2-Bromo-5-fluoropyridine → 2-(4-(5-Fluoropyridin-2-yl)but-3-ynyl)-imidazo[1,2-a]pyridine

Participants

Reaction Steps

In a dry reaction tube containing in suspension copper iodide (6.5 mg, 0.03 mmol) and triethylamine (2.3 mL), were added 2-bromo-5-fluoropyridine (120 mg, 0.68 mmol) and Pd(PPh3)2Cl2 (39 mg, 0.03 mmol) under N2. A yellow suspension was obtained after 5 min of stirring at room temperature. A solution of 2-(but-3-ynyl)-imidazo[1,2-a]pyridine (120 mg, 0.68 mmol) in triethylamine (0.5 mL) was then added under N2. Immediately the color of the reaction turns to black. The mixture was stirred at room temperature for 30 min and heated at 80° C. overnight. The reaction mixture was concentrated and the crude product was purified by Flash chromatography (prepacked 25 g silicagel column, DCM/MeOH from 100/0 to 97/3 as eluent) to afford 15 mg of 2-(4-(5-fluoropyridin-2-yl)but-3-ynyl)-imidazo[1,2-a]pyridine (Yield: 8%) as a brown semi-solid.

Provenance & Evidence