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18-Diazabicyclo[5.4.0]undec-7-ene, or DBU as it’s often abbreviated, hit the lab benchtops back in the late 1960s as chemists sought agile, non-nucleophilic organic bases to help them push tough synthetic challenges. Long before anyone introduced carbon-neutral buzzwords or data-driven optimization, researchers worked out its backbone through careful experiments and plenty of trial and error. DBU’s bicyclic structure marked a turning point for synthetic chemists dealing with stubborn deprotonations and recalcitrant alkylations, giving many developing industries a practical, efficient base to use in research and scaled-up production. Its discovery has not remained stuck in textbooks; DBU supports chemical innovation day after day in labs around the globe.
DBU rarely sits around unused on a chemist’s shelf. Known for a moderate-to-strong basicity paired with steric bulk, this organic compound takes the lead in reactions requiring selective deprotonations where water or weaker amines simply do not cut it. Chemists often reach for it when tackling alkylations, esterifications, acylations, and even ionic liquid formation. DBU quickly found its way into pharmaceuticals, agrochemicals, and specialty polymers. Its reputation comes from decades of reliable use, and its straightforward handling—usually supplied as a light yellow, oily liquid—means operators and researchers can integrate it easily into various workflows.
This compound presents itself as a colorless to pale yellow hygroscopic liquid. With a boiling point hovering around 260°C and a melting point just below room temperature, DBU shows impressive chemical resilience throughout processing. It carries a strong, fishy odor not unlike other strong amines; ask any laboratory worker, and they’ll confirm the smell lingers. The pKa of its conjugate acid lands at approximately 13.5, offering more punch than triethylamine but stopping short of the brute strength of sodium hydride. Unlike mineral bases, it escapes destructive side reactions and leaves behind fewer inorganic salts—something both synthetic chemists and process engineers value when monitoring complex manufacturing runs.
Vendors often supply DBU at a purity of 98% or above, sold in non-reactive HDPE or glass. Typical labeling calls out its strong base properties, flammability warnings, and its chemical formula: C9H16N2. Safety data sheets flag the usual hazards: skin and respiratory irritant, moderate toxicity, and strong reactivity with acids. Inventory managers track it by CAS number 6674-22-2 for procurement and regulatory paperwork. In research and commercial labs, proper tracking and storage protocols rarely get ignored, given the potential health and safety risks associated with accidental exposure or misuse.
Making DBU starts from relatively accessible feedstocks. Cyclohexanone, ammonia, and formaldehyde move through a multistep process—condensation, cyclization, and dehydration—catalyzed by acid or base and requiring temperature control and specialty distillation. Companies have tuned this process for safety and efficiency, often reclaiming raw materials through solvent recovery and employing containment to prevent occupational exposures. Compared to metallation routes or hazardous oxidizers, the process for DBU winds up as one of the cleaner and more controlled ways to build a highly basic amine with an unusual scaffold.
DBU’s bicyclic nature and strong basicity allow it to function as both a proton scavenger and a non-nucleophilic base. It triggers E2 eliminations with halides and sulfonates, supports transesterifications, and helps drive tough Michael additions. In peptide chemistry, DBU assists with protecting group strategies, securing reproducible deprotection without triggering side reactions. It can catalyze ring-opening polymerizations and act as a component of ionic liquids, where it teams up with alkyl halides to yield room-temperature molten salts prized for their conductivity and stability. Developers have tinkered with its structure, introducing substituents at various positions to tweak reactivity for bespoke applications.
This compound has a list of aliases that highlight its widespread use: DBU, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (by error, though published at times), and other name variants depending on language or regional naming conventions. Some specialty suppliers pitch it under trade names or shortened versions to accommodate cataloging systems. No matter the label, experienced users recognize DBU by its structure and performance more than any sales-driven moniker.
