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Benzenesulfonamide’s story traces back to the foundational days of organic chemistry when nineteenth-century chemists started tinkering with benzene derivatives. Folks like August Kekulé helped shape the understanding of benzene rings and set chemical research on its course. Benzenesulfonamide, formed by swapping a sulfonic acid group into benzene and capping it with an amide, found its first wave of relevance in the push for practical organic compounds. Researchers in the early twentieth century realized that sulfonamides did more than just sit on shelves; they helped treat bacterial infections, earning them a reputation as “miracle drugs” for a spell. The field of medicinal chemistry owes plenty to that generation of bench scientists who worked with stubborn glassware and rough reagents, laying the groundwork for today’s laboratory ease.
At its core, benzenesulfonamide is a white crystalline solid. Its formula reads C6H5SO2NH2—a benzene ring linked to a sulfonamide group. This small but structurally significant tweak sets it apart from plain benzene and gives rise to some useful characteristics. Unlike pure benzene, benzenesulfonamide doesn’t evaporate into the air easily, nor does it carry that familiar aromatic odor. If you leave it in a flask, you’ll see it doesn’t really budge until you heat it past 127°C, where its melting point sits. It stays put in water more than benzene does, since that sulfonamide group likes to draw in a few polar molecules. While the compound doesn’t behave with the reckless volatility of some benzenoid chemicals, it holds up well in storage and under typical handling conditions in labs.
Labeling benzenesulfonamide isn’t mysterious for anyone who’s spent time around chemical stockrooms. You’ll spot its name, CAS number, purity, and common synonyms like sulfanilamide or phenylsulfonamide. Many folks still use shorthand based on whatever department they worked in, remember it as “the white sulfa” or “benzenesulfo-amide.” Accuracy in labeling really matters for safety, and mistakes can land you in trouble when working with downstream chemical processes. Reagent grades, often measured by greater than 98% purity, stay rigid in standard technical specs to minimize the risk of contamination in both research and industrial processes.
Preparation starts with the sulfonation of benzene—a reaction that was a rite of passage in my own undergraduate lab. It begins with concentrated sulfuric acid introducing a sulfonic acid group to benzene, with heat applied over several hours. You wind up with benzenesulfonic acid, and that’s only halfway. To produce benzenesulfonamide, this acid gets reacted with ammonia or an amine, turning the sulfonic acid group into an amide. Industrial scale-up relies on similar steps, just with better control over temperature and the purity of reagents. Mistakes in timing or mixing can create a mess, emphasizing how important it is to respect reaction conditions.
Benzenesulfonamide presents an exposed amide nitrogen, making it a go-to starting point for chemists looking to customize the molecule. That nitrogen can accommodate alkyl or aryl groups, turning the base molecule into tailored pharmaceutical intermediates, dyes, and specialty materials. Those small substitutions on the amide go a long way in tuning the compound’s behavior—boosting solubility, shifting melting points, or making the molecule stick to certain proteins in drug research. That adaptability explains why benzenesulfonamide derivatives keep showing up in new patents and experimental drug pipelines.
Depending on which catalog or textbook you grab, you might see it called phenylsulfonamide, sulfanilamide, or simply “sulfonamide.” The pharmaceutical boom of the twentieth century saw sulfanilamide and its relatives sweep into use for antimicrobial therapy. That legacy sticks, and it’s not unusual to spot old product names in clinical literature or patent databases. For researchers sorting through decades of work, knowing these alternate names is part of the job—especially when hunting down critical references or comparing data across time.
Over time, laboratory and industrial standards for handling benzenesulfonamide have only gotten tighter. Direct contact with skin and eyes carries risks, as the compound, though not the most toxic in the cabinet, can still irritate or sensitize workers. That means gloves, goggles, and fume hoods are standard parts of the set-up in any modern lab. Regulatory frameworks in the US, Europe, and Asia include benzenesulfonamide on chemical inventory lists, tracking its movement for both environmental and human safety. Companies stay alert with proper labeling, training, and storage controls in warehouses and labs. I’ve seen seasoned chemists remind young researchers that what might look like a simple white solid can cause headaches if you ignore best practices—wisdom I still hold onto.
