Iodine chloride → 2-Chloro-5-iodopyridin-4-amine

Iodine monochloride (0.758 g, 4.67 mmol) was added to a solution of 2-chloro-4-amino pyridine (0.500 g, 3.89 mmol) and potassium acetate (0.763 g, 7.78 mmol) in acetic acid (30 mL). The reaction mixture was heated under reflux for 4 hr. The solvent was removed in vacuo and the residue was partitioned between aqueous sodium hydrogenocarbonate (50 mL) and ethyl acetate (50 mL). The organic phase was dried (MgSO4) and the solvent was removed in vacuo. The crude product was purified by flash silica chromatography, eluting with ethyl acetate and hexane (1/9), to give the title compound as a pink solid (0.394 g, 40%).