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3,5-Dinitrobenzoic acid first showed up in the chemical literature over a century ago. Early synthetic chemists eyed this compound for the challenges it posed and the windows it opened to understanding aromatic substitution patterns. Its preparation, marked by those signature bright-yellow crystals, became a landmark for students of both organic chemistry and the burgeoning field of physical chemistry. Over time, the compound entered textbooks because it told a story about how functional groups interact on an aromatic ring, especially when strong electron-withdrawing nitro groups gather around a carboxylic acid. These early investigations set important benchmarks for methods that built on selective nitration processes, which grew into the robust processes seen today. That legacy means experienced chemists immediately recognize the compound as more than a relic; its ongoing relevance continues in a range of sophisticated laboratory practices.
Today, 3,5-dinitrobenzoic acid appears on chemical inventories and in catalogues for lab supplies in both teaching and research settings. The compound stands apart as a useful tool in modern analytical and synthetic work, especially in the hands of those focusing on compound identification or the modification of aromatic systems. Some might see it as another reagent on a shelf, but its uses stretch much further. In method development, its well-known melting point and easy recognition by color and TLC behavior lend it frequent use as a standard in basic labs.
This substance crystallizes into sharp, lemon-yellow needles, with a melting point that hovers near 205°C, depending on purity and procedural nuances. Its poor solubility in cold water presents both a challenge and an advantage; recrystallizing from hot water or alcohol lets chemists achieve a purity level suitable for many analytical and preparative goals. The strong electron-withdrawing nitro groups parked at the 3 and 5 positions impact both physical features and chemical reactivity: they pull electron density away from the aromatic ring and carboxyl group, strengthening acidity and shifting typical reaction profiles compared to simpler benzoic acids. In practice, one sees this in titration behavior—it stands out in acid-base analyses due to its lower pKa, creating a reference point for new chemists learning the ropes.
In the lab, this compound usually shows up labeled with key identifiers, including CAS number and molecular formula (C7H4N2O6), which, even for a seasoned chemist, saves time when sorting through a cluttered stockroom. The bright yellow hue warns of nitro content, sometimes paired with hazard pictograms highlighting toxicity or environmental risk. Detailed labels matter here—not just for compliance, but for protecting everyone working in shared spaces. Large-scale syntheses demand even clearer technical details, with batch purity, trace contaminant reports, and handling requirements. Some companies add QR codes more recently, letting people check detailed documentation from a phone instead of risking errors near a workbench.
Standard preparation relies on the double nitration of benzoic acid—a process that starts with the slow, careful addition of nitric acid and sulfuric acid to benzoic acid under chilling, then moves through a control of temperature and stirring speed that often feels as much art as science. Plenty of chemistry students have scorched batches or ended up with unwanted isomers by rushing this reaction. Experienced hands know the purity of reagents, rate of acid addition, and timing decide if those yellow needles come out of solution or if the product ends up in the waste drum. Lab-scale preparations run into the safety hazards of hot nitric acid, spattering, and nitrous fumes, so old-school fume hoods retain their place in any practical synthesis.
The reactivity of 3,5-dinitrobenzoic acid sets it up for more than shelf storage. The nitro groups make the aromatic ring less nucleophilic, blocking many common electrophilic aromatic substitution reactions. This trait means attempted brominations or Friedel-Crafts reactions stall out, teaching new chemists a valuable lesson about resonance and reactivity. In contrast, the compound acts as a good partner in reduction or nucleophilic aromatic substitution reactions, which find application in the building of more complex molecules. Derivatization with alcohols or amines switches the carboxylic function for esters or amides, routes that help in analytical chemistry to distinguish stereochemistry or to sequence stages of multistep syntheses.
Depending on where you look, 3,5-dinitrobenzoic acid turns up as m-dinitrobenzoic acid, DNBA, or by names like Benzene-1,3-dicarboxylic acid, 5-nitro-, but those working in labs tend to stick with the basic synonym for clarity’s sake. This sometimes causes confusion if one shifts between commercial catalogs from the US, Europe, or Asia. A search for DNBA might miss a listing that’s tucked under the full compound name, so knowing your synonyms saves more than just time—it keeps projects moving.
