Back in the 1970s and 80s, researchers combed through sulfur-containing heterocycles in search of bioactive molecules. Early curiosity about benzothiophenes picked up in the lab, especially as pharmaceutical companies started noticing that tiny tweaks to aromatic rings led to surprising effects in hormone-related compounds. 7-Methoxy-5-methylbenzo[b]thiophene caught the eye because its scaffold showed both aromatic and electron-rich behavior, a combination that gave chemists flexibility. Over the years, modifications on thiophene rings, particularly with strategic methyl and methoxy groups, have unlocked targeted pharmacological activity, that wouldn’t be possible without a deep understanding of aromatic substitution and sulfur’s lone pairs. As scientists developed more accurate techniques in chromatography and mass spectrometry, it became much easier to purify and characterize such specialty chemicals, laying a foundation for rapid prototype testing in drug discovery and beyond.
7-Methoxy-5-methylbenzo[b]thiophene stands as a specialty heteroaromatic compound. Its popularity owes much to how it bridges the electronic nuance of benzene’s aromatic ring with the unique reactivity of sulfur in the five-membered thiophene. Chemists value it as an intermediate for synthesizing more complex molecules, especially those that imitate biological activity found in natural-product inspired drugs. Whether for making polymers that require unique electronic characteristics, or in the refinement of agricultural chemicals, this compound provides foundational "building block" status, and its structure lends itself to functionalization in several directions.
This compound doesn’t shy away from the typical profile you’d expect of a fused thiophene: off-white to light yellow crystals or powder, easy to weigh, not much perceptible odor. It sports a melting point in the range of 70-80°C. The methoxy and methyl groups push electron density into the aromatic system, which appears in its NMR signatures and makes the molecule just reactive enough in standard electrophilic aromatic substitution. The logP leans toward moderate hydrophobicity, which can be important in predicting how it interacts with enzymes or membranes. Its solubility pans out well in common polar aprotic solvents, essential for organic synthesis workflows.
Quality manufacturers provide tight specifications on purity, with trace contaminants listed and batch-to-batch variability minimized. Labels detail CAS number, molar mass, and clear hazard warnings: flammable solid, eye and skin irritant, and required PPE for handling. Storage recommendations call for a cool, dry place, away from incompatible oxidizers. SDS (Safety Data Sheet) documentation describes these hazards in plain language so even researchers less familiar with sulfur compounds know what to expect during use.
Most published syntheses begin with a well-placed Friedel–Crafts acylation, often starting from a methylated methoxybenzoic acid, followed by ring-closure with sulfurizing reagents under acidic conditions. Others lean on palladium-catalyzed cross-coupling, such as Suzuki or Stille, especially for laboratories emphasizing higher selectivity and cleaner profiles with less waste. Key parameters: controlling temperature spikes, rigorous exclusion of moisture and air during transition metal catalysis, and robust purification by silica gel chromatography or recrystallization to ensure isolation of the pure heterocycle. The overall yield can fluctuate based on the discipline of the chemist, solvent quality, and batch scale, but with optimized conditions, results generally stand in the 60-80% range.
Synthetic chemists see 7-methoxy-5-methylbenzo[b]thiophene as a versatile partner in cross-coupling reactions, especially at the 2-position of the thiophene. Electrophilic aromatics, such as halogenations or nitrations, proceed predictably, influenced by the electron-donating methoxy and methyl. Functionalizing the methoxy group with demethylation strategies, or tuning the methyl into a carboxyl group through oxidation, expands its range. Some researchers also explore lithiated intermediates at low temperatures, exploiting regioselectivity given by the substituents. For complex molecule assembly, this backbone welcomes derivatization through well-established transition metal chemistry, opening avenues for both diversification in small-molecule libraries and exploration in organic electronics.
In catalogs and research papers, the compound might show up as 7-methoxy-5-methyl-1-benzothiophene or 5-methyl-7-methoxybenzothiophene. These synonyms crop up depending on the naming conventions of suppliers, or the IUPAC adherence of academic journals. Occasionally, proprietary identifiers or catalog numbers from chemical vendors arise, but the key descriptors remain tied to the position of the methyl and methoxy groups on the benzothiophene scaffold.
