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Chemists first explored the acyl chlorides family in the 19th century, and N-Butyryl Chloride eventually emerged out of growing demand in organic synthesis. Industry recipes kept shifting, starting from simple chlorination approaches before WWI up to the more controlled processes used now, which grew from advances in purification and material handling. Over the years, interest surged as more groups needed specialty intermediates for pharmaceuticals, agrochemicals, and flavors. This chemical once demanded careful handling due to limited safety protocols, but modern standards developed as incidents taught lessons about chemical exposure and proper ventilation. Today’s production reflects a history where risk, need, and chemical know-how forced the hands of both researchers and manufacturers.
N-Butyryl Chloride belongs to the acid chloride club, with the butyryl group tethered to a reactive chlorine atom. Known for its pungent smell and aggressive tendency to react with water, this compound keeps a spot on the shelf in labs and industrial plants. Industrial giants distribute it mainly as a colorless to light yellow liquid housed in tight-seal drums, labeled with clear hazard warnings. It finds a loyal market in both large scale synthesis and specialty work, trusted for reliably introducing the butyryl group onto many chemical structures. Clients often expect a high-purity profile, with water sensitivity pushing for airtight packaging and swift usage after breaking the seal.
You won’t miss N-Butyryl Chloride in a room. The vapors hit your nose quickly, working as a sharp warning system. Boiling at about 104°C and melting at -80°C, it flows freely at room temperature but evaporates quickly if spilled. It easily hydrolyzes in air, producing butyric acid fumes and hydrochloric acid, both producing harsh odors and irritation. The molecule sits at a molecular weight of about 106.5 g/mol, and its density of approximately 1.02 g/cm³ matches expectations for an acyl chloride. Flammability becomes a concern as vapors linger, especially near open flames or electrical sparks.
Commercial shipments of N-Butyryl Chloride hit the road or rail under tightly governed rules. Labels usually flag the United Nations number UN 1759, and the “Corrosive” warning stands out on shipping containers. Most suppliers supply a certificate of analysis, confirming purity that typically hovers at 98% or above, and companies keep a sharp eye on details like residual acidity and color. Regulations push for secondary containment, clear hazard pictograms, and data sheets that explain correct storage conditions—away from water, direct sunlight, and humidity.
Manufacturers lean toward the traditional reaction of n-butyric acid with thionyl chloride, producing N-Butyryl Chloride alongside sulfur dioxide and hydrogen chloride. The process thrives in glass-lined reactors under inert atmosphere, as water in the air can waste thionyl chloride and trigger dangerous fumes. Refined processes include using phosgene, but the hazards steered most companies toward thionyl chloride or oxalyl chloride for safety and waste reasons. The crude product receives careful distillation to remove color bodies and trace acids, producing a clear, nearly colorless liquid packed in small batches under nitrogen.
N-Butyryl Chloride wins attention thanks to its acylating muscle. In the hands of medicinal chemists, it turns alcohols and amines into esters or amides, bringing new biological activity to target molecules. Its reactivity proves useful—for example, in modifying sugars, peptides, or even the backbone of drugs to change their absorption and half-life. Polymer chemists tweak polyester backbones or introduce pendant groups. The catch is its affinity for water—any stray humidity ruins yield and clogs up glassware with stubborn, stinky solids. Even small mistakes mean harsh byproducts, so labs investing in this chemistry need rigorous practice to keep water out and reagents dry.
Shoppers in the chemical marketplace know this compound by several monikers: n-Butanoyl chloride, 1-Butanoyl chloride, and sometimes just butyryl chloride. It’s easy to spot on company price lists as n-Butyroylchloride and butanoyl chloride. Different languages and catalogues juggle subtle spelling shifts, but all refer to the same volatile, corrosive liquid, with clear overlap in CAS number searches.
Anyone moving, storing, or using N-Butyryl Chloride quickly becomes aware of its hazards. Direct contact stings skin and eyes, and inhaling those dense fumes burns airways. Most companies push for full personal protective equipment—gloves, goggles, lab coats, and fume hoods. Emergency protocols demand eyewash stations and safety showers nearby. In my own experience, handling it means budgeting extra time for careful transfers and venting off-gas into scrubbers, never out an open door. Standards from groups like OSHA and the European Chemicals Agency mandate regular safety training and incident reporting, and many workplaces build these rules into routine lab checks.