Nitro-containing compounds set off bells for anyone who’s handled them in quantity. 3,5-Dinitrobenzoic acid comes with toxicity risks—skin sensitization, irritation to eyes and mucous membranes, and noxious fumes on heating or decomposition. Handling it means pulling on gloves, keeping goggles on, and staying under strong ventilation, even on routine days. Long hours in the lab make it easy to slip on safety, but standards exist thanks to the lessons learned from past accidents, big and small. Waste goes carefully into dedicated containers, never with general organic refuse, because nitroaromatics don’t mix well with reducing agents, strong bases, or heat. Regulatory agencies like OSHA and EPA add another layer with specific rules for bulk handling and disposal, which sit alongside professional codes in chemical research.
3,5-Dinitrobenzoic acid finds its main home as a derivatizing agent in analytical chemistry, where it reacts with alcohols and phenols to form identifiable esters and amides—a must in structural elucidation or purity checks. In teaching labs across the world, it’s almost a rite of passage for students to make a 3,5-dinitrobenzoate derivative of an unknown compound, then match melting points to published tables, cracking the code of substance identity. Specialties crop up in pharmaceutical research, where modifying the parent molecule sheds light on how drugs interact with different functional groups, giving medicinal chemists tools to probe structure-activity relationships. The strong acid function and nitro substituents also attract material scientists wanting electron-deficient aromatic rings for work in charge-transfer complexes, which show up in everything from analytical sensors to early organic electronic projects.
Teams in pharma, chemical process design, and material science have all poked and prodded at 3,5-dinitrobenzoic acid over the years, using it as both a building block and a probe for mechanistic study. Detailed kinetic studies and computational models rely on its predictable behavior, and its simple but revealing structure often serves as a baseline for developing new substituted benzoic acid derivatives. Instrument companies use it for calibrating melting point apparatus or fine-tuning chromatography systems, since its retention time and UV absorbance are well-known. In structural biology, the compound helps by acting as a tag or a modifier in protein chemistry, where it can help isolate or characterize functional groups on larger biomolecules. The more closely chemists study electron-withdrawing effects in aromatic systems, the more this compound keeps showing up as a core reference in both published work and patent literature.
Workers in toxicology have flagged 3,5-dinitrobenzoic acid for both acute and chronic effects. Animal models and cell lines point to cellular disruption, oxidative stress, and enzyme inhibition tied to the nitroaromatic structure. Case studies have linked exposure to skin rashes and respiratory irritation; regulatory flags warn about groundwater contamination if lab waste gets mishandled. Some research suggests that environmental persistence of nitrobenzoic acids might pose risks to aquatic life, with breakdown products traveling farther than one might expect through soil or sediment. My own colleagues remind me that proper micro-scale protocols and engineering controls matter, not just in high-volume industrial settings but also in university teaching labs, where the temptation runs high to shortcut proper disposal. Understanding the mechanisms of toxicity doesn’t only come from textbook reading—every lab accident or near-miss adds another reason to handle with real care.
Innovation in green chemistry keeps re-framing the future for nitrobenzoic acids like this one. Safer nitration techniques, waste minimization strategies, and biodegradable alternatives create a push and pull for researchers balancing performance with responsibility. Those in pharma and materials science still see value in its ability to define reaction pathways and supply new intermediates. Analytical chemists keep finding ways to use its distinctive properties in tracking or tagging molecules. Some look for ways to tune reactivity through new synthetic modifications, or to repurpose this core for applications in sensing, catalysis, or advanced materials. The compound’s long past in academia, industry, and education gives it a deep well of case studies and practical guidance, ensuring that even as chemistry changes, 3,5-dinitrobenzoic acid will keep offering both challenges and opportunities for generations to come.
Working in a lab, I've run into a cabinet full of chemicals that aren’t exactly household names. 3,5-Dinitrobenzoic acid caught my eye early on—not for its fame, but for the way people depend on it quietly in the background of scientific work. It’s a yellowish solid, not exactly spectacular to look at, but this simple aromatic acid has carved out multiple uses, especially in analytical chemistry.
Ask any organic chemist about classic test reagents, and 3,5-dinitrobenzoic acid comes up. When you synthesize an alcohol in the lab, especially if you’re checking its purity, you don’t just trust your eyes. Making esters of that alcohol using this acid provides a quick and pretty reliable fingerprint—no expensive instruments needed. The esters tend to crystallize out with sharp melting points, which you can compare against published values. In undergrad labs across the world, this trick saves time and weeds out impurities, keeping processes honest. The act of making derivatives for confirmation remains a practical approach, especially in research environments with tight budgets.
