1-Chlorobutane: Commentary and Insights from Lab Bench to Industry Floor
Historical Development
Early chemists searching for reliable alkyl halides landed on 1-chlorobutane, not through luck, but because of its manageable straight-chain structure and reactivity. Over the 19th and 20th centuries, its popularity grew in laboratories and factories exploring organochlorine synthesis, solvents, and stepwise hydrocarbon modification. It found its way into research papers and industrial catalogs because workers discovered its balance between volatility and stability made for controlled experiments without sudden surprises. Before modern specialty solvents hit the shelves, 1-chlorobutane offered practicality in developing new reactions and training chemists on handling halogenated compounds.
Product Overview
1-Chlorobutane, or n-butyl chloride, shows up as a clear, colorless liquid carrying a faint, sharp odor—easy to spot on a busy bench. It dissolves in organic solvents far better than in water, helping as both a reactant and blending agent for chemical transformations. In my own lab days, I found it essential for organic synthesis, acting as the backbone for building complex molecules. Considering its straightforward alkyl chain, industry leans on this compound for applications needing a predictable chlorinated starting material. Chemical manufacturers count on it because, unlike heavily substituted chlorides, it keeps byproducts simple during downstream processing.
Physical & Chemical Properties
1-Chlorobutane’s boiling point sits near 78°C, and it freezes at -123°C—a trait handy for reactions requiring broad temperature control. It mixes well with ether and alcohols. Weighing in with a molecular weight of 92.57 g/mol and a density of 0.89 g/cm³ at 20°C, it makes accurate dosing and industrial-scale transfers easy. It stays stable under normal lab conditions, but direct sunlight or open flames can trigger decomposition, so storage in amber glass or proper drums matters. The molecule reacts in classic nucleophilic substitution and elimination reactions—bread and butter moves in organic chemistry—helping researchers and producers dial up complexity from such a basic scaffold.
Technical Specifications & Labeling
Bottles of 1-chlorobutane from reputable suppliers arrive labeled with clear hazard warnings, flammability details, UN number (1127), and purity data—typically above 99%. GHS pictograms, hazard statements, and safety instructions stand out on packaging, drawing attention to potential risks. Quality labs track lot numbers for traceability, making it easier to investigate any downstream quality issues. Regulatory compliance—both local and international—demands transparent labeling and documentation from raw material to finished pack.
Preparation Method
Classical methods favor reactions between 1-butanol and thionyl chloride, phosphorus trichloride, or hydrogen chloride gas. Out of all routes, thionyl chloride sticks out for efficiency. Reacting 1-butanol with SOCl₂ in the presence of a catalyst creates a smooth transformation with few side-products. I've run this conversion under fume hoods, and proper ventilation remains vital since SO₂ and HCl fumes sting and damage mucous membranes. Producers optimize parameters like temperature, reagent ratios, and mixing intensity to scale up this reaction, keeping unwanted byproducts at bay and yields high. Crack open historical texts or recent patents, and tweaks abound: acid catalysts, batch versus continuous systems, and solvent choices play considerable roles in scaling for bulk production while keeping impurity profiles predictable.
Chemical Reactions & Modifications
On the reaction front, 1-chlorobutane transforms easily. Grignard reagent preparation pops up in textbooks, and this molecule supplies a classic alkyl halide starting point. Chemists thrive on its role in nucleophilic substitution (SN2), where nucleophiles swap out the chloride, building longer or branched alkyl chains. I've made alkylated amines and ethers, leaning on its straightforward reactivity. Elimination reactions generate 1-butene, useful for downstream alkene functionalization. Under strong conditions, the molecule resists rearrangement, holding that straight C₄ chain—a benefit for those chasing unbranched derivatives. It's a key player in synthesizing agrochemicals, pharmaceuticals, and specialty polymers, bridging elemental feedstocks and finished products.
Synonyms & Product Names
Across safety data sheets and supply catalogs, you’ll see 1-chlorobutane listed as n-butyl chloride, butyl chloride, or chlorobutane. Some chemical trackers flip “1-chlorobutane” and “butyl chloride,” but the structure—four-carbon straight alkyl chain bearing chloride at one end—keeps identification accurate. Workers in industrial warehouses and analytical labs scan for these common names, reducing mix-ups and accidental substitutions.