The reach of benzenesulfonamide stretches farther than a quick glance would suggest. Academically, chemists rely on it for organic synthesis and mechanistic studies. Drug developers look to its framework when designing sulfa drugs and newer antibiotics. Advanced materials researchers include it as a building block for customizing polymers, surfactants, and even liquid crystals. Agrochemical work and dye manufacturing often call for it as an intermediate, especially when precision and consistency matter for product performance. Those who work in wastewater treatment also check in on sulfonamide derivatives, given their persistence in environmental samples and the rise of analytical chemistry tracking traces in groundwater.
Research into benzenesulfonamide’s toxicity transformed the way labs view “benign” chemicals. While the parent molecule exhibits relatively low acute toxicity, certain derivatives pose problems for sensitive populations and the environment. Long-term studies shed light on the development of antimicrobial resistance tied to continued sulfonamide use, drawing new scrutiny as researchers look for smarter, safer alternatives. Analytical chemists now rely on sophisticated tools like LC-MS to study benzenesulfonamide residues in food and water, keeping tabs on human and ecological health. Those findings drive stricter disposal guidelines and spark new avenues for designing degradable sulfonamides.
Looking ahead, interest in benzenesulfonamide shows no sign of fading. Medicinal chemists continue to spin the molecule’s framework into next-generation antibiotics and anti-cancer compounds. Material scientists explore its properties as part of functional films and smart polymers. Green chemistry advances push for cleaner, more sustainable preparation methods, replacing harsh chemicals and minimizing waste. I’ve watched teams quietly challenge old assumptions as they test bio-based reagents and flow chemistry platforms to reduce exposure and environmental footprint. The legacy of benzenesulfonamide now ties into global health challenges, climate considerations, and the hunt for smarter pharmaceutical tools—proof that practical chemistry, when built on solid fundamentals, keeps finding ways to matter in new eras.
Benzenesulfonamide might sound like one of those chemicals buried deep in a textbook, but its uses reach into more parts of daily life and industry than most of us realize. Ever open a packet of medicine or use a cleaning product and wonder how those safe, stable compounds show up again and again? Compounds like benzenesulfonamide have a lot to do with that. Years ago, I saw it pop up not only in pharmaceutical news but also in industrial supply lists. It stuck with me as one of those unassuming building blocks that carry more weight than their bland names let on.
Pharmacy shelves these days carry countless drugs, and many rely on sulfonamides—a class benzenesulfonamide helped shape. Early on, sulfonamides became some of the first antibiotics on the market. These compounds target bacteria by blocking their ability to make essential proteins, giving the immune system support to clear tough infections. The main backbone for these agents draws from benzenesulfonamide, opening doors to variations that tune their medical effects. Synthetic tweaks to the benzenesulfonamide structure led to breakthroughs in treating everything from urinary tract infections to certain rare diseases.
Doctors might not write "benzenesulfonamide" on a prescription, but its chemistry sparks the active designs in drugs like sulfa antibiotics. Countless researchers keep studying its framework for novel treatments in diseases like diabetes, glaucoma, and epilepsy. That kind of versatility is rare. The medical value, backed up by decades of peer-reviewed research and clinical experience, proves how a single molecule can shape drug discovery for generations.
In factories, benzenesulfonamide shows up for even more reasons. Plastic manufacturers rely on it to craft specialty plastics; it gives flexibility and helps solve technical challenges without adding toxins that stick around in the environment. I’ve seen reports where shifting from heavy metals or older additives to compounds based on benzenesulfonamide cut down on waste and lowered risks for workers. Some flame retardants and dyes take advantage of its stability and compatibility with a range of other chemicals. Products stay safer and stronger longer because of these small choices in formulation.
