1-Butanesulfonyl chloride stands out as a sulfonyl chloride compound with the molecular formula C4H9SO2Cl. In practical terms, this chemical works as an industrial reagent and often appears as a solid that ranges from white to off-white flakes, powder, or sometimes as crystalline grains. Handling the raw material, you notice an acrid, slightly biting odor, typical of many sulfonyl chlorides. Its density typically hovers around 1.2 g/cm3, though temperature and crystal packing influence the measurable value. The compound meets HS Code 29041090, falling within a category of organic sulfonic acids and their corresponding halides and derivatives.
Taking a close look at the atomic structure, the 1-butane chain attaches directly to a sulfonyl chloride group (–SO2Cl), which determines much of its chemical reactivity. This structural choice gives it its characteristic reactivity as a sulfonating and chlorinating agent. In most labs and production environments, the powder or flakes dissolve in chlorinated solvents, ether, or acetone, but water rapidly hydrolyzes the material—producing corrosive, pungent gases. The boiling point sits high, so the compound stays stable until strong heating, after which it decomposes before full vaporization. This property helps explain why it rarely appears in a liquid state within standard laboratory conditions, as room temperature favors the solid form—usually crystals or powder.
On the bench or in a storage drum, 1-butanesulfonyl chloride usually presents as a solid with crystalline or flaky texture, suitable for careful weighing and transfer. Rarely offered as pearls due to its tendency to clump, bulk stocks can be kept in sealed containers because the material absorbs moisture, triggering release of hydrochloric acid gas and butanesulfonic acid. Solubility remains limited in cold water, but organic media allow full dispersion, making solution-based applications more manageable inside chemical synthesis work. Density differences can be subtle among different crystal forms, but users notice quick melting at elevated temperatures, with a melting point around 35–40°C, which leads to a flowing oil if left on a warm plate.
With a clear C4H9SO2Cl composition, the compound has a molecular weight of about 172.63 g/mol. In chemical catalogs and procurement sheets, such specifications matter for scale calculations and hazard classification. The structure, where the sulfonyl chloride group anchors to a linear four-carbon butane backbone, supports selective reactions in organic synthesis, particularly where introduction of the sulfonyl group is required without interference from aromatic characters. Purity standards usually exceed 98% for laboratory usage, but commercial grades might show minor impurities that can affect end-product qualities in industries like pharmaceuticals or specialty surfactants. Appearance descriptions such as solid, flakes, powder, or crystals typically match the actual material found in shipping containers upon delivery.
In my own experience handling sulfonyl chlorides, proper gloves, goggles, and fume hoods are mandatory. This compound is hazardous—its fumes corrode metals, damage respiratory tract linings, and cause chemical burns on skin contact. Direct inhalation or prolonged exposure can trigger coughing fits or more severe pulmonary irritation, so personal protective equipment cannot be an afterthought. In rare cases of accidental spills, copious water neutralization generates hazardous runoff that calls for proper containment. Storage recommendations always include airtight seals, cool dry conditions, and separation from moisture or incompatible substances like amines, alcohols, and bases. Labeling aligns with global harmonization regulations, considering both its corrosive and harmful profile, reflecting the material’s risk in every phase—manufacture, packaging, delivery, and use.
1-Butanesulfonyl chloride plays a key part in the synthesis of specialty chemicals, intermediates, and even some active pharmaceutical ingredients. Companies rely on its sulfonating power to attach butanesulfonyl groups to a range of organic frameworks. This role highlights why access to consistent, high-purity raw materials shapes the overall reliability and safety of the resulting products. In other settings, it’s chosen over aromatic sulfonyl chlorides specifically when an aliphatic (non-aromatic) sulfonyl moiety is needed, giving chemists options for tailored molecular design. The importance of robust supplier relationships and quality certificates goes beyond simple regulatory compliance—production outcomes rely directly on how well quality requirements for this raw material are met in both small-scale laboratory and industrial settings.
Seeing the injuries and near-misses in industry encourages more than basic caution. Routine safety audits, emergency eye-wash stations, and staff trainings cannot be skipped. Manufacturers seek to reduce harmful byproducts during large-scale use, employing scrubbers or closed systems to trap acid gases. Waste streams, particularly acidic aqueous solutions, require neutralization prior to disposal, and oversight remains strict due to both environmental and workplace health regulations. Promoting safer alternatives only works for certain applications; this material’s specific chemical behavior rarely finds true substitutes in advanced synthesis, so tighter procedural controls and improved engineering solutions drive risk reduction in practice.
In terms of shipments and purchases, 1-butanesulfonyl chloride most often reaches the user as a bulk crystalline solid or finely divided powder, packed in drums lined with chemically resistant materials. The choice of form impacts not only safety but also the ease of measurement and mixing in downstream processes. Facilities sometimes convert it to solution in organic solvents for safer dosing and smoother process control. The distinctive molecular structure dictates reactivity in both lab and industrial environments, and anyone considering switching to or adopting this material needs to weigh personal safety, environmental protocols, and reaction outcome goals. Consistent, clean supply supports both research innovation and predictable, large-scale outputs in chemical manufacturing.