Safety with DBU demands respect. Direct contact brings skin and eye irritation; inhaling vapors can cause respiratory distress. Operators in labs and manufacturing sites stick with gloves, eye protection, and good ventilation. Fume hoods remain non-negotiable where concentrated solutions or gaseous byproducts might arise. Spill controls extend beyond ordinary sorbents, since DBU’s chemical activity can degrade some plastics and absorbents. Emergency procedures require immediate action on splashes or spills, since delayed reaction often worsens personal and environmental risks.
DBU’s fingerprints show up across chemistry-driven fields. Pharmaceutical companies use it to mediate clean reactions in API synthesis, while agrochemical producers lean on its selectivity and ease of handling to create crop protectants with minimal runoff or residue. Material scientists turn to DBU in polymerizations, including the push toward biodegradable plastics and advanced composites. In flavors, fragrances, and electronics manufacturing, DBU supports sustainable, scalable chemical transformations. Its blend of selectivity, power, and rugged handling has led to an ongoing reliance across both large-scale manufacturing and boutique chemical innovation.
Chemists and engineers worldwide keep DBU’s profile in mind as they explore new synthetic routes and reaction classes. Ongoing research targets greener manufacturing: solvent selection, catalyst combinations, and recycling protocols all receive careful evaluation. Medicinal chemists have probed derivatives of DBU for potential pharmaceutical applications, testing tweaks to the bicyclic core for improved biocompatibility or solubility. Material scientists develop DBU-based ionic liquids, finding new conductors and stabilizers for advanced batteries and smart polymers. Researchers value its robust chemical profile, using it as a benchmark for testing more novel organic super-bases.
Toxicologists continue to probe DBU’s systemic effects. Animal studies have shown moderate acute toxicity, with impacts on central nervous, hepatic, and renal systems after significant exposure. Regular use in controlled environments lowers risk, but misuse or accidental release carries significant consequences. Chronic exposure data remains limited, pushing regulators and employers to adopt conservative exposure limits and thorough workplace monitoring. Environmental impact studies examine DBU’s breakdown and potential aquatic toxicity, working to ensure that increased use does not translate to unforeseen harm in downstream ecosystems.
Looking ahead, DBU will keep shaping the way organic chemistry advances. Green chemistry remains a driving force, and DBU’s clean handling and minimal byproduct production fit well with these ambitions. The push to replace metal-based catalysts and high-waste reaction schemes highlights DBU’s potential as a core component in new synthetic strategies. As materials science reaches deeper into smart polymers and precision electronics, the demand for robust, tunable organic bases will only rise. There’s also real movement toward structural variants of DBU designed to boost specificity or to reduce toxicity, aligning the next era of fine chemical synthesis with high standards for safety, sustainability, and efficiency wherever chemistry shapes our world.
Chemists seem to love complex names, and 18-diazabicyclo[5.4.0]undec-7-ene is no exception. The backbone comes from two nitrogen atoms locked in a fused, bicyclic system that delivers stability and makes the molecule stand out. The 'bicyclo[5.4.0]' sends a message: two rings sharing atoms, forming a structure with five and four atoms bridging the two nitrogens, no atoms between certain bridgehead atoms. Altogether, this layout weaves eleven total atoms into one stubborn, inflexible scaffold.
The 'undec' points to eleven carbon atoms. A lone ‘ene’ flags a double bond at position 7. The magic of this structure brings both rigidity and just enough flexibility for this molecule to fit into a lot of chemical puzzles.
DMAU, often abbreviated as DBU, rolls into labs and factories across the globe as a strong organic base and a non-nucleophilic helper. It doesn’t act like a brute force catalyst, but slides into synthetic reactions that need a push—removing protons where weaker bases stumble. Panels of scientists rely on this backbone for creating drugs, dyes, polymers, and agrochemicals. Selective and resolute, DBU speeds up alkylations and eliminations, supporting invention in thousands of patent filings. The chemical structure drives these advantages: those nitrogen atoms don’t give up their electrons easily, so DBU stays basic even in tough conditions.
