GENERAL METHOD: 2-chloro-4-iodopyridine (prepared above) was heated with sodium acetate (2.0 eq.) in 1.0 M acetic acid solution at 150°C for 72 hours in a sealed tube. After completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure. The residue was partitioned between ethyl acetate (3 mL/mmol) and cold water (3 mL/mmol). The aqueous layer was extracted with ethyl acetate (3 mL/mmol; 4 times). The combined organic layers were washed sequentially with saturated NaHCO3 solution (1 mL/mmol), brine, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by silica gel fast column chromatography to afford 4-iodo-2-pyridinone (1b/c/d), details of the specific compound are given below.
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