Working with aromatic thiophenes demands a respect for both their reactivity and long-term handling effects. Lab staff stick with nitrile or neoprene gloves, goggles, and fume hoods, not just to avoid direct exposure but to prevent inhalation of dust or vaporized residues. Clean-up and disposal protocols rely on halogenated organic waste streams; never directly into general waste or sinks due to potential persistence in water systems. Vendors and institutions adhere to OSHA and REACH guidelines, updating SDS documentation in light of new toxicology reports and disposal insights.
Industries ranging from pharmaceuticals to materials science make use of benzo[b]thiophene derivatives. Medicinal chemists value the scaffold when creating SERMs (selective estrogen receptor modulators) and other hormone-linked molecules; these adjustments can radically shift biological targeting. In the world of organic electronics and OLEDs, chemists appreciate sulfur-containing rings for their influence on electronic transport properties. Early-stage pesticide development also benefits, since the core interacts efficiently with certain enzyme targets in pest species. Its adaptability stands out, with researchers always seeking new indications or material properties by branching from this foundation.
Academic and private research push this molecule into new frontiers. Automated synthesis platforms allow for quick generation of analogue libraries, which shortens timelines from hypothesis to biological screening. Structure-activity relationship (SAR) studies map out how subtle shifts in substituents impact potency and selectivity, feeding insight to both human and animal health efforts. High-throughput assays combined with advanced analytics, such as LC-MS/MS and cryo-EM, deliver data on how these molecules fit into enzymes or receptors at the atomic level. Cutting-edge work looks to marry traditional organic synthesis with green chemistry, striving to reduce solvent loads and hazardous reagents, all while scaling up bench science for real-world applications.
No good lab ignores toxicity. In vitro cytotoxicity assays and in vivo animal studies provide the benchmarks for safe exposure. Most findings flag aromatic thiophenes as mild irritants, with some leading to liver enzyme induction at high doses. Chronic exposure in rodent models occasionally shows weak carcinogenic potential, pushing regulatory agencies to enforce proper labeling and limit occupational exposures. Risk assessment also catalogs potential for aquatic toxicity—this family often resists breakdown in municipal water treatment, so environmental monitoring tracks any releases from manufacturing sites or academic facilities. Toxicologists continue to look for metabolic pathways that either detoxify or highlight risks, vital for anyone scaling up usage or pursuing regulatory approvals.
The future for 7-methoxy-5-methylbenzo[b]thiophene looks bright, but responsible. Newer generations of chemists take up the challenge of molecular innovation while keeping sustainability in mind. Confident strides in computational modeling and machine learning predict fresh targets for the scaffold, venturing beyond human health into smart materials and energy. Synthetic biology could someday coax microbes into making such heterocycles, bypassing harsh chemical processes. Regulatory science evolves too, nudging every industry partner toward transparency about both benefits and risks. The road ahead won’t just dig deeper into what this molecule can do, but how it fits within the bigger story of safer, smarter, and more sustainable chemistry.
7-Methoxy-5-methylbenzo[b]thiophene sounds like the kind of compound that only matters in a chemistry lab, but real-world uses give it relevance beyond textbooks. Over the years, people in pharmaceutical research, agrochemical development, and advanced materials science have found reasons to work with this specific molecule. The variety stems from how the benzo[b]thiophene structure works in complex organic syntheses. I’ve seen chemists choose it when they want to add something unique to a mix—something that changes how a new molecule behaves.
Any conversation about 7-methoxy-5-methylbenzo[b]thiophene tends to touch on its role as a building block in drug development. Medicinal chemistry looks for molecules that either act as drugs themselves or help craft active ingredients for future medicines. The benzo[b]thiophene group shows up in treatments that range from hormone therapies to cancer research agents. Drug designers don't pick random molecular backbones; they seek stability, activity, and selectivity. This compound, with its sulfur-containing ring and precise substitutions, brings a combination of those traits.