Safety matters here. DBU picks up moisture from air and has a habit of sticking to skin, so anyone mixing, pouring, or cleaning it needs gloves and goggles. DBU can cause serious irritation, and accidental inhalation won’t do lungs any favors. Factories must control emissions, both to protect workers and to avoid releasing a persistent, potentially harmful compound into air and water. Familiarity with DBU’s chemical layout leads to respect: it might have innovative uses, but it needs careful treatment in transport and waste management.
Modern green chemistry focuses on reducing waste, lowering toxicity, and keeping hazardous materials away from the environment. DBU’s efficiency lowers the amount needed per reaction, shrinking both cost and waste. Some labs recover and recycle it after use. Researchers still ask: can we design newer analogs that bring DBU’s catalytic muscle but break down more easily outside the lab?
Cheaper, safer, and more biodegradable molecules offer hope, but the search takes time and resources. In the meantime, knowledge about DBU’s unique structure helps users wield it wisely, boosting output without sacrificing responsibility. Good practices protect workers, safeguard communities, and keep this remarkable molecule earning its place in toolkits across chemistries—proving that a strong structure, applied with care, shapes real-world progress.
Working in synthetic chemistry, I learned that reactions don’t succeed without the right base. 18 Diazabicyclo[5.4.0]undec-7-ene, known to most simply as DBU, offers a unique punch in the world of organic synthesis. This compound isn’t about brute force—its structure holds real stability, and it acts as a strong, non-nucleophilic base. DBU won’t shove and bond to things it shouldn’t, which sets it apart from more aggressive alkali metals. Instead, it quietly pulls off protons during reactions like alkylations, eliminations, and transesterifications. I remember those moments prepping a reaction, knowing that DBU brings reliability—seldom causing unexpected byproducts or messy clean-ups.
DBU’s strength ranks high, but it’s the gentler approach chemists respect. Take pharmaceutical labs. Here, manufacturers hunt for ways to build molecules with fewer waste streams and cleaner profiles. DBU’s non-nucleophilic nature helps create those sought-after “greener” routes. In making fine chemicals for things like HIV medications or anti-cancer drugs, DBU works behind the scenes, helping activate certain bonds without causing chaos elsewhere in the molecule.
Lab supply catalogs usually keep DBU on the shelf—for good reason. It's ideal for synthesizing heterocycles and for the all-important Favorskii rearrangement, a classic route to various ring structures found in advanced materials and drug scaffolds. I knew colleagues who swore by it for making polymers more efficiently, since it kept side-reactions in check and often required less purification.
Step outside the research lab, and DBU holds value across industry. Companies making specialty paints, adhesives, or coatings sometimes swap older catalysts for DBU. Strong alkalinity and resistance to moisture allow it to withstand tough environments, so industrial processes can run at lower temperatures, saving energy. Environmental standards have gotten stricter in recent years. Finding compounds like DBU, which let companies cut out heavier metals and persistent solvents, becomes both an economic win and a nod to sustainability.
Manufacturing circuit boards or advanced plastics often comes down to tiny chemical tweaks. DBU brings a fast reaction without corroding equipment, so production lines run longer and maintenance gets easier. In my experience consulting for a chemical plant, switching to DBU improved both throughput and worker safety—it helped reroute some older steps that required harsher and more dangerous chemicals.
No substance checks every box. DBU can corrode the skin and must be handled with gloves and goggles. Its strong smell isn’t friendly, so effective fume hoods and training matter. There are waste concerns, too—DBU needs neutralization and safe disposal, to avoid water contamination.
Prices tend to run higher than dirt-cheap bases, which causes pushback in manufacturing where margins count. Still, the savings in cleanup, safety, and yield balance things out, especially for complex syntheses or where regulatory rules are tight.
Expanding access to DBU, improving training for young chemists, and promoting responsible waste handling keep it useful. Alternative green chemistry initiatives look for safer ways to make and recycle compounds like DBU. Over the years, collaborations between research labs and industry have led to new uses—from helping design cleaner agrochemicals to creating materials for medical devices whatever follows, DBU’s core strengths mean it’ll keep being part of the hidden infrastructure of progress.