Safety & Operational Standards
Handling 1-chlorobutane challenges both novice and seasoned workers. Even brief exposure can irritate skin, eyes, and the upper respiratory tract. Flammable vapors linger close to the floor, snaking toward ignition sources unless labs run proper ventilation. Splash goggles, gloves, and lab coats become daily ritual. Spills demand speedy cleanup using inert absorbents, then thorough disposal in line with hazardous waste laws. Any accidental inhalation or skin contact leads to a race for the eyewash or safety shower. Trained personnel oversee bulk operations, and even small-scale chemists run reactions within vented hoods. Monitoring for chronic exposure stands as a best practice because long-term health impacts surface quietly, making prevention and exposure logs essential on both sides of the Atlantic.
Application Area
Industrial demand for 1-chlorobutane winds through diverse sectors. As a raw material for manufacturing pharmaceuticals, it shows up in active ingredient synthesis, or in building blocks that get transformed later. Agrochemical developers rely on it for making herbicides and pesticides—stepwise reactions benefit from its clean substitution chemistry. Solvent manufacturers blend it into products meant for fats, oils, and alkaloid extraction. PVC resins and specialty rubber processes sometimes draw from its supply. At the bench scale, research teams craft new compounds through substitution, elimination, and coupling reactions. Manufacturers often blend real-world experience with digital process controls to optimize yields and lower environmental footprints.
Research & Development
Chemists exploring new reaction pathways rely on 1-chlorobutane for its straightforward structure and clear outcomes in SN2 and elimination systems. It’s a foundation for testing new catalysts and greener synthesis conditions since unwanted byproducts remain easy to detect. Graduate students and process engineers use it for proof-of-concept work, validating mechanisms and scaling up transformations before tackling more expensive or sensitive substrates. It serves as a control or benchmark in high-throughput screening runs aimed at mapping catalytic behavior, kinetic trends, or byproduct profiles. In academic circles, hundreds of publications use 1-chlorobutane as a starting point for synthetic method development or novel bioactive molecule construction.
Toxicity Research
Long-term studies point out the risks of chronic exposure. Animal data highlight nervous system effects after repeated inhalation, and regulatory bodies flag its flammability and acute toxicity as higher than that of longer-chain relatives. Reports document both reversible and irreversible changes in pulmonary function, especially among workers exposed to airborne chlorinated hydrocarbons in unventilated spaces. Absorption through skin or ingestion, even in small amounts, generates systemic symptoms—headache, nausea, central nervous system depression. Working with this compound, I’ve seen researchers log every incident and always double up on PPE during solvent transfers. Big producers run regular training and toxicological screenings to safeguard employees and communities near production sites.
Future Prospects
Market demand for 1-chlorobutane tracks global growth in specialty chemical production. Sustainability pushes steer R&D toward greener chlorination methods, safer downstream processing, and systems producing fewer emissions. Digital monitoring and real-time analytical controls promise tighter tolerances and less waste. There’s momentum in shifting to renewable feedstocks, with some labs working on biobased alcohols as alternatives to petro-derived sources, so future butyl chloride may come with smaller carbon footprints. Regulatory scrutiny will likely tighten, with stricter limits on workplace exposure and effluent standards nudging manufacturers toward closed-loop or alternative chemistries. Still, demand from pharmaceutical, agricultural, and specialty material sectors propels ongoing investments in technology, safety, and process optimization. Every trend pushes both compliance and innovation—not just to tick boxes, but to keep people, products, and the planet safer for the long haul.
What Makes 1-Chlorobutane Stand Out in Industry?
1-Chlorobutane shows up in more places than most people think. In labs and factories, this clear liquid is like a gateway for more complex molecules. It acts as a workhorse in the organic chemistry toolbox, especially when people build longer hydrocarbon chains. Folks in chemical manufacturing want reliable and predictable reactions, and 1-Chlorobutane delivers that. Its core role comes in as an “alkylating agent”—in plain terms, it joins with other stuff to kick off a chemical change. That’s handy for anyone making pharmaceuticals, rubber additives, or certain herbicides. The pharmaceutical angle matters a whole lot to people waiting on better medicines. Builders of these drugs use simple chemicals like 1-Chlorobutane as stepping stones to create compounds that actually help patients.
