above reaction mixture iodoethane (200 g, 1.28 mol) was added and the resulting mixture was stirred at room temperature for 16 h. After completion of reaction, the reaction mixture was quenched with water, extracted with ethyl acetate (1000 mL). The organic layer was washed with brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure. The product but-l-yn-l-yltrimethylsilane was distilled between 125-135 °C to afford the desired product (91 g, 61 percent) as a colourless liquid.10204] To a stirred solution of (trimethylsilyl)acetylene (ii6 g, i.i9 mol) in dry THF (400 mE) was added n-l3uEi (2.5M in THF, 500 mE) at —78° C. over 2 h. The resulting mixture was warmed to 0° C. for iO mm. The reaction mixture was again cooled to —78° C., HMPA (234 g, i.i3 mol) was added to the above mixture and stirred at —78° C. for 30 mm. To the above reaction mixture iodoethane (200 g, i .28 mol) was added and the resulting mixture was stirred at room temperature for i 6 h. After completion of reaction, the reaction mixture was quenched with water, extracted with ethyl acetate (i000 mE). The organic layer was washed with brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure. The product but-i -yn-i - yltrimethylsilane was distilled between i25-i35° C. to afford the title compound of Ex. i Step-2 (9i g, 6ipercent) as acolourless liquid.The mixture of sodium ethylacetylide in xylene was admixed with 10 g of dimethylformamide and 108.5 g of trimethyl chlorosilane were added dropwise into the reaction mixture at 40° to 50° C. over a period of 1 hour.

Molecular Weight:126.27
Rotatable Bond Count:1
Exact Mass:126.086476981
Monoisotopic Mass:126.086476981
Heavy Atom Count:8
Complexity:116
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes