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Thiophene chemistry has quietly shaped the backbone of modern science for well over a century. When 2-thiophenecarboxaldehyde first came on the scene, researchers poked at sulfur-embedded rings with almost pure academic curiosity. Early synthetic chemists didn't have high-tech gear, so their discoveries took a mix of trial, sweat, and luck. Analytical tools in the twentieth century proved this little five-membered ring mattered far more than anyone guessed. Folks started to notice its knack for stepping into valuable reactions—especially when the push was toward pharmaceuticals, dyes, and complex organics. Over my years watching lab work evolve, there's always been a sense that the allure of heterocyclic compounds grew hand in hand with industry growth. By the turn of the millennium, you could find references to 2-thiophenecarboxaldehyde scattered throughout journals devoted to everything from electronic materials to agrochemistry.
You can't overstate the role compounds like 2-thiophenecarboxaldehyde play in laboratories. It’s a gateway structure—a well-fitting building block—and yet there's often limited chatter about it outside niche research meetings. My own experience with aldehydes, even those far removed from thiophene, showed how a stable functional group opens endless doors. Whether you’re investigating new drugs, tweaking conducting polymers, or analyzing natural product mimicry, this chemical's subtle reactivity paves the way. And it's not just curiosity—there’s a steady demand in industrial chemistry, medical research, and the ever-growing world of organic electronics.
2-Thiophenecarboxaldehyde presents as a pale liquid with that sharp, pungent aldehyde aroma—unmistakable on a lab bench. Its moderate boiling point and good solubility in organic solvents mean technicians find it straightforward to handle. Chemically, the molecule combines the aromatic stability of a sulfide-containing ring with the characteristic reactivity of an aldehyde. The sulfur atom brings unique electron density, altering both nucleophilicity and electrophilicity in reactions—something synthetic chemists constantly exploit. In my time working with aromatic heterocycles, I’ve seen just how much even a single atom tweak can change reactivity.
Any time I’ve unpacked a fresh bottle of 2-thiophenecarboxaldehyde in the lab, it’s been clearly labeled as hazardous. Suppliers usually offer purity levels above 98 percent, avoiding even trace water or oxygen-sensitive impurities. Common labeling on laboratory and industrial packaging includes hazard warnings for irritation, with signal words and pictograms by the Globally Harmonized System. This clear communication is a sign of progress over old glass bottles with cryptic handwritten labels. Worker safety improves when everyone trusts what’s in their flask.
Industrial and research syntheses of 2-thiophenecarboxaldehyde generally start from thiophene itself. I’ve watched chemists explore Vilsmeier–Haack formylation, which introduces that aldehyde group with a blend of dimethylformamide and phosphorus oxychloride. The method isn’t gentle—corrosive reagents, careful temperature control, and a vigilant eye for byproducts are needed. I remember the relief after chromatography columns revealed a clear separation between the desired aldehyde and over-reacted side products. The drive to 'green' up synthetic approaches has also spread, encouraging the use of milder oxidants and recyclable catalysts. Academic and industry chemists alike call this a win for safety and sustainability, even if yields can sometimes dip as a result.
One great thing about 2-thiophenecarboxaldehyde is the number of transformations possible at that reactive aldehyde position. I’ve seen it serve as a linchpin in making Schiff bases, where primary amines lock onto the carbonyl carbon. Reductive amination, Grignard additions, and even Wittig alkenylations all depend on the endurance and accessibility of this small molecule. The aromatic ring, meanwhile, doesn’t just sit idle—its sulfur atom allows for sulfonation, bromination, and Heck reactions under milder conditions than with benzene. In synthetic routes to pharmaceutical intermediates, engineers appreciate the flexibility and resilience of this backbone, often testing variations on protection-deprotection schemes to optimize downstream steps.
This compound occasionally hides behind different names in catalogs and scholarly articles. I’ve come across synonyms such as 2-formylthiophene, Thiophene-2-carbaldehyde, and even 2-Althioaldehyde in older literature. Smearing out these small differences matters more than you’d think; in complex synthesis, grabbing the wrong isomer burns both time and resources. Nowadays, clear Chemical Abstracts Service registry numbers and digital identifiers support better traceability, narrowing the once-wide gap between lab shorthand and commercial standards.
Experienced chemists treat 2-thiophenecarboxaldehyde with respect. I’ve seen its vapors irritate skin and mucous membranes almost instantly—not unlike many other small aldehydes. Proper ventilation and gloves aren't just guidelines, they’re non-negotiable. Most lab safety protocols flag it for fume hood use. Waste handling also follows a strict routine, collecting spent solutions and contaminated glassware in designated hazardous-waste bins. Industry compliance with local and international chemical safety laws reinforces this—ignoring the mandates on storage temperature or fire risk simply courts trouble. Organizations that prioritize regular safety training not only guard against acute exposure but also keep up with evolving regulations as new data rolls in.
Demand for 2-thiophenecarboxaldehyde continues to grow. Pharmaceutical research taps it for synthesizing potential drugs, especially those aimed at inflammation and neurological disorders. In the field of organic electronics, engineers value the sulfur ring for energy transfer and flexible conductance—qualities that pave the way for next generations of touchscreens, solar panels, and flexible circuits. Agricultural chemists also chase this compound for bioactive molecule development and crop protection studies. Universities carve out regular grants to test thiophene's versatility as part of ongoing green chemistry and bio-inspired catalysis research. I’ve seen first-hand how small investments in heterocyclic scaffolds launch careers and boost innovation pipelines across very different fields.
Innovation in this field rarely feels stagnant. Research groups worldwide continue to push the boundaries, using 2-thiophenecarboxaldehyde as a core intermediate in medicinal chemistry, advanced materials, and sensors. One rising trend focuses on its assembly into polymers that respond to light, temperature, or chemical triggers—laying groundwork for 'smart' materials. Another area heads into drug discovery, where libraries of thiophene derivatives tease out new leads against stubborn diseases. The collaborative model—pairing academic curiosity with industrial efficiency—fuels a steady flow of patents and peer-reviewed publications. It’s rewarding to watch postdocs and industrial chemists swap ideas at conferences, often inspired by a tweak at the aldehyde or sulfur site of this singular molecule.
Toxicologists keep a close eye on the reactivity of low-molecular-weight aldehydes. Existing studies report that 2-thiophenecarboxaldehyde, like its cousins, can pose inhalation and skin exposure risks. Chronic exposure questions remain, calling for deeper toxicokinetic profiling and workplace exposure limits grounded in actual lab and factory incidents. I’ve noticed more scientists joining up across disciplines, bringing in analytical chemists, biochemists, and medical researchers to paint a clearer picture. Balancing the benefits offered by this compound against potential long-term risks stands as a high priority. Risk mitigation in real-world operations—not just theory—is where progress sticks.
Looking forward, the future of 2-thiophenecarboxaldehyde points toward growth. Teams exploring organic semiconductors lean more and more on sulfur-containing heterocycles, pushing their stability and responsiveness for better device performance. Early results suggest these compounds might also support breakthroughs in stimuli-responsive polymers—think coatings that adapt to environmental changes or surfaces that self-heal after microscopic damage. At the same time, green chemistry voices continue calling for scalable, sustainable synthesis routes, which would trim reaction waste and lower the environmental toll. Long-term, medical research imagines more powerful, targeted drugs building off this aldehyde’s structure. Whether in startup labs or global companies, focusing on multi-disciplinary partnerships and strong safety cultures promises to keep 2-thiophenecarboxaldehyde both useful and responsible in the decades to come.
2-Thiophenecarboxaldehyde sounds like a mouthful, but at its core, it’s a starting material for making things that actually matter to everyday life. If you look beyond the white powder in the lab jar, this compound is a backstage player in some of the stuff people use or benefit from daily, even if most folks never hear its name.
Pharmaceutical chemists rely on 2-Thiophenecarboxaldehyde as a key building block when putting together new drug molecules. Look at how new antibiotics and anti-cancer agents come into the world—many require assembling pieces from smaller chemical parts. This compound, thanks to its reactive aldehyde group and the special sulfur-containing thiophene ring, lets chemists shape molecules that couldn’t exist otherwise. Drug discovery moves faster and smarter because of how this workhorse fits into chemical reactions, whether for antivirals, antihypertensives, or exploring something new in the lab.