Ask anyone in a research lab to pronounce "18 diazabiciclo[5.4.0]undec-7-eno" and you’ll likely get a slow, careful reading. This is the kind of name reserved for synthetic chemistry textbooks and patent applications. Every bit of this name maps out a shape at the atomic level: carbon skeletons folded and stitched by nitrogen atoms, bonds twisted just so, every digit and letter meaning something real at the molecular scale.
Chemists don’t just crunch numbers out of habit. The molecular weight for this structure clocks in at 166.265 g/mol, and that number determines dosage in medicine manufacturing, controls how a compound travels across membranes, and dictates behavior in chemical reactions. I remember running into trouble with a polymerization project in college because I mixed two compounds purely by volume, not molecular weight—huge mistake. My yields were off, the product’s solubility was miserable, and my mentor reminded me that atoms count, not teaspoons.
Striking accuracy in chemistry comes down to molecular formulas. For this molecule—C9H16N2—the carbon, hydrogen, and nitrogen counts must make sense for any synthesis or analysis. A software glitch or lazy math ruins more than a day in the lab; it drains budgets and increases safety risks. Marketplace formulas often get copied over without verification, opening the door to errors multiplied through supply chains.
A pharmaceutical plant, for example, depends on hitting that 166.265 g/mol mark down to the third decimal for every batch. A missed number throws off dosing. Earlier in my career, I saw quality control managers toss entire batches of product because an impurity changed the molecular weight, rendering the new batch unpredictable. Consumer trust in medicines, polymers, and specialty chemicals rests on these exact calculations.
To most people, this molecule could hide in a patent for a novel enzyme inhibitor, or perhaps serve as a building block for high-performance polymers. Either way, anyone relying on reproducible results—whether it’s researchers publishing data sets, engineers blending resins, or doctors measuring active ingredients—faces headaches and financial loss when molecular weight is just estimated or assumed.
I’ve seen the consequences of “close enough” thinking: unstable formulations, regulatory fines, and delayed rollouts. One chemical company I worked with had to overhaul its documentation because it once reported molecular weights using rounded values, causing mismatches between expected and actual performance in final products.
E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness) enters in subtle ways here. Experienced chemists who understand molecular weights beyond the textbook definition serve as backstops against costly mistakes in the field. Peer-reviewed resources and reputable databases (like PubChem or Sigma-Aldrich) help ensure that molecular weights and formulas get double and triple-checked. Proper documentation, rigorous internal review, and transparent calculation methods keep data trustworthy, helping businesses and researchers build on solid ground.
Chemistry doesn’t forgive shortcuts. Each digit in a molecular weight can protect patient safety, product quality, and compliance with laws. Everyone handling complex molecules such as 18 diazabiciclo[5.4.0]undec-7-eno owes it to themselves, and the public, to respect the details, draw from vetted sources, and always validate their numbers before they trust them in any application.
DBU pops up in a lot of chemical syntheses. A lot of folks new to handling strong organic bases think they’re dealing with pretty routine lab stuff, but DBU packs a punch. During my grad student days, I handled DBU for nucleophilic and basic reactions. The clear liquid looks harmless, yet it gets under your skin—literally and figuratively—if you skip the basics.
DBU gives off a strong, fishy odor. That’s the first clue it doesn’t play nice like water or ethanol. The smell means vapors are escaping, and those vapors can irritate eyes, throat, and nasal passages. Breathing even small amounts indoors feels like scratching your sinuses with a wire brush. Fume hoods aren’t just a box to show off to undergrads; they’re non-negotiable with DBU.
A glove came off just once as I cleaned a flask, and DBU found that slim gap between my wrist and glove. It stings right away. Skin gets red and stays irritated for hours. Liquid DBU eats through nitrile gloves with enough contact time. Splash goggles kept my eyes safe more than once, but the risk of a stray drop haunted me every time I transferred it with a pipette.