In practical lab work, teams often use it as an intermediate—something that isn’t the finished drug, but a step along the way. The methoxy and methyl groups on the ring change how enzymes and cell receptors interact with the molecule. This property can make a key difference in how a drug will act in the body, whether it’s more stable, more targeted, or less likely to break down too quickly.
7-Methoxy-5-methylbenzo[b]thiophene pops up in agrochemical circles too. Pesticide designers have experimented with benzo[b]thiophene derivatives due to their potential to disrupt the growth or reproduction cycles in pest species. The logic is straightforward: if a compound can target one biological pathway in harmful insects or weeds, it can create a better, more specific product. Some new fungicides and herbicides start with molecules similar to this one, letting researchers tweak side groups to improve safety or performance.
Agricultural scientists find benefit in using such specialized compounds because resistance appears less quickly and non-target species can be spared. There’s no magic bullet for safe pest control, but careful design—using core molecules like this one—edges closer to that ideal.
Researchers working on polymers and advanced coatings sometimes pull from the benzo[b]thiophene family. Compounds like 7-methoxy-5-methylbenzo[b]thiophene offer stability alongside electronic features, which can help create materials for sensors, organic semiconductors, and photoactive films. For example, when looking to improve the charge transfer qualities in flexible electronics, the position and nature of the substituents on aromatic rings start to matter a lot more. Adding a slight twist—like a methoxy or methyl—shifts the performance metrics. I’ve seen small changes in chemical design lead to new patents and product launches, especially as wearables and new energy devices keep growing.
In my experience, researchers driven to solve tough problems will always look for molecular backbones that deliver a mix of reactivity and selectivity. 7-Methoxy-5-methylbenzo[b]thiophene fits nicely into that toolbox—enabling experiments that could lead to safer medicines, smarter crop solutions, and more efficient electronic materials. Its versatility reminds us that real progress in science often starts by tinkering with the basics, swapping groups or atoms on a ring, just to see what new possibilities can emerge.
In chemical research and manufacturing, the stated purity of a compound like 7-Methoxy-5-MethylbenzoBThiophene drives more than raw numbers on data sheets. Purity shapes outcomes in analytical results, impacts safety during use, and influences long-term trust between buyers and suppliers. From working at a lab bench, I’ve learned that even fractional differences in purity lead to night-and-day results in organic synthesis projects.
Most chemical suppliers advertise purities as a percentage by weight, commonly quoted as “greater than 98%.” Years ago, I spent hours sorting through little white bottles, squinting at minuscule print on labels for numbers like “97%,” “98%,” “99%,” hoping for the highest grade. For bench chemists and analysts, a compound hovering around 98% might fit most screening needs, but complex chemical reactions or medicinal chemistry work demand even greater confidence.
Let’s say 7-Methoxy-5-MethylbenzoBThiophene comes with certificates of analysis (CoA) listing HPLC or GC purity at 98.5%. This means a small but measurable portion contains unidentified impurities—traces of solvent, residual starting materials, or byproducts from synthesis. Even a fraction of a percent matters if those impurities carry biological activity or throw off analytical instruments. In drug discovery, these traces muddy things further. Medicinal chemists have learned the hard way: a mystery peak in an NMR printout, or a fuzzy spot on a TLC plate, can waste weeks of work.
Reliable purity measurements don’t happen by guessing. Analytical techniques like high-performance liquid chromatography (HPLC) and gas chromatography (GC) do the heavy lifting. These tools expose unintended byproducts, quantifying them with solid accuracy. Spectroscopic methods, especially NMR and mass spectrometry, help confirm identity and flag problems invisible to other tests. Professional suppliers won’t just list “>98%” and call it a day—they’ll share representative chromatograms, spectra, and data from actual production batches.
Many reputable vendors follow strict standard operating procedures. They store samples in tightly closed amber bottles, sometimes under nitrogen gas, to keep air and light from degrading sensitive chemicals. Labs that test every new lot on arrival can catch any purity drops over time and spot inconsistencies before any chemistry begins.
