Diisopropyl Ether → 4-Trimethylsilanylethynyl-thiazole-2-carboxylic acid-(6-acetyl-3-methoxy-2-methyl-phenyl)-amide

Participants

Reaction Conditions

Reaction Steps

To a suspension of compound 207b (10.12 g, 1 eq.) in diisopropylamine (40 mL) were added ethynyltrimethylsilane (5.7 mL, 1.5 eq.), triphenylphosphine (0.283 g, 0.04 eq.), copper iodide (0.206 g, 0.04 eq.), and PdCl2(PPh3)2 (0.38 g, 0.02 eq.). The mixture was stirred under nitrogen and heated to 80° C. (external temperature). After 10 min, the solvent was refluxed, and the mixture solidified and turned brown grey. DIPA (20 mL) was added to solubilize the reaction mixture. After 2.5 hrs, the reaction was complete and the mixture cooled down to room temperature. Diisopropyl ether (20 mL) was added. A grey solid was recovered by filtration, dissolved in dichloromethane, and washed with water. The organic layer was dried over Na2SO4, filtered, and concentrated to give black solid. The residue was purified by chromatography on silica gel (dichloromethane) to give compound 208b as a beige solid in 84% yield. 1H NMR (CDCl3, 400 MHz) δ (ppm) 0.29 (s, 9H), 2.13 (s, 3H), 2.58 (s, 3H), 3.93 (s, 3H), 6.81 (d, J=8.78 Hz, 1H), 7.69 (s, 1H), 7.76 (d, J=8.78 Hz, 1H), 11.05 (s, 1H).

Provenance & Evidence