Farmers benefit, too. Pesticides that deliver targeted protection against crop pests sometimes owe their efficiency to sulfonamide-based designs. The core of benzenesulfonamide makes it possible to create chemicals that don’t break down under sun or rain too quickly, providing steady results and reducing the need for frequent spraying. This helps preserve soil and water quality in the long run, creating a better balance between effective agriculture and environmental responsibility.
No story about chemicals fits without talking about health and safety. Like many organosulfur compounds, benzenesulfonamide can trigger allergies in sensitive folks. People with histories of sulfa drug reactions often steer clear of products tied to this family. Responsible manufacturers label their ingredients, and updated safety sheets guide both workers and the public on proper handling. Misuse and overreliance on related antibiotics have also driven resistance in hospital settings. Stewardship—making sure these materials do not get misused—calls for awareness on both the production floor and in clinics.
With tighter regulations and smarter green chemistry approaches, we can keep leveraging benzenesulfonamide’s benefits without repeating mistakes of past decades. That balance demands tough choices but offers hope for both healthier people and cleaner industries. Focusing research dollars into safer derivatives and alternatives, while strengthening recycling and disposal practices, will help keep this useful chemical in the roster of solutions instead of becoming another environmental burden.
Benzenesulfonamide, a name that pops up often in both chemical research and drug development, carries a straightforward formula: C6H5SO2NH2. This molecule brings together a benzene ring and a sulfonamide group, creating a structure with real-world value. I remember my first year in a chemistry lab, staring at models and trying to piece together atoms just like in this compound. It's more than just lines on paper—it’s a foundation for a whole class of medical and industrial compounds.
This compound might sound simple, but its role in medicine reaches far beyond its modest appearance. The core of sulfa drugs lies in sulfonamides just like this one. In the early 20th century, infections threatened life in ways we can barely imagine today. Doctors found real hope in sulfa drugs, which cut down the mortality from bacterial infections before modern antibiotics fully took the stage. It all starts with benzenesulfonamide as a building block.
As someone who has watched family members battle infections, I have a genuine appreciation for how one little molecule can mean the difference between a rough week and a hospital stay. Even today, chemists modify the base structure of benzenesulfonamide to create new antibiotics. In 2024, cases of resistance to classic drugs climb. Chemists go back to basics, look at molecules like this one, and study how new tweaks can restore antibiotic power.
Benzenesulfonamide packs its punch by bringing together a flat, aromatic benzene ring and a polar sulfonamide group. Structurally, the ring offers stability and the potential to attach new arms—chemists love that flexibility. The sulfonamide part interacts well with biological targets, making the molecule a starting point for many drug candidates.
Over a decade ago, I joined a research team looking at enzyme inhibitors for rare diseases. The team often chose molecules that mirrored the structure of benzenesulfonamide, because binding to enzymes meant better odds of stopping disease progression. Much of this hinges on the molecule’s dual nature: stable, yet reactive in the right spots.
Benzenesulfonamide leaves the lab and enters real worlds—wastewater plants, medicine cabinets, and even chemical manufacturing. It takes some careful handling. Factories that make dyes and pesticides use this compound. When not managed well, these substances can slip into rivers and impact aquatic life. My city once faced a warning when traces of sulfonamide compounds hit the treatment plant, triggering a review of local manufacturing.
There are routes to safer water and cleaner processes. Factories now set up better filtration, treatment, and tracking of chemical runoff. Researchers investigate greener ways to make benzenesulfonamide from renewable materials. Newer regulations help keep misuse in check, promoting both chemical discovery and environmental health.
The blend of stability and utility in benzenesulfonamide makes it invaluable. From hands-on experiences in both labs and daily life, I see that understanding a molecule’s formula isn’t just for textbooks. Society gains most when scientific progress keeps pace with health and environment. Clear knowledge, responsible use, and ongoing research turn a chemical formula into a positive force.
