24Diiodoanisole

2,4‑Diiodoanisole is an iodinated aromatic ether with the molecular formula C7H7I2O and the SMILES notation Cc1cc(I)ccc1I. The compound appears as a white to pale yellow crystalline solid and has a melting point range of 145–147 °C. It exhibits limited solubility in water but dissolves readily in organic solvents such as dichloromethane, ethanol, and dimethylformamide.

The primary synthetic route to 2,4‑di­iodoanisole involves electrophilic iodination of anisole. A common method employs N‑iodosuccinimide (NIS) in the presence of a Lewis acid such as iron(III) chloride or aluminum trichloride. The reaction is typically conducted at low temperatures (0 °C to room temperature) to favor ortho‑and meta‑iodination over the para position, yielding the desired 2,4‑isomer in moderate to good selectivity. Alternatives include the use of iodine with oxidizing agents (e.g., oxone) under basic conditions. For larger scale synthesis, the Sandmeyer reaction can be adapted, although it requires additional steps to introduce the iodine atoms.

In the context of organic synthesis, 2,4‑di­iodoanisole serves as a versatile substrate for cross‑coupling reactions. Palladium‑catalyzed C–C and C–heteroatom bond formations, including Suzuki–Miyaura, Negishi, and Stille couplings, are frequently employed to append various functional groups onto the aromatic ring. Its dual iodine atoms allow for sequential or tandem reactions, enabling the construction of complex molecular architectures with high regiocontrol. The electron‑withdrawing effect of iodine also makes it an attractive precursor for the preparation of radio‑iodinated tracers used in diagnostic imaging and pharmacological studies.

Safety considerations for handling 2,4‑di­iodoanisole include the potential for skin and eye irritation. Its iodine content renders it a strong oxidizing agent, which can catalyze the decomposition of organic materials under heat or friction. Users should employ adequate personal protective equipment, work in a well‑ventilated area or fume hood, and avoid contact with open flames or strong reducing agents. Proper disposal should comply with local regulations governing halogenated organics.