Beyond identification, this compound finds consistent use for spotting functional groups within unknown mixtures. Reacting it with various compounds often results in observable changes—sometimes a color change, other times a crystal formation. These changes reveal the presence or absence of certain alcohols or amines, which can make problem-solving much faster. Analytical techniques have gone digital, but the value of hands-on chemical tests still holds. As someone who started out before high-resolution mass spectrometry was everywhere, I've seen reliance on these old-school methods pay off when newer tech sputtered or data looked ambiguous.
Pharmaceutical research also appreciates the practicality of 3,5-dinitrobenzoic acid. By giving a clear way to confirm molecular structure, it indirectly supports the discovery process. Purity isn’t just an academic concern—impurities in a potential drug can lead to failed trials or worse, cause harm. Having a chemical that makes it easy to check—without extra machines or delays—cuts costs and improves the odds that a drug in development stays on track. Industrial suppliers keep it on their lists, knowing it's a necessary tool for research and development work in both big pharma and academic circles.
Routine work with chemicals like 3,5-dinitrobenzoic acid calls for some respect. It contains two nitro groups, and that brings along certain risks—including sensitivity to shock and possible toxicity. In my experience, responsible handling, gloves, a well-ventilated workspace, and clear labeling go a long way. Disposal rules often specify special waste streams, as you don’t want this compound turning up where it shouldn’t—either in drainage or landfill. Modern labs now lean toward green chemistry, using the smallest amounts needed while always considering safer alternatives if possible. Balancing efficiency and safety means following guidelines from trusted regulatory bodies and keeping up with the latest safety data.
One solution I saw firsthand involved more hands-on safety training and better labeling protocols. Accidents dropped, and confidence went up. Colleges and research facilities could expand their digital databases for quick access to safety and disposal information. Personally, I’d also like to see more workshops on how to switch to less hazardous alternatives when they exist, and how to use traditional tools more effectively—because future breakthroughs rely on both the old and new ways working together.
3,5-Dinitrobenzoic acid catches attention with its sharp name and even sharper chemistry. Its molecular formula looks simple at a glance: C7H4N2O6. At the core sits a benzene ring holding a carboxylic acid group and two nitro groups. Both nitro groups latch onto the third and fifth positions of the ring, which changes how the molecule behaves compared to its parent, benzoic acid.
During university years, it wasn’t uncommon to fumble over naming or drawing aromatic acids. Each detail matters—where those nitro groups attach, what they do to acidity, and how the molecule interacts with other compounds. In organic labs, the addition of nitro groups to the ring always shifted a chemical’s character: the color, the reactivity, even the way it dissolved in solvents bore the fingerprints of those tiny yet mighty atoms.
The world's not short on aromatic acids, yet this one keeps turning up in labs and industry settings. It plays a role in identifying and separating different compounds. Years ago, running melting point tests on a batch of organic acids for purity, I remember 3,5-dinitrobenzoic acid stood out—higher melting point, sharper crystallization, vivid chemicals you don’t soon forget. Its strong electron-withdrawing groups boost the acidity compared to benzoic acid, making the molecule a handy tool in refining mixtures and working out structures in organic chemistry.
Beyond the lab, C7H4N2O6 has a place in pharmaceutical chemistry. When researchers hunt for certain reaction products or chase down elusive intermediates, this compound offers clarity in spectroscopic signatures and separation. Out in the real world, this translates to better quality control and more effective drug development.
Working with 3,5-dinitrobenzoic acid brings up those old lab safety lectures: gloves, goggles, fume hood. Nitro compounds deserve respect. They’re sensitive—easy to mishandle, potentially toxic if ignored. If protocols get sloppy, risks shoot up quickly. This isn't anecdotal: nitro-aromatics are notorious for their health concerns. The best labs obsess over air quality and waste disposal when these chemicals come off the shelf.
