反应详情

温度

70 °C

5-Bromo-pyridine-2-carboxylic acid tert-butylamide (Example 1, step 1) (280 mg, 0.92 mmol) was dissolved in THF (20 ml). 2-Chloro-4-trimethylsilanylethynyl-pyridine [CAS 499193-57-6] (222 mg, 1.06 mmol, 1.15 equiv.), Et3N (1.28 ml, 9.2 mmol, 10 equiv.), Bis-(triphenylphosphine)-palladium(II)dichloride (19 mg, 28 μmol, 0.03 equiv.) and copper(I)iodide (5 mg, 28 μmol, 0.03 equiv.) were added under nitrogen and the mixture was heated to 70° C. TBAF 1M in THF (970 μl, 0.97 mmol, 1.05 equiv.) was added dropwise over a period of 20 minutes at 70° C. The reaction mixture was stirred for 2 hours at 70° C. and evaporated in presence of Isolute® sorbent to dryness. The crude product was purified by flash chromatography with a 20 g silica gel column eluting with heptane:ethyl acetate 100:0→0:100. The desired 5-(2-chloro-pyridin-4-ylethynyl)-pyridine-2-carboxylic acid tert-butylamide (210 mg, 73% yield) was obtained as a white solid, MS: m/e=314.4/316.4 (M+H+).

1. customevaporated in presence of Isolute® sorbent to dryness
2. customThe crude product was purified by flash chromatography with a 20 g silica gel column
3. washeluting with heptane:ethyl acetate 100:0→0:100