Hydrogen iodide

Hydrogen iodide (CAS 10034-85-2), commercially supplied as hydroiodic acid, is an inorganic acid used primarily as a reducing agent and iodine source in chemical synthesis. In aqueous solution, it delivers both strong acid activity and iodide ion availability. This makes it a valued reagent across pharmaceutical manufacturing and specialty chemistry. In pharmaceutical synthesis, it serves as a key reagent for dealkylation reactions, particularly in the production of active pharmaceutical ingredients.

It is frequently used where methyl ether cleavage is required for complex molecules. Food-grade hydroiodic acid is used in limited acidulant and iodine-fortification applications where precise iodide delivery is needed for specific formulations. In biotechnology and life sciences, it functions as a reagent in nucleotide chemistry and iodination protocols for labeling and analytical workflows. Industrial pH adjustment processes also draw on its strong acid character.

This is particularly useful where iodide co-introduction is acceptable or required for the final product. The chemical is supplied as an aqueous solution, with 47% and 57% w/w concentrations being the most commercially standard. Reagent-grade and ACS-grade specifications are typical for laboratory and synthesis supply. Pharmaceutical-grade material is also available to meet API manufacturing requirements and rigorous quality control protocols.

Stabilized and unstabilized variants exist for different industrial needs. Stabilized grades include a hypophosphorous acid additive to prevent oxidation and maintain product clarity during long-term storage and transport.