Methyl 4-iodobutyrate comes as a specialized compound in the realm of organic chemistry. As a derivative of butyric acid, this substance features an iodine atom attached to the fourth carbon and a methyl ester group. I have come across it in various forms, typically as a colorless to pale yellow liquid. With a molecular formula of C5H9IO2 and a molar mass of about 244.03 g/mol, it presents as an important building block in synthesis, especially among research labs and specialty chemical providers.
A look at its structure tells much about how this material behaves. The compound contains a four-carbon chain with the iodine atom bonded to the terminal carbon, and an ester group at the first carbon. Its density typically hovers near 1.72 g/cm³ at room temperature, though anyone handling the material should expect slight variations based on concentration and purity. Boiling point measurements tend to fall around 80-85°C at 20 mm Hg, which signals a moderate volatility. In my own handling, I have noted its distinct, slightly sharp odor and its slick, oily texture—common in many organic esters and iodine-based intermediates. Methyl 4-iodobutyrate does not dissolve well in water; it prefers organic solvents like dichloromethane, chloroform, and ether. This property often comes in handy during purification steps or solvent extraction processes.
This compound often draws attention due to the presence of both an ester, which reacts under basic or acidic hydrolysis, and an iodide, which serves as a prime target for nucleophilic substitutions. From experience in the lab, I can say that its reactivity enables creative synthetic options for researchers looking to develop more advanced molecules, especially those targeting pharmaceutical or agrochemical industries. Chemicals with an iodine group at the terminal carbon generally fit well in coupling reactions, so chemists like to use this compound as a raw material or as a precursor for further molecular modifications. Some protocols take advantage of its ability to undergo nucleophilic substitution rather easily, yielding products that would be much trickier with other halides.
Users typically find methyl 4-iodobutyrate as a liquid, though under cold conditions or with impurities, it may show as crystals. Larger commercial suppliers may offer it in small drums or glass bottles, protected from light and moisture. When poured, it flows smoothly and can form clear droplets or, if highly pure, refract light in a way that gives off a slight shimmer. In terms of physical handling, the substance runs as a viscous oil, rather than as a powder, flake, solid, pearl, or flaked material. Its appearance may change under suboptimal storage—exposure to humidity or extreme cold can prompt slight crystallization, though such cases remain rare in professional storage conditions.
Goods containing iodine in organic chemicals often fall under the HS Code 2915.90, a category that covers carboxylic acid derivatives. Based on publicly available customs data, import and export paperwork requires clear specification of this code. Standard technical sheets specify purity (commonly ≥97%), limiting moisture content, and clarifying presence of any stabilizers or inhibitors. For buyers working with Methyl 4-iodobutyrate, a certificate of analysis offers reliable assurance that each batch meets expectations in structure, density, boiling point, and iodine content.
A material like methyl 4-iodobutyrate enters the conversation of safe practice thanks to its status as both a hazardous and potentially harmful chemical. My labs’ safety training stressed the need for gloves, goggles, and use of fume hoods—this compound can harm skin and eyes on contact, and its vapors cause irritation. Inhalation of vapors or accidental skin exposure often results in rapid, unpleasant symptoms, such as irritation or rash. Proper storage calls for tightly sealed containers away from sources of ignition or water. Fire safety officers always warn against using this substance near open flames; most MSDS sheets classify it as both flammable and as a source of hazardous combustion products if heated beyond its decomposition point. If a spill occurs, quick containment and disposal according to regulated procedures limit the risk to personnel and the facility.
Methyl 4-iodobutyrate stands out as an intermediate for researchers and industrial chemists who need a functional, reactive molecule for building complex structures. Several pharmaceutical pipelines use iodoalkyl esters as starting materials. I have witnessed the value of this compound as a springboard for making new molecules, especially in the early stages of drug design. Given the importance of iodine in radiolabeling and therapeutic agents, this compound’s unique structure offers practical opportunities for innovation. Reliable access to a well-made material often makes the difference between successful synthesis and wasted resources.