Household Chemistry and Everyday Life
My own run-ins with 1-Chlorobutane happened in the lab back in college. We used it to synthesize other chemicals, transforming one clear liquid into another form entirely. This process crops up outside the classroom too. Companies that manufacture flavors for food or scents for perfumes might use it in early stages of production. While it isn’t the stuff you want to spill on your hands, it’s crucial behind the scenes for a host of finished products that end up on shelves.
Basic Science, Real-World Consequences
The technical side links to everyday issues. Some plastics, adhesives, and specialty rubbers wouldn’t exist—or would cost a lot more—without starting materials like 1-Chlorobutane. It’s not always top of mind, but it matters for those price tags in the hardware aisle or the durability of everyday items we count on. On top of that, researchers turn to this chemical for making substances that remove sulfur from gasoline. Cleaner fuel leaves the air less polluted, so the effects ripple out into public health and environmental quality. I’ve seen how even small tweaks in fuel formulation can change how our cities smell or how lungs feel during allergy season. That’s where these foundational chemicals cross from abstract science to things you can feel in your daily routine.
Environmental and Safety Considerations
Any chemical worth using in bulk deserves a careful look at risk. 1-Chlorobutane can irritate skin and eyes if mishandled. It can hurt water quality if it leaks into rivers or lakes. Chemical workers know this story too well—hospitals sometimes see burns or breathing trouble from accidents in plants that use chemicals like this. Modern guidelines recommend working in well-ventilated spaces, wearing gloves, and tracking disposal. After a couple close calls in the lab, I learned firsthand that a splash in the wrong place becomes everyone’s worry.
Moving Toward Safer Use
Industry experts and safety agencies push for better handling practices every year. Digital tracking and stronger containers cut down on spills. New green chemistry methods aim to swap out substances like 1-Chlorobutane for safer options if possible. Teaching responsible use in the classroom sets a foundation. Changing old habits in mature industries stays tough, but steady steps keep reducing risks over time. Companies and regulators now share more information, making it easier to learn from mistakes and keep workers—and neighborhoods—out of harm’s way.
Understanding the Risks
Working in a lab, I’ve come across 1-Chlorobutane on a handful of occasions, mostly as an intermediate for synthesis projects. It looks harmless — a clear liquid, mild chemical smell — but the dangers sit beneath the surface. This is not just another bottle on the shelf. 1-Chlorobutane can irritate eyes, skin, and lungs. It will catch fire without much encouragement. The chemical also releases vapors that build up in confined spaces. While not as notorious as some solvents, it doesn’t take much for exposure limits to creep up past safe levels. The CDC lists short-term exposure limits, but real-world experience says to take every warning seriously.
Personal Protective Equipment
Lab coats only go so far. Nitrile gloves fit tight and keep 1-Chlorobutane off your skin, but you can’t skip the safety glasses or goggles. Splashing it into your eyes leaves a sting you won’t soon forget. Gloves might seem like a hassle if you work fast, but one slip turns a shortcut into a trip to the eye wash. I always keep a face shield nearby if there’s any chance liquid will spray.
Ventilation and Safe Handling
Good airflow makes a huge difference. Every chemist has cracked a bottle open only to get a whiff — that's a warning sign. Fume hoods block most of the undesired exposure. I keep all reactions and transfers under the hood, avoiding even brief moments out in the open. Bottling and pouring goes into a tray to catch drips. People forget the little things, like checking the hood sash isn’t too high for air flow, or capping bottles tight as soon as you’re done, but these habits mark the difference between a close call and real harm.
Spill and Fire Response
Few things spike your heart rate like a spill in a shared lab space. For 1-Chlorobutane, a small puddle on the bench means don’t panic, but don’t wait. I reach for absorbent pads made for chemicals, not regular paper towels, and bag the waste right away. This stuff heads straight to the hazardous collection bin. Larger spills or fire risk? That’s a pull-the-alarm moment. Don’t use just any extinguisher — dry chemical powder or carbon dioxide types work best. Foam doesn’t cut through chlorinated solvent fires. If you’re not trained, clear out and let safety crews take over.
