Trimethylsilylacetylene → HCID 68286487, compound

Participants

Reaction Steps

To a stirred solution of ethynyl trimethylsilane (39.1 mL, 277 mmol, 4 equiv) in THF (120 mL) at 0° C. was added ethylmagnesium bromide (3.16 M in Et2O; 87.6 mL, 277 mmol, 4 equiv). The reaction was allowed to warm to room temperature and stirred for 30 min. After 30 min at room temperature, CuBr (9.93 g, 69.2 mmol, 1 equiv) was added and the reaction was allowed to stir at room temperature for an additional 15 min prior to addition of 3,5-dimethoxybenzylbromide (16.0 g, 69.2 mmol, 1 equiv). The resulting mixture was heated to reflux overnight (20 h). The reaction was diluted with Et2O, cautiously quenched with brine, and extracted with Et2O (×2). The combined organic layers were washed with a saturated aqueous solution of NH4Cl, brine, dried (MgSO4), filtered, and concentrated under reduced pressure. The crude mixture was purified by chromatography on SiO2 (EtOAc/hexanes, 1:10) to give 17.2 g (100% yield) of 7 as a pale yellow oil: Rf 0.41 (EtOAc/hexanes, 1:20); IR (neat) 2956, 2898, 2175, 1754, 1596, 1459, 1428, 1204, 1156, 1122, 1101, 839 cm−1; 1H NMR (400 MHz, CDCl3) δ 6.53 (d, 2H, J=2.4 Hz), 6.34 (t, 1 H, J=2.4 Hz), 3.79 (s, 6 H), 3.60 (s, 2H), 0.19 (s, 9 H); 13C NMR (100 MHz, CDCl3) δ 160.8, 138.7, 105.9, 104.0, 98.7, 87.1, 55.3, 26.3, 0.1; HRMS (ESI+) m/z calcd for C14H21O2Si 249.1311, found 249.1287.

Provenance & Evidence