People sometimes expect all small molecules with nitrogen and oxygen to blend right into water. Benzenesulfonamide flips that idea on its head. It brings together a benzene ring, notorious for keeping out water, with a sulfonamide group, which actually loves a good splash. The battle between these parts means you get a compound that doesn’t play by the usual rules of “dissolve or bust.”
The structure matters. That benzene ring acts stubborn, dragged down by weak interactions with water molecules. The sulfonamide side, with its polar components, tries to bond with water via hydrogen bonds. In reality, the ring dominates. Water struggles to pull benzenesulfonamide apart at the molecular level. If you sprinkle some into a glass of water, you’ll notice cloudy specks long after a good stir.
This isn’t just a quirky chemistry fact. I’ve seen researchers waste hours trying to get it to dissolve, expecting swift results like with table salt. Poor water solubility changes the game for anyone in pharmaceuticals, environmental testing, or chemical synthesis. When a substance doesn’t dissolve, results come back inconsistent. Dosages for medicines lose reliability, reactions limp along halfway, and it’s tricky to detect anything in water samples.
Medications need solubility. Poorly soluble compounds force chemists to add solvents or develop alternative formulations. Drug development slows, costs go up, and sometimes promising medicines get shelved. In water treatment, if a contaminant like benzenesulfonamide clings to its solid form, standard filtering or purification methods might miss it. People trying to track pollutants or break them down run straight into this solubility wall.
Take a look at laboratory data and you find agreement. Benzenesulfonamide dissolves in water at about 5 grams per liter at room temperature—far lower than simple salts or some small acids. The actual process feels slow, sometimes needing extra heat or stirring. Compare that to fully water-loving compounds, and it’s clear that benzenesulfonamide drags its heels in every trial.
Why so low? The benzene ring stays hydrophobic and shields much of the molecule from interacting with surrounding water. The sulfonamide group helps somewhat, but not enough to balance everything out.
I’ve learned from experience that you can get around this stubborn solubility with some smart techniques. Use organic co-solvents like ethanol, DMSO, or methanol—these break up those tight hydrophobic rings and push water to accept the molecule. Careful heating will nudge up the solubility, but watch out for decomposition. In labs, grinding benzenesulfonamide into a powder before mixing improves contact with water, helping a bit. Still, none of these tricks make it as easy as working with pure salts or highly polar molecules.
Industries committed to innovation try new approaches: pairing benzenesulfonamide with cyclodextrins or surfactants to help move it into water-based systems. Formulation scientists develop nanoparticle-based suspensions to help the molecule dissolve and work as intended in biological tests. These solutions take money, testing, and iteration, but they crack part of the code.
Knowing about benzenesulfonamide’s struggles with water sets realistic expectations. Chemists, pharmacists, and environmental scientists save time, skip trial-and-error, and choose smart workarounds. If the solubility still isn’t enough, other analogs with extra polar groups or a different backbone bring water compatibility back in reach.
People use data and open problem-solving every day to work past the natural limits of molecules like benzenesulfonamide. Nothing beats a bit of curiosity and perseverance for turning insoluble odds into usable outcomes.
Benzenesulfonamide means business in any chemical lab. It’s not just some academic reference point—this is a compound you’ll see in pharmaceutical work, agrochemical research, and even dyes. With stakes like these, ignoring proper storage can ruin years of work, waste money, and potentially put people in danger.
Some chemists get lazy and leave bottles out on benches or toss them into storage without a second thought. That’s never smart, especially with organosulfur compounds. Benzenesulfonamide needs a dry and cool place. Humidity isn’t just a small nuisance—the compound breaks down if it absorbs moisture. Even if you don’t see instant changes, you could later face inconsistent lab results or more costly rework.
From my own work, I remember a grad student who stuffed dry chemicals near a window. After a single summer weekend, the crystals had clumped together. They still looked okay, but the melting point test told another story. Impurities from water uptake had contaminated the lot, and the student had to start again—losing a month of effort.