Storage and Waste
Chemical storage tends to slip down the list of worries till something leaks or cracks. 1-Chlorobutane belongs in a flammable liquids cabinet, locked up and segregated from oxidizers. Never store it near open flames or use hotplates without proper shields. Every bottle needs a label, no permanent marker shortcuts. For waste, it’s not a drain disposal candidate. City and campus rules demand proper hazardous waste procedures, from labeled containers to regular pickups. I’ve seen labs shut down over a single mishandled waste bottle.
Health Monitoring and Training
Some chemicals send out rough warnings; with 1-Chlorobutane, symptoms can be sneaky — dizziness, headaches. Short health surveys and basic on-the-job training save trouble. If someone complains about headaches or sore throats when working with solvents, it’s time to step back and check exposure controls. The best labs run annual fit tests for respirators and keep protocols visible.
Better Habits, Fewer Accidents
Safety grows from mindset, not checklists. In every lab, the people who pay attention — double-checking labels, asking for help, sharing close calls — keep the work environment safer for everyone. Transparency trumps bravado. With experience, handling 1-Chlorobutane gets routine, but shortcuts are just another way of rolling the dice.
Understanding 1-Chlorobutane at the Core
Every student who has sat through an organic chemistry class probably remembers naming conventions. But the real magic happens when you break down a name like 1-chlorobutane. It sounds like a mouthful, yet it tells a simple story. The chemical formula for 1-chlorobutane is C4H9Cl. Count up four carbons, a chain with single bonds, stack it with nine hydrogens and stick a chlorine atom on the end—that's what we're looking at.
Those four carbons form a straight line. The "1" means chlorine takes the spot at the very first carbon. Think about butane, the lighter fluid and regular at-home chemistry staple—swap a hydrogen on the end for a chlorine atom and you get 1-chlorobutane. The change looks small, yet swapping an atom gives this molecule a completely different personality. It goes from a simple aliphatic hydrocarbon to a reactive alkyl halide, ready for all sorts of chemical transformations. This matters in everything from solvents used in labs to making other chemicals that we end up using in medicine or materials.
Why the Chemical Formula Matters
A formula like C4H9Cl may look simple, but getting it right builds trust. Accurate formulas keep the entire chemical supply chain safe. In school, I once used a mislabeled compound and ruined an entire afternoon of lab work. Out in the real world, a wrong label or sloppy formula can lead to bigger problems: wasted resources, dangerous reactions, or product recalls. Chemical companies and research labs depend on reliable information for safety and efficiency.
Regulation backs this up. The European Union's REACH regulation, and U.S. standards from the EPA and OSHA, all demand exact reporting of chemicals handed off or sold. One slip-up and you risk fines or more serious safety problems. Proper communication around formulas matters for everyone down the line, from transporters to end users.
Science at Work: Synthesis and Transformations
1-chlorobutane acts as more than just a sample in a classroom. In industry, it forms a handy starting point for building things like pharmaceuticals, agrochemicals, or specialty solvents. Chemists can use it in nucleophilic substitution reactions to swap out that chlorine for something else. My first real exposure to hands-on synthetic chemistry started with reactions like these—watching how one swapped atom could open the door to a new compound altogether. Small changes at the molecular level lead to major breakthroughs in new products.
Risks and Practicality: Beyond the Formula
Every chemical brings some baggage. With 1-chlorobutane, safety matters. It's flammable, and its vapors might irritate your eyes or skin. In my old undergraduate lab, one careless spill cleared the room in minutes. Anyone who handles chemicals needs clear labels, safety data sheets, and the right equipment.
Making Chemistry More Accessible
Communicating chemical information calls for more than jargon or fancy names. In a world worried about fake products and accidental misuse, plain talk about structure, formula, and hazards helps everyone make smarter, safer choices. Building chemical literacy in this straightforward way may not turn everyone into a chemist, but it will give folks the right tools to ask questions and look out for themselves and their colleagues.
Why 1-Chlorobutane Needs Special Care
Anyone with hands-on lab experience knows certain chemicals demand closer attention. 1-Chlorobutane fits that description. Colorless as it might look, this liquid can quickly turn into a fire hazard or health risk if handled carelessly. I’ve seen mistakes in storage—twisted caps, loose lids, and heat creeping in under sunny windows—lead to headaches, skin burns, and strong odors that linger in the air far too long.
