Sodium Iodide → 2-Ethyl-3-iodopyrazolo[1,5-a]pyridine

Participants

Reaction Steps

To a mixture of 2-ethylpyrazolo[1,5-a]pyridine (360 g, 2.46 mol), ethyl acetate (3600 mL), water (1800 mL) and sodium iodide (480 g, 3.20 mol, 1.3 equivalent) was added N-chlorosuccinimide (411 g, 3.08 mol) over a period of 30 minutes under cooling in an ice water bath, then, the reaction mixture was stirred at room temperature for 2 hours and 20 minutes. To the reaction mixture was added water and ethyl acetate, and the resulting mixture was extracted with ethyl acetate. The separated organic layer was washed twice with a 10% sodium thiosulfate aqueous solution, and concentrated under reduced pressure. To the resulting residue was added hexane, the residue was dissolved with heating. The hexane solution was filtrated to remove an insoluble substance. The hexane solution was washed with water, and concentrated under reduced pressure. Then, the resulting residue was dissolved in ethyl acetate, and the solvent was distilled off under reduced pressure, to obtain 663 g of a title compound (yield: 98.9%).

Provenance & Evidence