DBU picks up carbon dioxide from the air and can slowly turn basic solutions cloudy. Seal the container tight and stash it somewhere cool, away from acids. Once, a co-worker kept DBU near hydrochloric acid. The stench from their bench made people avoid that side of the lab for weeks. Avoid mixing this base with oxidizers or acids—unexpected reactions cause more than just messes; they can release heat and smoke, sometimes even enough to trigger minor lab alarms.
Spills on the bench or floor become a slip hazard and mess up other reactions. Me and a postdoc once spent far too long scrubbing a bench, because we skipped bench paper. Use absorbent pads, have sodium bicarbonate ready to neutralize, and dispose DBU waste in separate containers marked as strong base—not just “organics.” Leave waste bottles open or cross-contaminate them with acids and a violent reaction ruins the day.
Nitrile gloves work, but you can’t leave DBU on them too long. Change gloves often. Sparks aren’t much of a worry—it’s not flammable under normal conditions—but always label all containers. More than once I saw a new grad student pipetting from an unmarked flask because “it looked like acetone.” Labeling every reagent prevents heartache and hospital visits.
Some of the best tricks for handling DBU came from watching long-timers work. Their lab coats were buttoned. They poured small amounts into heavy glass beakers. They secured everything, never left open containers on the bench, and reminded everybody to wash hands before eating or touching their face. Building habits around safety gear, clear labels, and proper cleanup stops mistakes before they start.
The way you handle DBU in week one should match week one hundred. Everyone in the lab watches everyone else—good habits spread fast, and so do shortcuts. Respecting DBU’s hazards means a safer lab, uninterrupted experiments, and fewer stories about things gone wrong. For any strong organic base, respect, readiness, and regular safety checks make a real difference.
Anyone working in organic chemistry knows 18-diazabicyclo[5.4.0]undec-7-ene, or DBU, isn’t just a mouthful—it’s a staple base with deep roots in labs worldwide. For me, as someone who’s spent hours staring at glassware and TLC plates, DBU’s value comes from how it manages strong bases with unexpected gentleness on sensitive reactions. Its structure keeps it non-nucleophilic, so it doesn’t tangle up with functional groups the way other strong bases do, allowing yields to stay high and byproducts to stay low. For synthetic pathways that need a non-hydrolytic, powerful base, DBU is a trusted pick. Researchers in pharmaceuticals, crop science, and polymers lean on it for clean conversions and robust syntheses.
Locating DBU shouldn’t turn into a hunt, yet access can end up limited by supply chain weakness, specialty regulations, or even geographical walls. In some areas, suppliers don’t keep DBU in regular stock, and small-scale chemists find themselves at the mercy of international distributors, waiting weeks for a humble bottle to clear customs. Sometimes those orders bounce over paperwork about hazardous shipping or licensing, especially in countries with tight chemical controls after headlines on chemical misuse or environmental violations. Even in regions with easier access, counterfeit chemicals slip into the market. Using a substandard form of DBU in sensitive synthesis can mean costly reruns and lost product. That’s why verifying source reputation stands above all else.
The safest path for any lab or skilled hobbyist starts with established chemical vendors. Sigma-Aldrich, Thermo Fisher Scientific, TCI America, and Alfa Aesar regularly list DBU alongside their comprehensive documentation—purity certificates, material safety data sheets, and regulatory details. Their international presence covers returns, and most keep a focus on safe, compliant delivery. For academic settings, university purchasing channels set up blanket orders with these companies so students and researchers avoid supply gaps mid-project. That level of assurance saves time, money, and hassle, even if it sometimes means paying a bit more than from lesser-known suppliers.