OSHA calls this substance both flammable and potentially harmful if inhaled, referencing studies that show moderate irritation affects the skin, eyes, and respiratory system. Safety protocols come from real events, not imagination. Two years ago, a misplaced bottle near a water heater forced our lab to evacuate after the vapors triggered a fire alarm. Nobody wants to repeat that.
The Right Place: Away From Heat and Sunlight
Metal cabinets marked “Flammables Only” serve a real function. They block heat from electrical equipment and sunlight, both of which escalate risks fast. 1-Chlorobutane catches fire at temperatures as low as 13°C. Even a lukewarm shelf might push it closer to trouble. A dim, well-ventilated corner in a flammable safety cabinet gives this chemical the respect it deserves.
Friends in industrial settings swear by storing it in cool rooms, often below 25°C, with constant thermal monitoring. Storage experts back that up; one NIOSH guide points to lower temps slowing down evaporation and reducing explosion risks. Insulation matters, but so does dry air: any water humidity in the storage environment tends to corrode caps and labels, which can lead to drips and leaky bottles. I’ve seen cardboard boxes go soft and disintegrate after a week in a humid storeroom.
What the Label Doesn’t Say
Labels do their best, listing warnings and handling guidelines, but they never show the damage a simple mishap can cause. In my student days, we stacked incompatible bottles too close together. 1-Chlorobutane and strong oxidizers like bleach or nitric acid don’t just argue—they explode. The CDC’s Chemical Safety Card bluntly says: keep 1-Chlorobutane separate from oxidizers and acids. Treat these divisions seriously. Use plastic secondary containment trays and never let vapors mix with air in confined places. More than one college lab has learned this lesson the hard way, with broken glass and chemical burns as reminders.
Practical Protection: PPE, Spill Kits, and Training
Tools and training act as silent guardians. Storing 1-Chlorobutane means never relying on memory. PPE—goggles, gloves, face shields—sits close to the storage space. Spill kits, including absorbent pads and neutralizing agents, should rest within arm’s reach. I push for regular walk-throughs and drills with every new coworker. Emergencies demand speed; no one should fumble for a proper mask in the middle of a spill.
A Matter of Responsibility
Long-term safety comes from a culture, not just policies. I see successful teams review chemical inventories monthly. Expired or partially filled bottles leave labs, not waiting for an accident. Updated training and clear signage stand out as proof that people—not just rules—keep 1-Chlorobutane from causing harm. This approach builds trust and, by extension, keeps everyone safer in spaces where even a small lapse can invite disaster.
Looking at the Basics
1-Chlorobutane stands out as a simple organic compound, hiding out in clear or colorless liquid form. A lot of folks know it by its traditional bottle-label kind of smell—sharp, almost sweet, but definitely noticeable if you’ve spent time around chemicals in a lab. Its molecular formula, C4H9Cl, gives it away as a straight-chain butyl group with a chlorine atom replacing one hydrogen at the end.
How it Handles Heat and Cold
Any chemical user will tell you to keep an eye on boiling and melting points. 1-Chlorobutane boils at about 78°C (173°F). That’s not too far above water’s boiling point, but it evaporates a lot faster if you leave the cap open. Melting comes in around -123°C (-189°F), so it refuses to freeze up unless you take it to some serious subzero temperatures. Because of its fairly low boiling point, storing it away from heat sources makes sense.
Mixing It Up in the Lab
Solubility causes headaches for some folks. 1-Chlorobutane avoids water and simply floats on top. Its density clocks in at about 0.89 g/cm³. So, drop a bit in water and it won’t sink. Instead, you’ll watch a slick form on the surface. Start adding organic solvents, like diethyl ether or alcohol, and it blends easily. This kind of behavior shapes the ways people use it in synthesis or as a solvent itself.
Density and Flammability
I remember opening a fresh bottle one day, and right away, its lightness caught my eye. Pour some out, and you'll see it spreads quickly, thanks to its relatively low density. Most hydrocarbon-based organics show the same kinds of tricks. Safety-conscious labs often post up the flashpoint, and here it’s a real concern. With a flashpoint around 6°C (43°F), open flames or sparks spell trouble. Ventilation becomes key; everyone in the lab learns that lesson early—never ignore those faint chemical scents wafting through the air.
