Preparation of 3-Pyridylzinc Bromide

An oven-dried 100ml round-bottomed flask was charged with 3.3 g of active zinc (50 mmol) in 30 ml of THF and 0.2 g of lithium chloride (20 mol%) under the positive pressure of argon gas. 3.9 g of 3-bromopyridine (25 mmol) was added into the solution of active zinc at rt. The resulting mixture was then 

Stirred at refluxing temperature for 2 h, cooled down to rt, and allowed to settle overnight. The supernatant was used for the subsequent coupling reactions. 

---