On a larger scale, chemical manufacturers face pressure to keep these substances from leaching into ecosystems. Nitroaromatic pollution means real damage—mutated aquatic life, poisoned groundwater, brown stains where green once grew. Factories posting safety data sheets isn’t enough. We need strict monitoring, practical training, and adoption of safer alternatives when possible. Some researchers now tweak nitroaromatic synthesis to use less harsh reagents or run processes closer to ambient conditions, both to save energy and improve safety.
Chemistry students need hands-on experience with acids like this one. Schools and industries benefit from clear, updated safety manuals that shift with the latest findings, not just posters taped to a lab fridge. At one point, older colleagues made a habit of recounting chemical mishaps—what went wrong, what they’d do differently. That kind of storytelling, grounded in hard experience, does more for instilling caution than any rulebook.
The formula C7H4N2O6 stands for more than its atoms. It symbolizes the daily discipline, respect for potential harm, and curiosity that keeps science inching forward without leaving disaster in its wake.
Working in a chemistry lab rarely feels like the world of textbooks and demonstrations. Each container and compound in a lab has a unique character — some stubborn, others dramatic, a few prone to making trouble if you don’t pay attention. 3,5-Dinitrobenzoic acid holds a spot in the lab bestiary that calls for respect. A solid organic compound, it shows up as a yellow powder, known for its use in identifying alcohols and phenols. But behind those uses sits a quiet need: safe and responsible storage.
I’ve met many lab newcomers who look at a bottle’s hazard symbols and assume all acids belong on the same shelf. Anyone who’s spent time grooming inventory knows this approach can cost dear, both in safety and in product reliability. 3,5-Dinitrobenzoic acid brings its own set of requirements. Its nitro groups and acidic function make storage decisions more than paperwork. They shape shelf life, influence contamination risk, and guard against surprises.
A climate-controlled store room helps maintain structure. Temperatures near room temperature usually work, as extreme heat or cold messes with the purity and physical stability of the crystals. Avoiding sunlight makes sense; light can sometimes play tricks on sensitive organics, speeding up degradation without much warning.
Physical separation from strong bases ranks high on my list. The wrong neighbor can lead to spills or unwelcome reactions, especially where moisture or carelessness shows up. Keeping incompatible chemicals apart, using secondary containment if space runs thin, blocks accidents before cleanup becomes an issue.
The dry factor deserves its own spotlight. Once, a careless lab mate left the cap loose, and humidity clumped the powder like old sugar. Moisture seeps in and encourages hydrolysis or just ruins the measurement in a precise experiment. I store 3,5-dinitrobenzoic acid in tightly closed glass bottles, with a desiccant pouch in crowded seasons or climates. Screw caps leave less room for error than loose stoppers or parafilm that looks secure but can peel when no one’s watching.
Labeling stands as more than a formality. Clear, legible writing, hazard pictograms in view, and chemical identity in full never hurt. Outdated handwriting or mystery bottles crammed behind reagents led to near-misses in more labs than anyone cares to admit. I keep Safety Data Sheets handy and stress to newcomers that “I know what’s in there” means nothing during emergencies or inspections.
Spill response measures share shelf space, too. Absorbent pads, proper gloves, and goggles wait within reach of storage spots. No one schedules a spill, and guessing can make things worse. I keep an updated log of inventory, periodically checking for any deterioration or signs of leaks. In my experience, early intervention saves more than product — it preserves the overall integrity of storage areas, shielding everyone from costly and preventable headaches.
Chemicals like 3,5-dinitrobenzoic acid never sit in a space alone. Human behavior shapes safety, from the first delivery to final disposal. Training staff in proper handling and regular audits foster a habit of awareness. I’ve seen that open conversation about safety and shared responsibility builds trust. These compounds support progress in research and education, provided their risks get treated with respect. That respect starts with day-to-day storage and grows from there.
3,5-Dinitrobenzoic acid comes from the family of nitrobenzoic acids, typically recognized in laboratories and some industrial work. While the compound may help in chemical syntheses or serve as a reagent, its hazards deserve real attention from anyone handling it, whether in a research or industrial setting. I’ve always believed that understanding chemicals isn’t just about formulas; it’s about the real risks one might face on a daily basis. For 3,5-Dinitrobenzoic acid, safety doesn’t start with gloves—it starts with honest awareness.