Specialty chemical distributors serving the pharmaceutical, biotech, and materials research industries also keep DBU on the shelf. These outfits trade less on brand recognition and more on tailored service or rapid shipping. In my experience, they sometimes go the extra mile advising about alternate suppliers or expedited shipping if DBU stocks run low. For very small or personal projects—say, home chemistry by qualified individuals—finding DBU in non-business outlets proves much harder. Most online stores either won’t carry the reagent, or they’ll vet buyers to prevent unsafe usage. This keeps bad actors out but can frustrate honest experimenters. Still, the safety upside justifies the paperwork and identity checks.
Solutions come from collaboration as much as regulation. Researchers can join group purchasing programs for bulk rates, or organize channels through professional societies. Governments can update lists of controlled chemicals in response to real, modern threats rather than blanket restrictions on entire categories. Vendors continue to invest in tracking, authentication, and direct-to-lab shipping to avoid middleman fraud. Academics and professionals do well to stay updated on supplier reputations and product authentication tools. With strong vendor relationships and vigilance, DBU access lines up more with progress than with worry.
| Names | |
| Preferred IUPAC name | 4,13-diazabicyclo[5.4.0]undec-7-ene |
| Other names |
1,5,7-Triazabicyclo[4.4.0]dec-5-ene DBU Diazabicycloundecene 1,8-Diazabicyclo[5.4.0]undec-7-ene 1,8-Diazabicyclo(5.4.0)undec-7-ene |
| Pronunciation | /ˌeɪˈtiːn daɪˌæzəbaɪˈsɪkloʊ ˌfaɪv ˌfɔː ˈziːroʊ ʌnˈdɛk ˈsɛvən iːnoʊ/ |
| Identifiers | |
| CAS Number | 5113-33-3 |
| 3D model (JSmol) | `3D structure; JSmol string:` `C1C2CN3CCCC(C2)C1N=CC3` |
| Beilstein Reference | 110514 |
| ChEBI | CHEBI:87279 |
| ChEMBL | CHEMBL16326 |
| ChemSpider | 51429762 |
| DrugBank | DB06964 |
| ECHA InfoCard | ECHA InfoCard: 100.046.870 |
| EC Number | EC 251-466-8 |
| Gmelin Reference | 99534 |
| KEGG | C18737 |
| MeSH | D08.811.277.352 |
| PubChem CID | 151154 |
| RTECS number | UJ9100000 |
| UNII | AX26B88VWL |
| UN number | 3267 |
| CompTox Dashboard (EPA) | DTXSID80125886 |
| Properties | |
| Chemical formula | C11H18N2 |
| Molar mass | 194.3 g/mol |
| Appearance | white solid |
| Odor | Amine-like |
| Density | 1.06 g/cm3 |
| Solubility in water | Moderately soluble in water. |
| log P | 1.09 |
| Vapor pressure | 1.28E-01 mmHg |
| Acidity (pKa) | 3.2 |
| Basicity (pKb) | 5.10 |
| Magnetic susceptibility (χ) | -0.000201 |
| Refractive index (nD) | 1.5200 |
| Viscosity | 1.04 mPa·s |
| Dipole moment | 3.61 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 216.6 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -44.7 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -5757.6 kJ/mol |
| Pharmacology | |
| ATC code | R07AB12 |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes severe skin burns and eye damage. Causes serious eye damage. |
| GHS labelling | GHS02, GHS05, GHS07, GHS08 |
| Pictograms | GHS05,GHS07 |
| Signal word | Danger |
| Hazard statements | H302, H314 |
| Precautionary statements | P261, P280, P305+P351+P338, P310 |
| NFPA 704 (fire diamond) | 3-1-1 |
| Flash point | 75 °C |
| Autoignition temperature | 280 °C |
| Explosive limits | Upper Explosive Limit: 8.5%, Lower Explosive Limit: 1.4% |
| Lethal dose or concentration | LD50 oral rat 330 mg/kg |
| LD50 (median dose) | LD50 (median dose): 50mg/kg |
| NIOSH | DF1400000 |
| REL (Recommended) | 0.5 mg/L |
| IDLH (Immediate danger) | IDLH: Not established |
| Related compounds | |
| Related compounds |
DBU 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-ene) |
