General procedure for the synthesis of 2-fluoro-4-iodo-5-(methoxymethoxy)pyridine from 2-fluoro-5-(methoxymethoxy)pyridine: 2-fluoro-5-(methoxymethoxy)pyridine (4.1 g, 26.1 mmol) was dissolved in THF (60 mL) and cooled to -75 °C. Tert-butyl lithium (1.7 M in pentane, 30.4 mL, 51.7 mmol) was slowly added over 30 min. After addition, stirring was continued at -75 °C for 30 min. Subsequently, iodine (9.8 g, 38.6 mmol, dissolved in 60 mL THF) was added. After addition, stirring was continued for 1 hour. The temperature was slowly increased to room temperature and stirring was continued for 1 hour. Upon completion of the reaction, the reaction was quenched with water. The reaction mixture was extracted with ethyl acetate (3 × 60 mL). The organic layers were combined and washed with saturated aqueous sodium chloride. The organic layer was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give a brown solid. The brown solid was ground with hexane and filtered to give 2-fluoro-4-iodo-5-(methoxymethoxy)pyridine (3.9 g, 53% yield) as a brown solid.1H NMR (400 MHz, CDCl3) δ 3.53 (s, 3H), 5.23 (s, 2H), 7.39 (d, J = 4.0 Hz, 1H), 7.96 (d, J = 1.6 Hz, 1H).