Industries that churn out pharmaceuticals, crop protection agents, and fragrances rely on N-Butyryl Chloride as a starting point for transformation. This chemical lets project teams tweak molecules for better drug performance, longer shelf-life, or added scent complexity. Hospitals owe some key antibiotics and anesthetics to reactions that install a butyryl group using this reagent. Plant scientists count on it to synthesize herbicides madeto resist soil breakdown and improve crop yields. Flavors and fragrances use small doses to lock in notes that are otherwise unstable, helping perfumes linger and flavors pop.
Current research stretches the use of N-Butyryl Chloride far outside its old role in bulk acylations. Novel surfactants, designer polymers, and complex natural product syntheses now rely on this building block to introduce bio-compatible handles. Research groups tune reaction conditions to reduce byproducts, improve yields, and even recycle surplus byproducts like butyric acid. Interest grows in eco-friendly methods replacing thionyl chloride or phosgene with less hazardous activation strategies, which promises to lower emissions and shrink the environmental footprint.
Toxicology teams give N-Butyryl Chloride a wide berth for good reason. Animal studies show inhalation and skin absorption quickly irritate tissue, and repeated exposure can cause respiratory distress, chemical burns, and other chronic effects. Agencies classify it as a strong irritant and corrosive, warning against all but the most necessary handling outside contained areas. Chronic toxicity data remain sparse, but the acute risks are real—spills, faulty storage, and improper handling have sent workers to the hospital in documented industry incidents. Waste disposal and spill cleanup require trained hands only, and medical staff treating exposures focus on decontamination and respiratory support.
Looking ahead, safer manufacturing and handling methods top industry wish lists. Automation can cut down human exposure, and green chemistry approaches hold promise—teams explore new reagents that deliver the same butyryl group using milder, non-chlorinated pathways. Regulatory tightening and better emissions controls nudge even established players toward cleaner processes. Market trends in biotech and custom molecules continue to push demand, especially as new drugs and materials demand precise chemical tailoring. The balancing act sits between performance, safety, and sustainability, with researchers, production engineers, and regulators teaming up to find solutions that keep risk, waste, and cost in check.
N-Butyryl chloride doesn’t turn heads unless you’ve got a hand in certain industries. This clear, biting chemical works behind the scenes in labs and factories, shaping some of the stuff that winds up in consumer goods, pharmaceuticals, and even agriculture. I’ve worked with a few of these applications, and it’s easy to overlook how chemicals like this one carry a lot of responsibility—and risk. Knowing what it does and where it ends up matters, especially as new safety and environmental standards come into focus.
One of the main jobs for n-butyryl chloride: acting as a building block in drug making. Chemists use it to change the structure of molecules, basically giving them a custom-tailored suit so they fit their purpose. In real terms, a batch of antibiotics or anti-inflammatory drugs you pick up at the pharmacy probably owes some of its effectiveness to reactions kicked off by this chemical. Research shows acyl chlorides like this one let drug makers produce certain compounds more efficiently, sometimes boosting yield or purity—which means lower costs and better access. With drug shortages and pricing on everyone’s mind, every detail counts.
Beyond medicine, you’ll spot n-butyryl chloride upstream of pesticides in agriculture. It helps build the molecule shapes that fend off bugs or fungus, offering farmers more control over their crops. This means steady food supplies, and when the right safety checks are in place, less environmental damage. But improper use sparks public health concerns. We’ve seen cases where runoff introduces breakdown products into water sources or soil. Tougher oversight pushes companies to adopt cleaner practices or use alternative chemicals, but that work’s not done yet.
Fragrances and specialty plastics sometimes get a boost from this compound, too. If you’ve ever wondered why a scent lingers or a piece of plastic flexes just so, modified acids like this one make a real difference. The process involves attaching acyl groups—the basic units to tweak properties or lengthen shelf life of a product. These benefits have to be balanced with stability and safety, especially for household goods or materials that touch food.
Handling n-butyryl chloride means coming face to face with corrosive fumes and a substance that goes wild if it meets water. That reality has shaped strict handling procedures in factories and trucks. Workers rely on full gear—gloves, goggles, ventilation—to keep exposure low. Regulatory agencies track usage through permits, and spills require immediate action with trained response teams. Accidents still happen, highlighting the need for ongoing training and smarter facility design.
As chemical regulations evolve, companies investing in safer alternatives reduce risks for everyone. Green chemistry initiatives encourage replacing hazardous substances or reusing them in closed systems, minimizing waste. Some labs have already moved to less reactive acylating agents, especially for large-scale syntheses. Research into flow chemistry, for example, lets reactions happen under more controlled conditions, limiting exposure and cutting down on unwanted byproducts.