Smell and taste involve more science than most realize. The unique structure in 2-Thiophenecarboxaldehyde creates a distinctive aroma, and that’s why the flavor and fragrance industries keep using it. It finds its way into formulas that mimic the scent or flavor of roasted, nutty, or even chocolatey notes. If you’ve sniffed a fancy candle or tasted a snack that seems to have a rich flavor profile, chances are some chemical handiwork like this went into those layers. Creating consistent results batch after batch means using reliable building blocks, and this compound offers that stability.
Startups and tech giants keep exploring organic electronics, and 2-Thiophenecarboxaldehyde helps shape molecules for these new devices. Organic LEDs, solar cells, and newer kinds of sensing devices depend on thiophene-based compounds for both flexibility and function. Researchers often push the boundaries of what’s possible because these starting materials give unique electrical properties. Sticking with old technology slows down innovation. Using building blocks like this puts newer, more efficient gadgets within reach sooner.
With all its potential, 2-Thiophenecarboxaldehyde isn’t free from scrutiny. Handling it safely matters—factory workers need training, labs require good ventilation, and environmental safeguards come into play when waste gets managed. Regulators care about where runoff goes and how exposure affects both people and nature. Smart companies invest in cleaner production routes and recovery systems, not just to follow rules but to cut costs and avoid headaches later on. Embracing green chemistry isn't just a buzzword; it means safer workplaces and less pollution, which real communities appreciate.
Next time someone hears about new medicines, tastier foods, or more advanced electronics, it’s worth remembering the chemical scaffolding supporting all that. 2-Thiophenecarboxaldehyde is one of those behind-the-scenes helpers. It underscores why paying attention to chemical supply chains, lab safety habits, and environmental impact never goes out of style. Making sure innovation benefits more people—without creating new risks—calls for honest talk, ongoing research, and sometimes changing old habits for better results.
2-Thiophenecarboxaldehyde might not show up at your typical neighborhood store, but in the world of chemistry, it’s a regular player in synthesis and research. The chemical formula is C5H4OS, putting together a ring of atoms that gives this compound its distinct characteristics. You find a sulfur atom sitting in the five-membered ring, replacing what you’d otherwise see as an oxygen in something like furfural. The molecular weight comes out to 112.15 grams per mole, a value that matters in both practical and research settings.
Chemical structures and formulas aren’t just numbers and letters on the chalkboard. Knowing the formula C5H4OS allows researchers and students to calculate exactly how much of this compound to use or produce in a reaction. Messing up the math can cost time and materials, not to mention research funding, which always seems to be in short supply. The molecular weight, 112.15 g/mol, provides the key for weighing out precise amounts. In practical terms, this means no guesswork, no shortchanging experiments, and no accidental waste.
In the lab, 2-thiophenecarboxaldehyde shows up when chemists want to build more complex molecules. Its structure starts with a thiophene ring—a five-sided arrangement that includes a sulfur atom. This ring brings useful properties for pharmaceuticals, agrochemicals, and materials science. Down to the basics, the aldehyde group on the ring’s second position lets chemists make all sorts of transformations, opening the door to larger molecules that can fight diseases or boost crop yields.
Quality research, especially in drug development, starts with understanding the molecular backbone. Small errors can lead to unexpected results or lead researchers down the wrong path entirely. I remember my early days in an undergraduate lab, when missing a hydrogen or miscounting a carbon was enough to wreck a synthesis or send a melting point off mark. Facts like a precise formula or weight turn uncertainty into confidence. That’s critical for big and small advances.
Laboratories face challenges when handling reactive aldehydes. These compounds can be unstable, especially if stored incorrectly or left exposed to moisture. Having accurate information—like C5H4OS and its weight—guides safe storage and handling. Labs benefit from clear labeling and standard procedures so that every technician, from the newest intern to the senior scientist, makes sure the material stays pure and ready for use.
