5-Chlorothiophene-2-sulfonamide stands out in the crowded world of laboratory chemicals for a reason—it brings a combination of unique chemical structure and valuable reactivity. As the name suggests, the compound stems from a thiophene ring decked with a chlorine atom at the 5-position and a sulfonamide group at the 2-position. This blend gives it physical and chemical properties you don’t see in more basic sulfonamides or chlorinated aromatics.
The backbone of 5-chlorothiophene-2-sulfonamide owes its properties to its molecular formula, C4H4ClNO2S2, and a molecular weight sitting at approximately 213.73 g/mol. The chemical structure features a five-membered thiophene ring, one chlorine substituent replacing a hydrogen atom at the fifth site, along with a sulfonamide group branching off the second carbon. These elements turn a modest sulfur-containing heterocycle into a compound that’s more than a simple building block—it opens doors for synthesis in pharmaceuticals and chemical research labs alike.
In its pure form, 5-chlorothiophene-2-sulfonamide appears as a solid. Its appearance ranges from off-white to slightly pale yellow crystalline flakes, sometimes surfacing as a finer powder or even solidified beads, depending on the method of production or purification. Density clocks in at roughly 1.6-1.7 g/cm³, typical for sulfonamide derivatives tethered to aromatic rings. You won’t find it melting until reaching a temperature well above 160°C. The compound generally has low solubility in water but responds well to polar organic solvents like dimethyl sulfoxide and acetone, revealing its usefulness for solution-based chemical development, intermediate production, or chromatographic work.
Chemical handling always deserves respect—5-chlorothiophene-2-sulfonamide is no exception. The material may not wield the same hazards as strong acids or volatile solvents, but it can pose risks typical for organosulfur sulfonamides. Skin or eye contact causes irritation, and inhalation of dust is best avoided in a lab setting. In my lab years, I learned early not to take shortcuts with intrinsic hazards—even for a compound with a relatively modest SDS sheet. Protective gloves, goggles, and proper local ventilation do more than check compliance boxes. They ensure you’re not adding a health-related variable into an already complicated synthesis. A responsible lab stores this material away from oxidizing agents and bases, minimizing the risk of hazardous reactions.
Commercial suppliers offer 5-chlorothiophene-2-sulfonamide in a number of forms. Standard practice sees it supplied as a powder or crystalline solid, sometimes ground finer for specific synthetic needs. Bulk shipments show up in larger flakes or chips, easy to weigh out and dissolve as needed. Liquid or solution forms rarely circulate unless pre-dissolved for precise dosing, since the parent compound shines brightest as a solid intermediate ready for transformation. The form you select always depends on downstream use, but solubility data plays into formulation decisions just as much as density or crystalline habit.
Any buyer—chemist or not—needs accurate specifications for 5-chlorothiophene-2-sulfonamide: purity percentages, moisture content, melting point, and trace impurity levels can affect reactions downstream. Purity often lands above 97% for research-grade batches. HS Code—used for customs or export—is typically 2934999099, under “heterocyclic compounds with sulfur.” Regulatory understanding has grown in importance over the years, especially for international buyers. Safe logistics call for careful packaging—airtight, light-resistant containers—along with crystal-clear labeling for hazard communication. Anyone who’s handled bulk shipments of raw materials in a demanding environment can relate to how much depends on detailed paperwork and unambiguous labeling; miscommunication or regulatory slip-ups slow projects to a halt.
As a raw material, 5-chlorothiophene-2-sulfonamide finds its way into a variety of synthetic routes. Medicinal chemistry groups see value in the compound as a precursor for sulfonamide drugs, where its moieties provide unique pharmacokinetic properties. The electronics and specialty chemicals sectors take note of sulfur- and chlorine-substituted aromatics when looking to tweak material properties. In research settings, it’s turned toward the crafting of advanced ligands, dyes, or catalysts. I’ve seen this compound pop up unexpectedly as a side product in multi-step syntheses, only to realize a little planning could repurpose it for a parallel project, saving time and resources for everyone involved.
The environmental story of 5-chlorothiophene-2-sulfonamide deserves attention before it leaves the factory floor or research bench. As with many organic sulfur materials, the compound shouldn’t find its way to wastewater streams unchecked. Waste management calls for incineration or special chemical treatment. European and North American disposal standards ask for traceability and controlled destruction. Workers learn to treat spillage not just as a workflow problem, but as a responsibility to keep chemical contamination from local ecosystems. Sharing a workspace with colleagues over the years has hammered home the collective benefit of safe, responsible disposal protocols.
Supply chain interruptions, rising regulatory pressure, and tighter standards for chemical purities all add complexity to the life of 5-chlorothiophene-2-sulfonamide as a raw material. Production facilities struggle to adapt synthesis protocols amidst raw material price swings. Centralizing documentation and boosting real-time tracking of inventory bring some relief to purchasing departments. Digital material safety data platforms cut down on confusion and incomplete hazard communication, benefiting both the industry and the end-user. Looking ahead, greener synthesis—using less hazardous reagents or recycling process solvents—offers one of the few levers to reduce the compound’s long-term environmental footprint without sacrificing practicality.