Communities benefit when industry and regulators develop better data sharing about where and how chemicals get used. Updated safety data, transparent supply chains, clear labeling, and education for workers make the risks more manageable. Consumers still don’t see n-butyryl chloride on store shelves, but its fingerprints appear in countless products. Demanding higher standards and supporting companies that invest in safety pushes progress in the right direction.
Anyone who’s opened a bottle of N-Butyryl Chloride remembers it—the sharp, biting smell that makes you step back. It’s not just unpleasant; it signals real risk. This chemical likes to react with moisture, releasing hydrochloric acid fumes. You catch a whiff, and suddenly your nose burns, your eyes water, maybe your lungs tighten. If you’ve stood over a bottle too long, you know those signals tell you something matters: this stuff’s dangerous, even at low concentrations.
Let’s start with basics. Splash goggles are non-negotiable—the kind that seals around the eyes, not those flimsy things that sit like sunglasses. I learned this lesson after seeing a coworker run for the eyewash station because his safety glasses left gaps. Chemical-resistant gloves make a difference too. Nitrile works; latex does not. Your skin will thank you later. Full-coverage lab coats and, if you’re especially cautious, a chemical apron, help prevent those accidental spills from soaking into clothes. Closed shoes don’t just protect against drops—they keep splashes from getting to your skin.
Some chemicals warn you by smell, but N-Butyryl Chloride gets sneaky; the vapors may dull your senses before you notice. Always stick to a chemical fume hood. Just because a room smells clean doesn’t mean it’s safe. Poor ventilation led to a mess at our lab—coughing workers, another scramble for clean air. Fume hoods solve most of this. Glove boxes work for tiny quantities, but you rarely see that outside high-precision labs.
You don’t just stick the bottle on a shelf. N-Butyryl Chloride breaks down with water, so humidity ruins it—and risks leaks or explosions. Keep containers sealed tightly, in a cool, dry, and well-ventilated spot. Acid cabinets work best. Metal shelving can corrode fast if vapors escape, which happened once at my old workplace. Don’t store near bases or alcohols; those ignite violent reactions. Even glass should be checked for old cracks, just in case.
If a spill happens, don’t panic. I’ve seen folks run for buckets of water out of habit—bad idea, since water kicks off a dangerous reaction. Absorb small spills with dry sand or inert absorbents, never paper towels or rags. For larger events, evacuate until the area clears out, then send in the trained crew. Cleanups work smoothest with spill kits stocked for acids. Litmus paper helps check if the area’s neutral.
Safety manuals work only if you’ve read them. Run drills. Know where the eyewash and shower sit, and keep them accessible. I keep a routine: before using N-Butyryl Chloride, I set out emergency numbers and check equipment. Even the old-timers benefit from refreshers. Nobody wants to be the person learning what to do mid-crisis.
Alternatives pop up every couple of years—less volatile acyl chlorides or green chemistry swaps. Not every lab can make the switch, but the conversation matters. When substitutions don’t work, tight protocols and real respect for the risks protect both people and projects. Every person in the lab plays a role. Strong safety culture comes from shared responsibility, not just compliance.
N-Butyryl chloride shows up as a clear, colorless liquid with a sharp and irritating smell. The chemical formula for this compound is C4H7ClO. That means it contains four carbons, seven hydrogens, one chlorine, and one oxygen. Its molecular weight comes out to about 106.55 g/mol. This number gives chemists and workers an idea of how much a specific amount of the compound will weigh when measured in the lab or on the production floor.
Knowing the chemical formula and molecular weight turns out to be more important than it seems for both safety and practical use. Speaking from experience, handling chemicals in school and lab settings always starts with the formula. It directs every decision about storage, compatibility, and usage. For example, the presence of chlorine in N-Butyryl chloride signals a warning—this compound reacts strongly with water and alcohols. A spill or accident can quickly fill a room with dangerous HCl fumes. These immediate dangers make the basic knowledge about its chemical identity a top job for anyone working with or around it.
N-Butyryl chloride finds a place in many chemical syntheses. Pharmaceutical plants reach for it while making antibiotics, anti-inflammatory drugs, and more. It forms part of the toolset for building other compounds since its butyryl group can be swapped or attached to various molecules. Labs also use it to create specialty chemicals or agrochemicals. But with its aggressive behavior around moisture, strict handling measures step in. Companies train their team members, supply vents and masks, and keep the substance safe from even a bit of water.
Manufacturing sites sometimes report spills and accidents, and public data shows that mishandling acyl chlorides such as N-Butyryl chloride leads to injuries. Many of these could have been dodged with a stronger focus on education and preparation. Every bottle should be labeled with its formula, not just its name, to avoid mix-ups. Emergency responders and waste handlers also benefit from this basic information. It’s not just a technical detail—it’s a key to staying safe.
