4-Bromobutyryl Chloride lands in the realm of organic synthesis as a reactive and hazardous compound. Chemical manufacturers and researchers often recognize it by the formula C4H6BrClO and its structure: a four-carbon butyryl chain terminated at one end by a bromine atom and at the other by an acyl chloride group. Practically, this layout gives the molecule its biting reactivity and value in the lab. With a molecular weight of 185.45 g/mol, it integrates into organic intermediates for active pharmaceutical ingredients, agrochemical raw materials, and advanced materials. Raw forms can show up as a colorless to pale yellow liquid, sometimes with irritating fumes escaping from unsealed containers.
People handling 4-Bromobutyryl Chloride see its physical properties in real time. The compound stands out for a dense liquid state at room temperature, a robust, acrid odor, and the ability to fume in moist air. Density tips toward 1.517 g/cm³ around 20°C. Anyone working in a lab gets a quick education in how moisture triggers hydrolysis, releasing hydrochloric acid and 4-bromobutyric acid. This chemical isn’t something that lingers on the shelf for long due to its strong tendency to react. The flammability risk lingers low, but corrosivity sits high on the hazard list because the acyl chloride reacts with skin and tissues, not just water. Chemically, the molecule offers an alpha-haloacyl skeleton, so it functions as both an alkylating agent and a source of butyryl groups in synthetic chemistry. The crystalline solid form rarely appears in standard environments; most users and suppliers encounter it as a viscous liquid in sealed glass or HDPE containers, sometimes under nitrogen protection.
Production teams depend on 4-Bromobutyryl Chloride for constructing specialized building blocks. One striking application: as a reagent for introducing the butyryl group in pharmaceuticals and specialty chemicals. Chemists use this chemical to modify peptides and proteins, often in research settings focused on targeted biological activity. The raw material interacts with alcohols, amines, and other nucleophiles, delivering a range of derivatives that feed into drug discovery, fragrance, and agricultural chemistry pipelines. Researchers often cite its role in making protected amino acids and novel brominated intermediates. This compound’s position in the supply chain stretches from scale-up at multi-ton sites to benchtop synthesis, with shelf-life limitations pushing for just-in-time delivery. Besides research, process chemists sometimes develop custom protocols for intermediates that can handle the harsh conditions set by this molecule’s corrosive behavior.
Anyone pulling a bottle of 4-Bromobutyryl Chloride from the chemical shelf ought to know the rules—gloves, goggles, lab coat, access to a fume hood, and well-labeled containers. Even a small spill generates hydrochloric acid fumes in the presence of water vapor, stinging the nose and eyes. Direct skin or eye contact rapidly burns and corrodes tissues, so users lean on calcium chloride tubs and dedicated acid trash. Labs keep calcium gluconate gel on hand in case of hydrofluoric acid releases, which is not directly related but says plenty about the class of hazards. Storage means a cool, dry, well-ventilated room, far away from amines, alcohols, and bases—since accidental release leads straight to a lab incident. Site managers favor HDPE bottles or amber glass, never metal, because corrosion leads to early failure. Local and international standards, including the UN hazard code 3265 (Corrosive Liquid, Acidic, Organic, N.O.S.) and the Harmonized System (HS) Code 2915900090, guide shipping and import/export paperwork, keeping logistics people on their toes.
Suppliers sort lots with tight specs, both for purity and physical appearance. Buyers request content above 98%, with water and acid impurities tested by titration and gas chromatography. Each shipment includes certificates of analysis referencing methods such as NMR, IR, and GC-MS fingerprints. Manufacturers pay close attention to how the liquid handles temperature swings and storage. Specifically, customers tend to avoid flaky, solidified, or crystallized material, as these point to mishandling and a risk of side reactions. Color counts—deep yellow or brownish material flags an impurity load that can spoil downstream reactions. Because 4-Bromobutyryl Chloride stays active, packaging includes inert atmospheres and sealed liners. Lab technicians and production chemists check samples before use—not only with analytical data but with experience, spotting off odors or visible changes that suggest hydrolysis or contamination.
Used in even moderate amounts, this chemical earns its hazardous rating. Regional and global chemical control authorities including OSHA, EPA, REACH, and the Chinese MEE regulate how companies handle, transport, and dispose of it. Large-scale users manage permits covering air emissions, effluent limits, and hazardous waste manifesting. Routine spills need instant neutralization—often with sodium bicarbonate or a specialized neutralizer—before cleanup. Community safety obligations mean keeping storage below recommended volumes, especially in educational and urban settings. End-of-life material requires treatment as a halogenated organic waste, not as normal organic trash, keeping chlorinated breakdown products out of water and soil.
Chemists with years in the lab know 4-Bromobutyryl Chloride demands respect but gives back efficiency and flexibility across projects. The sharp smell and fuming edge linger long after a batch wraps up, a memory that sticks as well as lessons about the power and challenge of handling advanced reagents. Teams plan every transfer, every dilution, with clear protocols and robust personal protective equipment. Mistakes leave marks—chemical burns heal, but the reminder to check every label before breaking the seal sticks with professionals through decades of work. With increased regulatory scrutiny and supply chain checks, buyers now expect tracked, traceable deliveries and end-to-end safety data. The chemical world keeps evolving, but 4-Bromobutyryl Chloride remains a key link—the kind that reminds you that behind every bottle stands a network of engineers, scientists, and safety managers looking out for end users and the environment.
