2-Chloro-5-iodobenzoic acid belongs to the family of halogenated benzoic acids, known for their distinctive roles in organic synthesis, research, and pharmaceutical intermediate production. With its chemical backbone anchored by both a chlorine and an iodine atom positioned on the benzene ring, 2-Chloro-5-iodobenzoic acid stands out within specialty chemicals. The presence of these halogens changes its reactivity and influences the path it takes in various chemical transformations. Amateur chemists might notice its sharp odor and subtle color changes, as it often trends from off-white to light tan in appearance. Having handled related benzoic acids in the lab, the substantial effect of each substitution becomes easy to recognize in their reactivity and solubility.
People use 2-Chloro-5-iodobenzoic acid as a raw material for the preparation of more complex organic compounds, making it valuable in designing targeted pharmaceuticals and advanced agrochemicals. Research chemists put it to work in Suzuki and Sonogashira coupling reactions thanks to the combined halogen sites, which support diverse substitution strategies. It often serves as a building block for molecules that demand both reactivity and stability in their core structure. In industry, companies draw from its well-documented structure to develop custom synthesis routes for niche products. It also turns up in the learning kits for advanced chemistry students exploring cross-coupling reactions, its unique make-up providing a clear example of how halogen substitution impacts synthetic planning.
The molecular formula for 2-Chloro-5-iodobenzoic acid is C7H4ClIO2, highlighting the interplay of carbon, hydrogen, chlorine, iodine, and oxygen. Structurally, this compound features a benzene ring where chlorine holds the 2-position, iodine occupies the 5-position, and the carboxylic acid group fixes to the 1-position. That arrangement alters both the chemical outlook and physical feel of the raw material. Picture a solid form, crystalline by nature, sometimes appearing as dull white or light-colored flakes. This visual evidence often signals purity, but contaminants or degradation can darken the color. The molecular weight, resting around 282.47 g/mol, gives clear direction to handling and shipping practices, especially in projects requiring precise dosing or molar calculations.
This material lands on laboratory shelves as a solid substance—never found liquid under standard conditions—so anyone working with it should expect powder, flakes, or crystalline aggregates. Its melting point usually hovers between 205°C to 209°C, placing it alongside other stable acidic solids. Water solubility might disappoint those seeking easy dissolving: it resists most common solvents except for some polar organics, so chemists reach for dimethyl sulfoxide (DMSO), dimethylformamide (DMF), or acetonitrile when they aim to get it into solution. Density runs close to 2.14 g/cm³, making it heavier than many common organics, something easy to feel when scooping the solid powder with a spatula—the heft offers a reminder that the iodine atom does much of the heavy lifting.
Pure 2-Chloro-5-iodobenzoic acid normally appears as solid powder, crystalline flakes, or small pearls depending on the granulation process during manufacturing. It forms clean, brittle crystals under the right cooling conditions, though it can become slightly sticky if exposed to air moisture for long periods. The surface feel tells you a lot—I've seen well-stored bottles containing powder as loose as flour, while others, forgotten in a humid lab, begin lumping. Users rarely come across it as a solution, as in-solution forms must be freshly prepared to ensure accurate concentrations for experimental consistency. Stock solutions call for known solvents and careful measurement, since oversaturation leads to precipitate forming at the bottom of the bottle, frustrating ambitious synthetic plans.
The chemical nature of 2-Chloro-5-iodobenzoic acid comes straight from its halogen content and carboxylic acid group. Chlorine and iodine both pull electron density, shifting acidic strength compared to regular benzoic acid and increasing its value as a substrate for metal-catalyzed couplings. Because of these functional groups, the substance absorbs UV light in well-defined spectrums, making it easy to track using analytical techniques in organic chemistry. In method development for new compounds, the dual halogen pattern provides not only reactivity but also a traceable fingerprint that stands out in chromatograms and spectra.
Like most halogenated aromatics, 2-Chloro-5-iodobenzoic acid calls for careful handling. Direct inhalation, ingestion, or prolonged skin contact leads to irritation—the distinctive chemical taste and odor serve as reminders to practice safe lab work. Working with this compound in a well-ventilated hood, while wearing gloves and goggles, protects workers from potential harm. Safety Data Sheets (SDS) list it as harmful on accidental exposure, especially if used outside proper chemical management protocols. Its persistence in the environment raises a flag around proper waste disposal, and so any unused or spent chemical gets disposed according to hazardous waste regulations. I remember a close call early in my career—one careless transfer led to minor skin irritation, but it stuck with me as a lesson on the importance of respecting even “routine” compounds.
2-Chloro-5-iodobenzoic acid finds its classification in international trade under HS Code 291639, which designates aromatic carboxylic acids and their derivatives. Shipping regulations look for clean, dry, clearly labeled containers to keep cross-contamination at bay. Most reputable suppliers ship this raw material in double-sealed bottles or drums with full documentation referenced back to the HS Code for both compliance and customs. Keeping track of material by correct code streamlines global sourcing and ensures legal as well as ethical chemical movement across borders.
The place of 2-Chloro-5-iodobenzoic acid in chemical synthesis, pharmaceutical development, and advanced research continues to grow as new reactions and derivatives demand flexible, robust starting materials. Advanced knowledge and respect for its physical and chemical properties shorten the path from initial experiments to successful full-scale production. When handling this substance, the experience that seasoned chemists and new learners collect remains just as valuable as the printed literature. As new methods and safety guidelines emerge, the balance between innovation and responsible management shapes both the product’s legacy and the safety of all involved.