Folks rely on proper documentation rather than flashy claims. Certificates of analysis ought to list testing dates, batch numbers, methodology details, and often impurity profiles. Anyone ordering 7-Methoxy-5-MethylbenzoBThiophene should check for this documentation before use—if a supplier refuses to provide a CoA, that’s a red flag. My old mentor insisted on keeping every CoA on file, dating each bottle received, and cross-referencing test results with our own in-lab checks.
Chemists and researchers can look for suppliers that provide third-party testing or meet ISO quality standards. Producers gain loyalty by overdelivering on transparency, showing up with extra information beyond just a percentage value. Investing in proper storage and timely shipping keeps the compound from degrading on the shelf or on the road.
Purity isn’t just about numbers. Solid science, trustworthy suppliers, and rigorous self-checks keep research moving forward, and experience on the lab bench shows the difference with every successful experiment.
Anyone who has spent time in a laboratory knows the frustration of discovering a ruined reagent. Chemicals that fail because of poor handling waste both money and time, and sometimes lead to inaccurate results. I've found that thiophene derivatives, especially ones with sensitive functional groups, show these vulnerabilities. Sensitivity to light, heat, and moisture comes up more often than one expects. This makes good storage more than a box to check—it's part of good scientific practice.
Refrigerators aren’t just for lunch. 7-Methoxy-5-Methylbenzo[B]Thiophene tends to hold up best at lower temperatures. Storing this compound between 2 and 8 °C slows down unwanted reactions like oxidation or hydrolysis. Fluctuations in temperature work against stability, so consistent refrigeration instead of cycling in and out of cold keeps this compound within tight specs.
Light-triggered reactions can sneak up and cause yellowing or even breakdown in similar compounds. Real-world experience—like opening a container of an aromatic compound left near a sunlit bench—shows how even a bit of daylight can speed up decomposition. Opaque bottles or amber glass containers stop this from happening to a great extent. Tight-sealing those bottles keeps air out, which stops moisture from creeping in and stops oxygen from causing oxidative degradation.
In my time around synthetic labs, silica gel packs tucked in chemical cabinets always caught my eye. Keeping 7-Methoxy-5-Methylbenzo[B]Thiophene away from ambient humidity with a desiccant—especially after opening—really matters. Sometimes humidity isn’t obvious, but compounds like this pick up water and start clumping or degrading. Even a little water can change the course of a planned reaction. Regular checks of storage conditions become a habit; that means checking for condensation in bottles and swapping out worn desiccants.
Sloppy labeling leads to confusion and wasted effort. The name, storage temperature, date received, and any hazard codes should go on each container. From past experience, a lab notebook or an electronic record saves the team from mystery origins or uncertainty about age. Regulatory spot checks and audits tend to favor teams with transparent logs.
Chemical storage isn't just about the shelf; it's about people. Good ventilation, flameproof storage if required by safety data, gloves, eye protection, and knowing where materials are located—all of these lower the risk to everyone sharing that space. Time spent on safety pays off for the whole group. I’ve seen near-misses turn into nothing more than a story because someone followed protocol, and the right chemical sat in its correct spot.
Training for new lab members should always include real conversations about storage. No one remembers every guideline from a three-inch binder, but hands-on lessons with visible labels and cold-storage procedures stick. Posting a practical storage protocol next to refrigerators and storage cabinets puts those rules front-and-center, reinforcing good habits.
Investing in sturdy, lockable refrigerators and clear inventory management tools creates a culture of responsibility. Backing that up with regular team reviews makes successful storage part of how labs succeed together, not just a task for one person or one day.
Chemical safety might seem like a slog, but if you’ve ever handled anything beyond table salt, you know how fast things can go south without the right information. In labs, the Safety Data Sheet—or SDS—acts as a lifeline. People want to know: is there an SDS for 7-Methoxy-5-Methylbenzo[B]Thiophene? And if not, why does it matter so much?
I remember back in undergrad chemistry, a spilled beaker sent everyone scrambling. At that moment, we grabbed the SDS binder. The data sheet gave straight answers about hazards, first aid, and cleanup steps. No guessing, no confusion. Without the SDS, one missed hazard can lead to skin burns or worse. For researchers mixing 7-Methoxy-5-Methylbenzo[B]Thiophene, having that sheet nearby means the difference between a quick recovery and a hospital trip.