Staying Tough or Breaking Down
Some chemicals cling to stability, but 1-chlorobutane won’t fight back too much if exposed to direct sunlight or if stored in old, corroded containers. If left unattended, it doesn’t just lose its punch, it may even start reacting with strong bases, acids, or certain metals. Good practice means storing it in dark, tightly sealed bottles, far from oxidizers or alkali metals. These aren’t just textbook precautions—plenty of labs have stories about wasteful spills and unnecessary exposure from bad storage.
Real-World Handling and Impact
Working with 1-chlorobutane means respecting it, not fearing it. The liquid absorbs easily through the skin. Fumes start to irritate after a short while, reminding anyone nearby to use gloves and work with proper ventilation. Forgetting eye protection can be a quick ticket to red, irritated eyes for the rest of the day. Being mindful of its physical properties—its volatility, flammability, and tendency to react with certain materials—does more than prevent waste. It cuts down the chance of accidents, keeps air quality safe, and makes sure none of the valuable material gets lost to unnecessary spills or evaporation.
Better Storage and Safety Practices
Simple steps lead to safer labs—labeling containers clearly, storing away from incompatible chemicals, and keeping spills in check with absorbents. Training new lab workers in the real risks, not just what’s printed on a sheet, builds respect for these kinds of chemicals. With its unique combination of low boiling point, stubborn insolubility in water, flammable vapors, and ease of skin absorption, 1-chlorobutane stands as a clear example of why hands-on knowledge beats reading data sheets alone.
| Names | |
| Preferred IUPAC name | 1-Chlorobutane |
| Other names |
1-Chlorbutan
n-Butyl chloride Chlorobutane n-Butane chloride |
| Pronunciation | /waɪ ˈklɔːrəʊ.bjuː.teɪn/ |
| Identifiers | |
| CAS Number | 109-69-3 |
| Beilstein Reference | 1209240 |
| ChEBI | CHEBI:35720 |
| ChEMBL | CHEMBL13378 |
| ChemSpider | 14117 |
| DrugBank | DB01998 |
| ECHA InfoCard | 100.003.267 |
| EC Number | 203-695-1 |
| Gmelin Reference | 7865 |
| KEGG | C01559 |
| MeSH | D002834 |
| PubChem CID | 8008 |
| RTECS number | EJ5950000 |
| UNII | T3C89M417N |
| UN number | UN1127 |
| Properties | |
| Chemical formula | C4H9Cl |
| Molar mass | 92.57 g/mol |
| Appearance | Colorless liquid |
| Odor | sweet odor |
| Density | 0.886 g/mL at 25 °C |
| Solubility in water | 10.3 mg/mL (20 °C) |
| log P | 1.92 |
| Vapor pressure | 11.8 mmHg (20°C) |
| Acidity (pKa) | 15.0 |
| Basicity (pKb) | Basicity (pKb): 15.49 |
| Magnetic susceptibility (χ) | -52.4e-6 cm³/mol |
| Refractive index (nD) | 1.399 |
| Viscosity | 0.682 cP (at 20 °C) |
| Dipole moment | 2.29 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 216.1 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | –152.2 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -2857 kJ/mol |
| Hazards | |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS02, GHS07 |
| Signal word | Warning |
| Hazard statements | H225, H315, H319, H335 |
| Precautionary statements | P210, P261, P301+P312, P331, P303+P361+P353, P304+P340, P305+P351+P338, P312 |
| NFPA 704 (fire diamond) | 1-2-0 |
| Flash point | -6 °C |
| Autoignition temperature | 245 °C |
| Explosive limits | Upper explosive limit: 10.6% (V), Lower explosive limit: 1.4% (V) |
| Lethal dose or concentration | Lethal dose or concentration: LD50 oral rat 2,680 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral rat LD50 = 3200 mg/kg |
| NIOSH | CN8400000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) of 1-Chlorobutane: 100 ppm (350 mg/m³) |
| REL (Recommended) | 100 mg/m³ |
| IDLH (Immediate danger) | 800 ppm |
| Related compounds | |
| Related compounds |
Butane
2-Chlorobutane 1-Bromobutane 1-Iodobutane 1-Fluorobutane |
