Iodobenzene, a fundamental organoiodine compound with the CAS number 591-50-4, is a cornerstone in organic synthesis due to its unique reactivity and versatility. As a derivative of benzene where one hydrogen atom is replaced by an iodine atom, its chemical formula is C6H5I. This compound is a colorless liquid that can appear yellowish with age, especially when exposed to light, highlighting the need for proper storage. For professionals in chemistry and related industries, understanding its synthesis and applications is crucial when considering its procurement.

Synthesis of Iodobenzene

The primary method for synthesizing Iodobenzene in the laboratory and on an industrial scale involves the diazotization of aniline followed by reaction with potassium iodide. This process begins with treating aniline with nitrous acid (generated in situ from sodium nitrite and a strong acid like hydrochloric acid) at low temperatures to form a diazonium salt. Subsequently, the diazonium salt is reacted with potassium iodide, which displaces the diazonium group and introduces the iodine atom, releasing nitrogen gas. This method is efficient and allows for the production of high-purity Iodobenzene, often exceeding 99.0%.

Key Chemical Properties and Reactivity

Iodobenzene exhibits a melting point of approximately -29 °C and a boiling point of around 188 °C. Its density is about 1.823 g/mL at 25 °C. The most significant chemical property driving its utility is the relatively weak carbon-iodine bond. This makes Iodobenzene more reactive than its chloro- or bromo- counterparts in nucleophilic substitution and coupling reactions. It readily reacts with magnesium to form phenylmagnesium iodide, a Grignard reagent vital for carbon-carbon bond formation. Furthermore, it serves as an excellent substrate for various transition-metal-catalyzed cross-coupling reactions, including:

  • Sonogashira Coupling: Reaction with terminal alkynes to form diarylalkynes.
  • Heck Reaction: Coupling with alkenes.
  • Suzuki-Miyaura Coupling: Reaction with organoboron compounds to form biaryls.

Applications of Iodobenzene

The versatility of Iodobenzene translates into a broad spectrum of applications:

  • Pharmaceutical Intermediates: Crucial for synthesizing complex drug molecules and active pharmaceutical ingredients (APIs).
  • Agrochemical Intermediates: Used in the production of pesticides, herbicides, and other crop protection agents.
  • Dye Intermediates: Contributes to the synthesis of various industrial dyes and pigments.
  • Fine Chemical Synthesis: A building block for numerous specialty chemicals, inhibitors, and antioxidants.
  • Organometallic Chemistry: As a precursor for Grignard reagents and other organometallic species.

Sourcing Iodobenzene

For companies looking to buy Iodobenzene, particularly in bulk, partnering with established China manufacturers and suppliers is often the most strategic approach. These suppliers can provide high-purity Iodobenzene at competitive Iodobenzene prices, backed by robust quality control and reliable logistics. When evaluating potential partners, consider their adherence to purity standards (e.g., ≥99.0%), their production capacity, and their responsiveness to inquiries. Ensuring a stable supply of this essential intermediate is critical for uninterrupted research and production.