Looking at safety, data like the formula and weight support proper inventory management, especially in regulated industries. Chemical databases and safety sheets need this level of detail so anyone picking up a bottle knows what’s inside and how to treat it. Digital inventory systems today rely on this factual information to keep track of what’s on the shelf, flag expiring stocks, and prevent losses.
Successful chemistry, whether applied or academic, rests on accuracy. We see too many shortcuts or casual attitudes with chemical data, but little mistakes carry big risks—lost batches, failed analyses, or even safety incidents. Emphasizing the right formula, C5H4OS, and its molecular weight leads to smoother research, less waste, and more consistent discoveries. In my own lab work, leaning on solid facts, not assumptions, has always prevented mistakes and paved the way for breakthroughs—even on an underappreciated molecule like 2-thiophenecarboxaldehyde.
2-Thiophenecarboxaldehyde serves as a useful building block in chemical synthesis, but it comes with risks many people overlook. Its sharp odor signals a compound that can easily irritate mucous membranes and skin. Researchers and lab workers who’ve spent time handling chemicals with similar sulfur and aldehyde groups will know how quickly spills or vapors can create headaches, both physically and logistically. That unpleasant smell lingers, and exposure warnings exist for a reason. Skin contact leads to irritation, and inhaling vapors induces discomfort, especially in tight workspaces. Eye contact is especially risky, making splash-proof goggles a small investment for peace of mind.
Letting bottles of 2-Thiophenecarboxaldehyde sit out in variable temperatures invites trouble. Cool, stable environments help preserve this compound’s integrity. I’ve seen stockrooms with fluctuating heat cause chemical degradation over months, leading to wasted inventory and unnecessary hazards. Direct sunlight should always be avoided, since photo-degradation doesn’t just spoil your chemical—it can also create byproducts nobody wants to inhale or touch.
Glass containers with tight seals work best. Soft plastics sometimes react over time, leaving microscopic residue or altering the chemical. Desiccators protect from excess humidity, as moisture influences the stability and can set off slow reactions, which later show up as sticky messes or foul smells.
In lab settings, I always put on nitrile gloves before opening bottles of pungent aldehydes—they don’t just offer an extra layer; they stop accidental transfer from glove to face or phone. Good fume hoods prove essential because aldehyde vapors won’t politely drift away—they build up and set off alarms, or at the very least, cause irritation. Splash shields also come in handy. Spills find a way to reach the eyes at the worst times, so never skip goggles.
Labeling matters. Sloppy handwriting or faded inks have delayed emergency clean-ups, especially in multi-user labs. Bold, clear labels prevent both confusion and accidents. Old habits like double-checking container integrity and updating inventory logs keep everyone safer, especially once you’ve seen what happens when someone grabs a bottle, assuming it’s something less reactive.
A few years back, a researcher in our group left a small bottle unsealed on a bench in hot weather. The entire room took on a rotten smell and left us trying to trace the leak for the better part of an hour. No one got hurt, but the sour memory persists—and so do the improved habits. Regular checks for seal integrity stopped similar incidents.
Another issue: mixing old, opened stock with new purchases led to unpredictable reactivity in some projects, spoiling weeks of work. Always keep older chemicals separate and discard bottles showing any change in appearance.
Training new team members on these routines saves more than money. Consistent use of PPE, fume hoods, and careful storage keeps the lab running without unnecessary interruptions or medical scares. I always advocate for routine audits of chemical stocks and storage conditions, not just for compliance, but because it only takes one oversight for a simple mistake to become a real setback.
If doubts arise, read through updated safety data sheets and ask manufacturers’ technical teams about any storage quirks. Staying informed beats dealing with an upgrade from minor to major incident. Looking after both your colleagues and your chemicals becomes second nature once you’ve experienced how quickly neglect can bite back.
Handling chemicals like 2-Thiophenecarboxaldehyde calls for real awareness. This liquid leaves a strong odor and a slightly yellow tint that catches your attention right away. In the lab, one whiff of this compound signals caution. Inhalation alone can trigger headaches and throat irritation. It irritates the skin, and if your eyes catch a drop, the sting sends you racing for an eyewash station. Safety data and my own time around aromatic aldehydes like this tell the same story: direct exposure packs a punch.
