Hydrochloric Acid → 5-Iodo-2,4-dimethoxybenzaldehyde

Participants

Reaction Steps

Ex-35B: To a solution of 2.4-dimethoxybenzaldehye (20.0 g, 120.4 mmol) in methanol (550 mL) was added iodine monochloride (23.5 g in 60 mL methanol) dropwise over 20 min at ambient temperature. The solution was allowed to stir at this temperature. HPLC showed about 94% conversion after 3 hours. The reaction mixture was then poured into a solution of HCl (0.5M, 600 mL). The precipitate was collected by filtration, washed with water, dried in vacuo (40° C.) to give crude product of 33.02 g. The crude product was further purified by recrystallization from THF/heptane (1:1) to give 5-iodo-2,4-dimethoxybenzaldehyde as an off-white solid (27.5 g, m.p 170–172° C.). The mother liquid was concentrated to dryness. The residual material was dissolved in EtOH (100 mL) and acetone (20 mL) followed by addition of water (20 mL) to give additional product (3.12 g, m.p. 169–171° C.). Overall isolated yield of this reaction was 87.5%. 1H NMR (CDCl3) δ 10.20 (s, 1H), 8.22 (s, 1H), 6.39 (s, 1H), 3.97 (s, 3H), 3.95 (s, 3H). HRMS Calcd. for C9H9IO3: 291.9596 (M+); Found: 291.9602. Anal. Calcd. for C8H9NO3S: C, 37.01; H, 3.11; 1, 43.33; Found: C, 37.12; H, 3.15; I, 43.33.

Provenance & Evidence