Mistakes with reactive chemicals usually come from shortcuts or inattention. In practice, a few solutions make a difference. Updated training helps staff recognize chemical names, formulas, and what to do if something goes wrong. Always reading the safety data before opening a container saves headaches. Pair this with proper storage—locked cabinets, clear labels, and dry environments. If something spills, quick action with an emergency protocol reduces harm. A digital system to log and trace every use of N-Butyryl chloride, from the supplier’s warehouse to the waste facility, adds another safety layer.
Anyone—from chemistry students to full-time technicians—benefits from understanding as much as possible about the chemicals in play. The chemical formula and molecular weight for N-Butyryl chloride may look like dry facts on a label, but they are stepping stones to safer work and smarter decisions. Those details open the door to thinking ahead about risks, making better responses in a crisis, and reducing the chance of accidents in both small labs and large factories.
N-Butyryl chloride brings some real teeth to the lab or production space. Its sharp, stinging odor hits the nose before anything else, and a little contact with moisture in the air can fill a room with an aggressive cloud of hydrogen chloride gas. I’ve watched even seasoned colleagues jump away from a bottle of N-Butyryl chloride that wasn’t capped tightly enough. This stuff will chew through a shelf if left unchecked. Precaution isn’t just good practice; it’s self-preservation.
Let’s get one thing clear: N-Butyryl chloride reacts fast with water and lets off dangerous fumes, especially when humidity creeps in. Regular flammable or corrosive cabinets won’t cut it. I always insist on a dry, cool spot, usually a tightly sealed steel or glass container with a fitted cap. I keep any acids and bases far from the area, since accidental mixing spells disaster. Even spillage on a glove can eat through it in minutes. People might assume all chemicals behave the same way, but N-Butyryl chloride takes any shortcuts as an invitation to havoc.
One mistake I saw early in my career was someone storing N-Butyryl chloride without a vented cabinet. They thought the bottle’s cap would do all the work. Next thing, the cabinet reeked so badly that nobody wanted near it. Good airflow keeps vapors from reaching dangerous levels. Fume hoods or ventilated enclosures serve as real insurance against accidental inhalation. My rule: if you wouldn’t open a bottle in the open room, don’t let a leak grow in an unventilated storage unit.
Nobody wants to hunt for labels through a crusty old cabinet. Everything should stand out: clear tags, date stamps, and warnings. I’d rather hear a new staff member groan about reading a wall of warnings than fumble with an unmarked container. Regular checks trim down confusion. If I find a bottle missing a label — trash bin, no questions. Better to start fresh than nurse a mystery chemical. Digital tracking helps, but I keep a handwritten log taped inside the cabinet for quick checks.
Storing chemicals never becomes routine, especially the dangerous ones. You learn early to check for leaks, tight caps, and the condition of the bottle itself. Glass containers can corrode from the inside when chemicals break down, so I swap out old stock even if there’s liquid left. Waste some product, sure, but nobody wants to risk handling unknown byproducts. I’ve worked under supervisors who cut corners and trust simple procedures to do the job. That’s where accidents creep in. I never forget the time a bottle cracked after a year on the shelf, spilling fumes everywhere. Regular reviews of safety data keep the process fresh in my mind.
It’s easy to overlook the basics once routines set in. A few steps always pay off: choose airtight glass or steel, secure the container upright, and add extra protection (like a plastic tray or spill container) to catch any drips. Periodically test cabinets for airflow and check for corrosion. Keep emergency equipment within reach, and train everyone who handles the material. N-Butyryl chloride doesn’t forgive mistakes. A culture of attention, reinforced by direct experience, stands as the real foundation for safe practice.
N-Butyryl chloride gets used in making pharmaceuticals, plastics, agrochemicals, and dyes. It’s a chemical that burns the skin, damages the eyes, and chokes anyone unlucky enough to breathe its fumes. Its reactive appetite for water means it releases corrosive hydrogen chloride gas on contact with moisture. People working in small labs or large plants run the risk of hurting themselves or their community if they treat this chemical lightly. At some point, containers, spills, and leftover stock all need a smart, cautious approach.
The U.S. Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) don’t mince words about N-Butyryl chloride. This chemical counts as hazardous waste under federal law, so dumping it down the drain or tossing it in regular trash brings huge consequences. Crews on waste haulers won’t accept leaky or mislabeled containers. Most stories about environmental contamination start with someone cutting corners or not knowing the danger beneath that heavy, colorless liquid.