Nobody wants to cough through a shift, and I’ve seen colleagues forced to quit tasks to get fresh air after an accidental spill. While long-term data on cancer risk stays thin for many aldehydes, the hazard with these compounds often comes from immediate, sometimes severe, respiratory and skin issues. Open bottles send fumes into the air. And spills dry fast, making cleanup tricky. Swallowing shouldn’t even be a question—it’s toxic.
Flammability hangs over much of the work with 2-Thiophenecarboxaldehyde. Its vapors can ignite from a simple spark, even with an open flame out of sight. This isn’t just a backroom reminder; I’ve watched fire alarms blare after a flask toppled, evaporating on a hot plate nearby. Emergency teams never hesitate to treat this as a potential chemical fire. Fires involving this compound release toxic fumes.
Few think about runoff, but spilled or discarded 2-Thiophenecarboxaldehyde can seep into water or soil. Lab waste protocols emphasize storing it separately for disposal. Reports of aquatic toxicity highlight lasting environmental effects. In my college days, a poorly managed drain-tip led to trouble for local wastewater systems—and repeat visits from the safety manager.
Everyone in a chemistry lab or production room needs protection. At minimum, splash goggles, gloves made for solvents, and a lab coat form the first barrier. Proper fume hoods keep vapors away, while spill trays help limit surface contact. Never work solo with volatile aldehydes, as a fast response sometimes means the difference between irritation and a full-on medical visit.
Ventilation makes a difference you notice the moment you walk in. In tight quarters, using a compound like this without airflow lets vapors build to levels you can smell—which means you’re already at risk. Store it tightly sealed, in a cool spot, away from open flames or heat sources. Training matters even for those who think they’ve “seen it all.” I’ve relied on regular drills—fire, spill response, eyewash use—to keep myself and others ready for surprises.
Waste containers should be labeled, and mixing used solvents just to save space often makes things worse. Every chemical user has to respect the disposal guidelines set by their local authorities. My own habit is to double-bag, label, and ask questions if I’m not sure about compatibility.
Experience and training shape safe practices. It’s not just about following checklists—recognizing odor, knowing how your body reacts, and spotting risks before work starts all pay off. Lab teams build confidence not by luck, but by careful, consistent routines. Fact sheets and real stories spread lessons faster than rulebooks. If there’s been one lesson from years of working with reactive chemicals, it’s this: respect for the hazards keeps you protected every day.
A bottle labeled 2-Thiophenecarboxaldehyde rarely tells the whole story. This compound falls into the toolbox of many labs and factories, especially those tied to pharmaceuticals, dyes, and advanced materials. What sits inside those glass or plastic containers often makes a bigger difference than folks admit. Producers don’t always make one-size-fits-all batches, so you’ll find several grades floating around the market. Research grade, technical grade, and industrial grade show up with regularity. Someone with a bit of experience can tell there’s a world of difference hiding behind such simple names.
A little bit of background from my own days as a lab chemist: there’s nothing more frustrating than mystery contaminants in a reaction vial. A “technical grade” lot might fit the bill for a pilot run or some non-critical colorant project. On the other hand, a synthetic procedure heading for the next stage of an API (active pharmaceutical ingredient) can’t risk trace metals, sulfur byproducts, or water content floating in the mix. Lousy purity gives unreliable results, making calibrations and process optimization an uphill battle.
Published research backs up these headaches. A 2023 paper in Organic Process Research & Development pointed toward impurity cascades, where just a trace of extra sulfur dioxide upends downstream steps and gums up purification routines. Solid-state chemists, meanwhile, report that certain grades can sneak in enough water or solvent traces to cripple crystallization routines used to make organic electronics.
Companies often wrestle with the price tag. High-purity variants fetch a steeper fee, but skimping on quality sometimes launches a cascade of repairs, reruns, or regulatory pain. In pharma development, regulatory inspectors—think FDA or EMA—turn strict when an audit trails back to a questionable lot. Paperwork misses, incomplete certificates of analysis, or fudge-room in specs invite everything from failed trials to long delays in getting a drug to patients.
