Trimethylsilylacetylene → Methyl 3-[(dipropylamino)carbonyl]-5-ethynylbenzoate

Participants

Reaction Steps

A mixture of methyl 3-bromo-5-[(dipropylamino)carbonyl]benzoate (XXI, 200 mg, 0.58 mmol), PdCl2(Ph3P)2 (16 mg, 0.03 mol %) and copper (I) iodide (6 mg, 0.05 mol %) in triethylamine (1.2 mL) is heated to reflux. (Trimethylsilyl) acetylene (100 microliter, 0.7 mmol) is added, and the mixture stirred for 3 hours, cooled to 20–25 degrees, diluted with water (20 mL), and extracted with chloroform (3×15 mL). The combined organic extracts are washed with saline (20 mL), dried over sodium sulfate and concentrated under reduced pressure to give methyl 3-[(dipropylamino)carbonyl]-5-ethynylbenzoate (XXXII, 185.5 mg), NMR (300 MHz, CDCl3): δ 7.95, 7.75, 7.43, 3.74, 3.25, 2.95, 1.49, 1.34, 0.79, 0.56 and 0.06.

Provenance & Evidence