I’ve seen what happens when waste handlers come across unknown chemicals. Panic sets in—even seasoned workers take a step back because of the potential for toxic gas, fire, or even small explosions if someone gets careless. No one wants to be the person who turns a disposal job into a hospital visit or a news headline.
Disposal of N-Butyryl chloride stays in the hands of trained professionals for good reason. The first thing that happens is segregation—never mix it with random chemicals, especially water, alcohols, or amines. If this chemical remains pure, professionals often stabilize it by careful, controlled hydrolysis, but never in a regular sink. The process uses acid-resistant glassware and fume hoods, since strong vapors and heat follow. The product, mainly hydrochloric acid, still needs proper neutralization, so even the byproducts can’t go down the drain untreated.
Proper labeling and a well-kept chemical inventory matter as much as any fancy equipment. Hazardous waste firms provide guidelines for sealing the barrels, marking the contents, and logging every transfer. Dumping things out of impatience rarely ends well. In my own lab days, I’ve watched safety officers clamp down hard on anyone who skipped paperwork or failed to wear goggles and gloves. These steps save lives; they aren’t just bureaucratic checks.
So what stops more accidents? Investment in staff training places experienced eyes in the room. Instead of treating hazardous disposal as a routine, treat every batch as a big responsibility. Posting clear procedures and using safety drills can sharpen awareness. Building tighter relationships with certified chemical waste contractors also keeps surprises to a minimum. Many accidents start with a lack of communication between the people generating the waste and those taking it away.
Better engineer controls, like extra ventilation and spill kits, shrink the danger zone. Keeping emergency showers and eyewash stations clear and in working order also gives staff the best chance if mistakes happen. The big win comes from a culture where everyone—janitors to lab managers—recognize that chemical waste isn’t just another job to finish quickly.
N-Butyryl chloride reminds everyone in science and industry that cutting safety corners ends up hurting people, profits, and the environment. Cities expect organizations and individuals to handle waste with care, and regulators hold records tight for years. The message is loud and clear—do it right the first time, because chemicals never care about excuses, and neither will the law if something goes wrong.
| Names | |
| Preferred IUPAC name | Butanoyl chloride |
| Other names |
Butyryl chloride Butanoyl chloride Butyric acid chloride n-Butanoyl chloride |
| Pronunciation | /ɛnˌbjuːˈtɪrɪl ˈklɔːraɪd/ |
| Identifiers | |
| CAS Number | 111-64-8 |
| Beilstein Reference | 1718737 |
| ChEBI | CHEBI:51874 |
| ChEMBL | CHEMBL140269 |
| ChemSpider | 20215 |
| DrugBank | DB14112 |
| ECHA InfoCard | 100.003.755 |
| EC Number | 211-659-0 |
| Gmelin Reference | 8789 |
| KEGG | C14338 |
| MeSH | D002032 |
| PubChem CID | 10727 |
| RTECS number | BQ9625000 |
| UNII | UK8OB7KE4Z |
| UN number | 1760 |
| CompTox Dashboard (EPA) | DTXSID1064225 |
| Properties | |
| Chemical formula | C4H7ClO |
| Molar mass | 106.56 g/mol |
| Appearance | Colorless to light yellow liquid |
| Odor | Pungent |
| Density | 0.958 g/mL at 25 °C |
| Solubility in water | Reacts violently |
| log P | 1.88 |
| Vapor pressure | 14 mmHg (20°C) |
| Acidity (pKa) | 2.0 |
| Basicity (pKb) | 14.0 |
| Magnetic susceptibility (χ) | -7.39 × 10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.410 |
| Viscosity | 0.867 cP (20°C) |
| Dipole moment | 2.06 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 354.1 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -238.7 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -706.6 kJ·mol⁻¹ |
| Pharmacology | |
| ATC code | '' |
| Hazards | |
| GHS labelling | GHS02, GHS05, GHS06 |
| Pictograms | GHS02,GHS05,GHS06 |
| Signal word | Danger |
| Hazard statements | H226, H302, H314, H335 |
| Precautionary statements | P210, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P312, P330, P363, P370+P378, P405, P501 |
| NFPA 704 (fire diamond) | 3-2-2-W |
| Flash point | -20 °C |
| Autoignition temperature | 170 °C |
| Lethal dose or concentration | LD50 oral rat 640 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral-rat 1200 mg/kg |
| NIOSH | CAS7616 |
| PEL (Permissible) | PEL: 5 ppm |
| REL (Recommended) | 16°C |
| IDLH (Immediate danger) | IDLH: 5 ppm |
| Related compounds | |
| Related compounds |
Butyric acid Butyryl-CoA n-Butanol n-Butylamine Butyramide Isobutyryl chloride |