Folks driving pilot scale projects take another hit. Lower-grade batches might include stabilizers or residual solvents. These ghosts in the bottle can damage fine-tuned equipment or cause toxic byproducts. More than one facility manager has swapped horror stories about filters clogged or columns ruined by buying the wrong grade.
Trust builds from transparency. If you work in procurement or research, always ask for a certificate of analysis from reputable suppliers. These documents just might keep a whole project on track. Labs with solid quality management check incoming lots for critical impurities before triggering expensive or sensitive syntheses. Some teams set up small pilot reactions to flag impurities that analytical instruments miss. This hands-on approach saves headaches by sidestepping problems early.
Producers play an important role, too. Clear labeling and up-front information about assay values, trace elements, water content, and even packaging choices aren’t just nice-to-haves. They help everyone along the supply chain make informed, safe choices. The best suppliers respond quickly to tech questions and can offer custom purification for special needs.
Demand for precise, proven chemicals keeps growing across industries. As regulations tighten and client expectations rise, the drive for higher purity and clearer documentation looks set to continue. Anyone relying on 2-Thiophenecarboxaldehyde—whether in the lab or at scale—benefits from digging into grade details before the first weigh-out. Nothing replaces a sharp eye and a critical mind in chasing reliable results.
| Names | |
| Preferred IUPAC name | Thiophene-2-carbaldehyde |
| Other names |
Thiophene-2-carboxaldehyde 2-Formylthiophene Thiophen-2-carbaldehyde 2-Thienyl aldehyde |
| Pronunciation | /tuː θaɪˈoʊfɛn kɑːrˈbɒks.əl.daɪd/ |
| Identifiers | |
| CAS Number | [98-03-3] |
| 3D model (JSmol) | ``` 3Dmol:'CC1=CSC=C1C=O' ``` |
| Beilstein Reference | 1209243 |
| ChEBI | CHEBI:17829 |
| ChEMBL | CHEMBL226679 |
| ChemSpider | 17774 |
| DrugBank | DB04277 |
| ECHA InfoCard | 03fa1bba-e510-462e-8d92-aa9fa0588bfa |
| EC Number | 203-729-4 |
| Gmelin Reference | 7257 |
| KEGG | C05906 |
| MeSH | D013936 |
| PubChem CID | 7002 |
| RTECS number | XN8225000 |
| UNII | 496T8K7A3D |
| UN number | UN3439 |
| Properties | |
| Chemical formula | C5H4OS |
| Molar mass | 112.15 g/mol |
| Appearance | Colorless to light yellow liquid |
| Odor | Aromatic. |
| Density | 1.204 g/mL at 25 °C |
| Solubility in water | slightly soluble |
| log P | 1.73 |
| Vapor pressure | 1 mmHg (60°C) |
| Acidity (pKa) | 13.2 |
| Basicity (pKb) | 13.77 |
| Magnetic susceptibility (χ) | -37.3·10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.595 |
| Viscosity | 1.169 cP (25°C) |
| Dipole moment | 2.93 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 190.1 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -12.6 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -483.4 kJ/mol |
| Pharmacology | |
| ATC code | '' |
| Hazards | |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | H302, H315, H319, H335 |
| Precautionary statements | Precautionary statements: P210, P261, P280, P304+P340, P312, P305+P351+P338, P337+P313 |
| NFPA 704 (fire diamond) | 2-Thiophenecarboxaldehyde NFPA 704: 2-2-0 |
| Flash point | 62 °C |
| Autoignition temperature | 185 °C |
| Explosive limits | Explosive limits: 1.1–11% |
| Lethal dose or concentration | LD50 oral rat 1040 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral rat LD50 = 820 mg/kg |
| NIOSH | TTX5250000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | 0.1 ppm |
| IDLH (Immediate danger) | IDLH: 100 ppm |
| Related compounds | |
| Related compounds |
Thiophene 2-Thiophenecarboxylic acid 2-Thiophenemethanol 2-Thiophenemethylamine Bromothiophene Methylthiophene |