The biggest concern comes from its toxicity. Inhaling dust or vapors may create real respiratory problems. I once saw a graduate student ignore dust protocols and end up with a nasty cough that took weeks to clear. Data from various safety sheets backs this up, showing irritations to the nose, throat, and lungs. Any contact with the eyes or skin could cause burning, redness, or itching. Once upon a time, I got a few granules on the back of my hand—it felt like a bee sting followed by redness that didn’t fade quickly.
If swallowed, the toxicity can quickly move from mild symptoms like stomach pain to more serious symptoms. Some cases mention nausea, headache, and even strong allergic responses. Animal toxicology studies tie nitro-aromatic compounds to organ effects, especially after repeated exposure.
Environmental risk hangs over any compound with two nitro groups. Spilling 3,5-Dinitrobenzoic acid near water sources or poorly managed waste streams could disrupt aquatic life. Nitro compounds don’t always break down easily, so they linger in the ecosystem. Agencies like the EPA have flagged these types of chemicals for extra scrutiny, especially in sensitive environments. If you’ve seen a runoff incident in a lab, you’d recognize how fast these risks snowball.
Fire brings out another troubling side. Many forget that nitro-based compounds feed flames instead of slowing them. During storage, a spark or heat wave could trigger combustion, releasing toxic gases. Nitrobenzenes create nitrogen oxides when they burn, which affect health and harm the surrounding air quality. I remember being on fire watch in a student lab; even a few grams near a heat source raised alarms.
No substitute exists for solid training. People working with this compound need well-fitted gloves, coats, and goggles. Lab ventilation matters much more than some realize. Simple things like dust masks and regular clean-up duty save a lot of discomfort and risk. I’ve found that safety briefings help cut down on careless mistakes. Emergency showers or eye-wash stations change close calls into minor hiccups.
Storage should always be away from heat, sunlight, and incompatible materials like strong bases and reducing agents. Secondary containment can save lives, especially in shared spaces. Labeling and documentation make all the difference during emergencies, since first responders know exactly what they are dealing with.
Disposal isn’t straightforward. Leaving this compound in regular trash puts more than the environment at risk—it risks people’s health downstream. Following hazardous waste guidelines, sending material through certified facilities, and never rinsing down the drain form the backbone of responsible disposal.
Staying informed about chemicals like 3,5-Dinitrobenzoic acid means balancing knowledge, practical steps, and a little humility about what can go wrong. I’ve seen curious students and experienced researchers alike fall into habits; constant reminders and upgrades in safety make a real difference. Facts guided by actual lab stories make the threats tangible, and addressing them helps prevent harm to people and the planet.
Organic labs always have distinct smells that cling to your clothes, even after you’re long out of class. Stepping into procedures involving nitration, you feel the mood get a bit heavier because you’re dealing with acids that stain skin yellow and can singe noses. 3,5-Dinitrobenzoic acid comes from such gritty origins. It’s made by adding two nitro groups to benzoic acid—replacing hydrogens at the 3 and 5 positions of the aromatic ring.
Production starts with benzoic acid, something you find mostly in food preservatives and certain skincare products. In the lab, the common route uses a nitration mixture— concentrated sulfuric acid and concentrated nitric acid. The process calls for cooling and stirring, as heat can make things go sideways fast. If you try to shortcut, the mixture fizzes or darkens. Too hot, and you get a windshield of yellow fumes, sometimes leading to swap-in products rather than the clean dinitrobenzoic acid you intend.
Pouring benzoic acid into cold, concentrated sulfuric acid and slowly adding concentrated nitric acid has a way of making you respect goggles and fume hoods. Stirring prevents hot spots. The temperature often hovers below 15°C, as overheating triggers side reactions—you’re not aiming for trinitrobenzoic acid or tarry residues. Once the acids do their work, you pour the slurry into ice water. Here, the yellow crystals of crude 3,5-dinitrobenzoic acid crash out suddenly. Not the prettiest, but effective.
Next comes filtration and washing. Impurities cling, so cold water comes into play before any thought of ethanol or crystallization. Recrystallization from ethanol gives the best shot at clean crystals. During my time in academic labs, seeing the transformation from brownish goop to golden needles always felt satisfying—usually the best guess that the procedure worked as intended.
