2-Chlorothiophene is a chemical substance that falls under heterocyclic compounds, specifically those built around a five-membered ring that contains both sulfur and chlorine. The structure, C4H3ClS, places a chlorine atom attached at the second carbon of the thiophene core. Molecular weight clocks in at 134.59 g/mol, offering a specific chemical identity that distinguishes it as a building block for several industries. Looking at the product, 2-Chlorothiophene stands out for its manageable handling compared to some more finicky organosulfur analogs. Its distinctive odor, typical for chlorinated aromatic compounds, is immediately recognizable in the workspace, signaling both its presence and the need for thoughtful handling. The CAS Number for this substance is 96-43-5, and the HS Code used in international trade is 2934999099. The material forms a colorless to pale-yellow liquid at room temperature, though in colder settings it can appear as flakes or crystals. Density comes in at about 1.247 g/cm³ at 20°C, suggesting it sits slightly heavier than water, which matters for storage and separation practices. Solubility in water proves quite low, yet dissolves well in organic solvents like ethanol, ether, and acetone, which allows for flexible use across a range of synthetic needs.
The molecule itself features a planar thiophene ring with sulfur nestled between two carbons, and chlorine linked at the two-position. This layout gives 2-Chlorothiophene unique reactivity with nucleophiles, making it valuable in organic synthesis, especially in the design of pharmaceuticals and materials. Experienced chemists know that the chlorine atom not only directs reactions within the ring but also makes the compound a handy precursor for further functionalization. Specific gravity and vapor pressure, at 4.6 mmHg at 20°C, mean it vaporizes more readily than bulky solids, which can pose inhalation risks when used in unventilated spaces. Boiling point reaches 146°C, so distillation practices need robust control to keep exposure low and purity high. Melting point sits at roughly -40°C, eliminating the possibility of encountering this material as a solid under ordinary room conditions.
Handling 2-Chlorothiophene means encountering it in diverse forms, based on shipping, storage, and end-use. Bulk supply most often involves tightly sealed drums filled with liquid, though colder conditions can lead to crystallization, forming flakes or fine powders. Chemists see the shift between these forms as more than a visual curiosity—density changes have real effects on dosing accuracy, solvent selection, and blending practices. The ability to melt or dissolve the crystals back into liquid ensures adaptability in the production pipeline. Beads and pearls form only rarely, typically in specialized lab environments focused on fine-tuned reactivity or controlled-release systems. Each material form has its own density, flow behavior, and safe-handling profile, so attention to the physical state at each point in use guards against losses and unintended exposure.
Industry turns to 2-Chlorothiophene as a raw material in agrochemical manufacturing, pharmaceutical intermediates, and the creation of advanced electronics materials. The substance appears in the synthetic chain for active pharmaceutical ingredients that require halogenated thiophene backbones, as well as in the design of crop protection compounds and specialty polymers. The aromatic structure supports compatibility with numerous synthetic reagents, so manufacturers have room to explore new derivatives. Chemists who work with 2-Chlorothiophene know that trace impurities, moisture content, and certain residual solvents need tight monitoring to protect reaction yields and product quality.
Safety with 2-Chlorothiophene never gets overlooked, especially in large-scale chemical plants. This substance carries flammability risks due to its low flash point—roughly 38°C—meaning standard laboratory and factory environments require grounded equipment and vapor controls. Inhalation and skin contact can irritate tissue and upper airways, so standard operating procedures insist on protective gloves, goggles, and ventilated hoods. Spillage procedures call for non-sparking tools and absorbent material to contain liquid, then safe transfer to waste containers for disposal according to local chemical waste guidelines. Depending on exposure, acute and chronic health effects can arise, ranging from headaches to more serious respiratory irritation. Those who work with the material benefit from both training and clearly labeled container systems to prevent mixups and accidental inhalation. Material Safety Data Sheets (MSDS) remain a critical go-to resource prior to any handling or transfer activities.
Customs and tax officials rely on the precise HS Code 2934999099 to identify and track international shipments of 2-Chlorothiophene, keeping compliance above board and tariffs predictable. Importers and exporters who ship this product across borders must supply certificates of analysis, purity reports, and hazard documentation, as strict regulations for hazardous chemicals vary by location. I have seen weaker documentation delay clearances, so keeping detailed supply chain records ensures uninterrupted work for downstream users. Warehousing needs to feature specialized containers classified for flammable liquids, with inventory sequencing to limit stockpiling past expiration dates. Reliable manufacturers issue certificates to verify purity levels and trace residual solvent content, saving time in the quality assurance loop.
Reporting the molecular formula, C4H3ClS, provides an anchor for technical teams referencing stoichiometry during batch production. I have personally measured 2-Chlorothiophene density and vapor pressure to calibrate dosing equipment, as even small miscalculations can snowball into process hiccups or safety concerns. Chemists and process engineers turn to technical specifications—density, melting point, purity thresholds, boiling point, volatile content—at every step, matching the product profile with both experimental design and regulatory requirements.
Disposal of 2-Chlorothiophene and its derivatives calls for attention to environmental standards. Release into air, water, or soil can present hazards, as chlorinated organosulfur compounds may persist or undergo incomplete breakdown. Plant managers need solvent recovery systems, scrubbers, and sealed drains to keep fugitive emissions and liquid waste out of local ecosystems. Adopting closed transfer systems, vapor recovery, and container return programs prevent escape of both product and byproducts—all steps that help companies align with both environmental goals and regulatory mandates. Investment in onsite incineration or offsite hazardous waste treatment keeps the supply chain moving with less risk to neighbors or plant staff.