A plastic lid or loose cap isn’t enough. Laboratory-grade benzenesulfonamide comes sealed, and there’s a reason. A tight screw cap and a strong glass or HDPE bottle keep out humidity and air. Anyone who’s worked long enough in chemical storage knows even small leaks add up over time. Glass bottles do a solid job against diffusion, and plastics like HDPE resist chemical leaching.
Keep these bottles away from flammable liquids or strong acids. Benzenesulfonamide keeps stable under the right conditions, but nobody wants a risk of unwanted reactions. Store it well above ground level, away from heat sources or sunlight, to avoid temperature spikes that drive up degradation. For reference, room temperature—around 20–25°C—works, but lower temperatures extend shelf life.
A clear label isn’t busywork. Proper labeling with full compound name, date received, and hazard symbols protects everyone in the lab. It saves time and avoids confusion. Without labels, mixing up benzenesulfonamide with a similar-looking compound isn’t just embarrassing—mistakes like these can halt a project or trigger serious safety issues.
Studies like those from the American Chemical Society consistently show that exposure to humid environments diminishes the purity of benzenesulfonamide samples. Even small traces of water cause hydrolysis reactions, affecting performance in later syntheses. Manufacturer guidelines from Sigma-Aldrich or Thermo Fisher underline the importance of storing in "tightly closed containers, in a cool, dry place." That advice is based on testing, not guesswork.
Dedicated desiccators work best for long-term storage, especially for research labs. If you’re not using chemicals regularly, break up large stocks into smaller amounts. This way, you aren’t constantly exposing the entire batch to air. Fresh silica gel packs near the bottles also soak up stray moisture.
Lab budgets always get squeezed, but cutting corners on storage turns out expensive in the long run. Old chemicals lose value fast, and replacements chew through time and grant money. Investing in good shelves, correct bottles, and labeling beats struggling with contaminated samples or failed experiments. Benzenesulfonamide won’t complain—but if neglected, it’ll take its toll eventually.
Benzenesulfonamide comes from a blend of chemistry and industrial processes. This compound shows up in the lab as a white, crystalline solid. You’ll mostly spot it in research, chemical manufacturing, and, at times, as a building block for certain drugs or dyes.
Folks working directly with chemicals quickly learn to respect any substance, especially one with a name that long. I remember reading lab safety sheets before handling even a pinch of it during my university days. Direct skin contact or letting dust fly around into the air is a real worry, especially over hours or days. Anyone who’s spilled chemicals on their fingers knows that irritation or rashes aren’t something you brush off.
Studies point out that benzenesulfonamide can cause mild irritation to skin and eyes. Some research done on animals highlights temporary discomfort after direct application, but not much beyond that. Most folks outside of labs won't get exposed to enough of it to see any problems unless someone’s careless about gloves, masks, or ventilation.
Talking toxicity, benzenesulfonamide doesn’t pack the same punch as heavy metals or more notorious chemicals like benzene. Acute toxicity sits on the lower side, with large amounts required for serious harm. People on manufacturing floors or in academic labs run the most risk, mainly if safety habits slip or spills get ignored. There’s no strong evidence showing this compound triggers cancer, birth defects, or changes in genes. Regulatory agencies in Europe and North America agree: handle with care, but don’t panic.
Agencies like OSHA and the European Chemicals Agency call for common-sense measures: good ventilation, gloves, and eye protection. These rules don’t come out of nowhere; they come from decades of tracking workers’ health and chemistry accidents. Most warnings boil down to not treating the powder like talcum or sugar. The real avoidable danger comes from inhaling fine dust, so lab hoods and dust masks matter.
