Trimethylsilylacetylene → Methyl 3-[(dipropylamino)carbonyl]-5-[(trimethylsilyl)ethynyl]benzoate

Participants

Reaction Steps

A solution of methyl 3-bromo-5-[(dipropylamino)carbonyl]benzoate (25) (200 mg, 0.58 mmol), PdCl2(Ph3P)2 (16 mg, 0.03 mol %) and CuI (6 mg, 0.05 mol %) in triethylamine (1.2 mL) was heated to reflux. (Trimethylsilyl)acetylene (100 μL, 0.7 mmol) was added, and the bright yellow solution quickly turned orange then went brown within a minute. The reaction mixture was stirred for 3 h, cooled to room temperature, diluted with H2O (20 mL), and extracted with CHCl3 (3×15 mL). The combined organics were washed with saturated NaCl (20 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure to give methyl 3-[(dipropylamino)carbonyl]-5-[(trimethylsilyl)ethynyl]benzoate 26 (185.5 mg): 1H NMR (300 MHz, CDCl3): δ 7.95 (s, 1H), 7.75 (s, 1H), 7.43 (s, 1H), 3.74 (s, 3H), 3.25 (br s, 2H), 2.95 (br s, 2H), 1.49 (br s, 2H), 1.34 (br s, 2H), 0.79 (br s, 3H), 0.56 (br s, 3H), 0.06 (s, 9H).

Provenance & Evidence