Step A. Synthesis of 2-iodo-1-methoxy-4-nitrobenzene
2-Methoxy-5-nitroaniline (10.0 g, 0.060 mol) was suspended in water (150 mL) and concentrated sulfuric acid (12 mL, 0.22 mol) was added slowly. The temperature of the reaction mixture was maintained below 5 °C under cooling in an ice-salt bath, and a solution of sodium nitrite (4.8 g, 0.070 mol) in water (40 mL) was added dropwise. Subsequently, potassium iodide (16.8 g, 0.101 mol) was added and the mixture was heated to 90 °C and kept for 1 hour. Upon completion of the reaction, it was cooled to 0 °C and deep red crystals were precipitated, which were filtered, washed with water and dried. Purification by silica gel column chromatography (eluent: ethyl acetate/hexane) afforded the target compound 2-iodo-1-methoxy-4-nitrobenzene (13.6 g, 75% yield).
1H NMR (300 MHz, DMSO-d6): δ 8.57 (s, 1H), 8.28 (d, 1H), 7.19 (d, 1H), 3.98 (s, 3H).
LCMS (M + H)+: m/z = 280.1 (C7H7INO3).