Garbage doesn’t stop being a problem when you throw it away. Waste from chemical manufacturing often lingers in soil or water in industrial neighborhoods and, if nobody’s careful, can wreak havoc on local wildlife. Right now, there’s little proof that benzenesulfonamide causes major environmental damage the way oil spills or pesticides do. Some byproducts, or accidental high-concentration leaks, could harm small aquatic critters or plants if no one’s paying attention to disposal.
Chemical safety always runs on respect and good routines, not fear. Companies keep chemical risks manageable by following solid handling procedures. I’ve watched old-school chemists spend more time on cleanup than the reaction itself—unexciting, but it’s how accidents get avoided. Reminding young scientists or new workers about careful storage, good airflow, and washing up after handling keeps everyone safer, every shift. Basic training, regular equipment checks, and transparent reporting when something splashes or spills help a community of workers stay healthy and keep risks low.
Getting rid of leftover benzenesulfonamide takes more than flushing it down the drain. Hesitation to spend money on safe waste processing creates long-term messes. Industry can always step up by investing in modern treatment systems and keeping open channels with local regulators. Making lab and factory safety a team goal, not just a line in a manual, marks the real solution for any chemical—benzenesulfonamide included.
| Names | |
| Preferred IUPAC name | Benzenesulfonamide |
| Other names |
Benzenesulphonamide Sulfanilylbenzene Phenylsulfonamide Benzenesulphonamide |
| Pronunciation | /ˌbɛnˌziːnˌsʌl.fəˈnæm.aɪd/ |
| Identifiers | |
| CAS Number | 55-21-0 |
| Beilstein Reference | 1720299 |
| ChEBI | CHEBI:22743 |
| ChEMBL | CHEMBL1427 |
| ChemSpider | 2141 |
| DrugBank | DB06730 |
| ECHA InfoCard | 05c1d19b-818e-4855-86a6-02a6cb8abd3a |
| EC Number | 205-525-2 |
| Gmelin Reference | 82107 |
| KEGG | C06591 |
| MeSH | D010695 |
| PubChem CID | 8451 |
| RTECS number | DB6650000 |
| UNII | G0ZB8I1EMX |
| UN number | 2811 |
| CompTox Dashboard (EPA) | DTXSID9020639 |
| Properties | |
| Chemical formula | C6H7NO2S |
| Molar mass | 155.19 g/mol |
| Appearance | White crystalline solid |
| Odor | Odorless |
| Density | 1.28 g/cm³ |
| Solubility in water | Slightly soluble |
| log P | 0.68 |
| Vapor pressure | 0.0000133 mmHg at 25°C |
| Acidity (pKa) | 10.1 |
| Basicity (pKb) | 14.30 |
| Magnetic susceptibility (χ) | -52.2×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.676 |
| Viscosity | 2.06 mPa·s (at 80 °C) |
| Dipole moment | 3.5 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 203.2 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -91.0 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -1630 kJ/mol |
| Pharmacology | |
| ATC code | S01CA01 |
| Hazards | |
| Main hazards | May cause eye, skin, and respiratory tract irritation. |
| GHS labelling | GHS07, Warning, H315, H319, H335 |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | H315: Causes skin irritation. H319: Causes serious eye irritation. H335: May cause respiratory irritation. |
| Precautionary statements | Precautionary statements: P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P337+P313, P403+P233, P501 |
| NFPA 704 (fire diamond) | 2-1-0 |
| Flash point | 132 °C |
| Autoignition temperature | 500°C |
| Lethal dose or concentration | LD50 oral rat 2,500 mg/kg |
| LD50 (median dose) | LD50 (median dose): 2560 mg/kg (oral, rat) |
| NIOSH | RN994-59-2 |
| PEL (Permissible) | Not established |
| REL (Recommended) | 5 mg/m³ |
| IDLH (Immediate danger) | Unknown |
| Related compounds | |
| Related compounds |
Benzenesulfonic acid Sulfanilamide Sulfanilic acid Sulfanilamide derivatives Sulfonamide p-Toluenesulfonamide |