On paper, mixing chemicals and making crystals seems straightforward. In practice, nitration demands respect. Sulfuric acid burns skin instantly. Nitric acid attacks clothes and skin, tissues, and if mishandled, creates nitrogen oxides that can irritate lungs for hours. I once saw a classmate ignore cooling instructions; brown fumes filled the hood and prompted an evacuation. Mistakes linger in memory longer than most lectures.
Medical and industrial fields need 3,5-dinitrobenzoic acid for research, detection of certain aldehydes, and as a reference material. Its production must follow safety procedures, not just for purity but for protecting everyone in the lab. Reports from chemical safety boards warn about accidents involving acid-handling, especially among students or poorly trained technicians. Recognizing the importance of cooling, steady stirring, and using plenty of ice pays off every single time.
Chemists continue to develop ways of making nitration less hazardous. Micro-scale reactions reduce the amount of explosive product and acids, making those undergraduate labs safer overall. Modern methods can swap out the old nitration mixture for milder reagents or safer solvents under controlled conditions. Automation and enclosed reaction setups take people further from direct exposure.
The foundation for safety remains unchanged—detailed preparation, commitment to proper gear, thorough instruction. Mixing nitric and sulfuric acid remains inherently risky. I’ve seen experienced chemists pause before measuring out each ingredient. That moment of checking—a quick double-take at protocols—makes all the difference. Anyone working through this synthesis holds not only their learning, but also their well-being, in their hands.
| Names | |
| Preferred IUPAC name | 3,5-dinitrobenzoic acid |
| Other names |
m-Dinitrobenzoic acid 3,5-Dinitrobenzoic acid Benzene-1,3-dicarboxylic acid, 5-nitro- DNBA |
| Pronunciation | /ˌθriː,faɪv daɪˌnaɪ.trəʊ.bɛnˈzoʊ.ɪk ˈæs.ɪd/ |
| Identifiers | |
| CAS Number | 99-34-3 |
| Beilstein Reference | 88264 |
| ChEBI | CHEBI:34603 |
| ChEMBL | CHEMBL1539 |
| ChemSpider | 1678 |
| DrugBank | DB04452 |
| ECHA InfoCard | 100.006.003 |
| EC Number | 204-234-4 |
| Gmelin Reference | 85294 |
| KEGG | C01167 |
| MeSH | D004075 |
| PubChem CID | 9842 |
| RTECS number | GN8575000 |
| UNII | D2J19U7MAM |
| UN number | UN1320 |
| Properties | |
| Chemical formula | C7H4N2O6 |
| Molar mass | 212.11 g/mol |
| Appearance | Yellow crystalline powder |
| Odor | Odorless |
| Density | 1.683 g/cm³ |
| Solubility in water | slightly soluble |
| log P | 1.84 |
| Vapor pressure | 1.58E-7 mmHg at 25°C |
| Acidity (pKa) | 3.42 |
| Basicity (pKb) | 1.14 |
| Magnetic susceptibility (χ) | -52.1·10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.664 |
| Viscosity | 1.34 mPa·s (at 25 °C) |
| Dipole moment | 2.53 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 202.2 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | −428.2 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -1469.8 kJ/mol |
| Hazards | |
| Main hazards | Harmful if swallowed, causes serious eye irritation, may cause respiratory irritation |
| GHS labelling | GHS02, GHS07, GHS09 |
| Pictograms | GHS07,GHS09 |
| Signal word | Danger |
| Hazard statements | H302, H315, H318, H335 |
| Precautionary statements | P261, P264, P270, P271, P301+P312, P304+P340, P305+P351+P338, P312, P330, P403+P233, P405, P501 |
| NFPA 704 (fire diamond) | Health: 2, Flammability: 1, Instability: 1, Special: - |
| Flash point | 230 °C |
| Autoignition temperature | > 585 °C |
| Lethal dose or concentration | LD50 oral rat 320 mg/kg |
| LD50 (median dose) | LD50 (median dose): 1600 mg/kg (oral, rat) |
| NIOSH | GM3150000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | 0.1 mg/m3 |
| IDLH (Immediate danger) | Unknown |
| Related compounds | |
| Related compounds |
Benzoic acid 3-Nitrobenzoic acid 4-Nitrobenzoic acid 2,4-Dinitrobenzoic acid 2,6-Dinitrobenzoic acid m-Nitrobenzoic acid |