Not every chemical boasts a famous name or shows up in every catalog. This thiophene derivative falls into that camp. Still, manufacturers creating or importing chemicals are asked to generate an SDS under OSHA’s Hazard Communication Standard in the US, or similar rules in Europe and elsewhere. It doesn’t matter whether the substance is obscure or popular. If you sell it, offer it for research, or move it across borders, an SDS isn’t just helpful—it’s required.
I’ve run into this myself working in a university lab. Smaller suppliers sometimes try to get away with a bland technical sheet or “use at your own risk” statements. This doesn’t cut it. Without a detailed breakdown of hazards, accidental contact or inhalation can lead to injuries nobody saw coming. If the manufacturer doesn’t offer an SDS, alarm bells start to ring.
The hazards for benzo[b]thiophenes run the gamut: some irritate eyes or skin, others create fumes that harm lungs. A good SDS spells out hazards with clarity. Route of exposure, symptoms, proper glove materials, spill cleanup procedures—all lined up in black and white. Those details support trust, because people need to know they’re not gambling with their health or their job.
Lack of information slows down work, too. If a researcher must pause to hunt through academic papers or piece together scattered notes, project deadlines slip. Risks rise. I’ve seen senior scientists halt an entire synthesis because a single sheet wasn’t available. That kind of delay hits productivity and makes people anxious about what else safety prep might be missing.
If you run into a blank wall searching for an SDS, contact the supplier right away. Request the required safety paperwork. If they won’t hand it over, consider switching to a reputable distributor. Government agencies, university EH&S teams, and chemical registries sometimes help fill in the gaps—they may have templates or related sheets for near-identical molecules.
Bottom line: shortcuts with chemical safety backfire, every time. An SDS for compounds like 7-Methoxy-5-Methylbenzo[B]Thiophene lets workers make decisions that save fingers, lungs, and sometimes lives. That’s not paperwork for paperwork’s sake—it’s peace of mind built on solid, transparent facts.
Chemistry often looks mysterious until people pin a compound down with hard numbers. 7-Methoxy-5-methylbenzo[b]thiophene isn’t a household name, but its unique fingerprint comes from its molecular weight, 178.24 grams per mole, and its Chemical Abstracts Service (CAS) number, 41141-69-7. These numbers do more than fill data sheets. They make a tidy bridge between invention and application, turning dense scientific jargon into useful, trackable information. Accurate identifiers keep compounds from being lost or confused as research moves from bench to industry.
My background in an academic research lab, as well as brief work with a pharmaceutical startup, made it clear how a single digit in a CAS number can spell the difference between a useful reagent and an experiment that veers off course. 7-Methoxy-5-methylbenzo[b]thiophene serves as a good example because tweaks in the arrangement of atoms can spawn close relatives—each with different properties, uses, and risks. That’s where numbers earn their keep. A chemist can run an online database search for “41141-69-7” and pull up precise safety data, synthetic history, suppliers, and purity information. No mixed containers, no legal headaches, fewer surprises.
Numbers aren’t just a formality. They drive real choices in industry, regulation, and public safety. In pharmaceutical development, companies must tie every new ingredient to its CAS number from day one. Governments rely on these numbers when drawing up regulations, especially for compounds with environmental or health impacts. Mess up the molecular weight in the paperwork and a batch of chemicals might get quarantined at a border or pulled off the shelf. Knock-on delays cost jobs, stall research, and risk public trust.
Plenty of small labs still run on a shoestring. They sometimes copy down numbers by hand, or use outdated catalogs with stray typos. Automated systems sometimes choke on misspelled names or swapped digits. It’s not rare for custom-synthesis outfits and importers to tangle with mislabelled goods, and that can trigger financial or legal messes. The value of clear, up-to-date records isn’t always obvious until something goes wrong.
Stronger habits can fix these cracks. Labs benefit from cross-checking every chemical name and number with reliable registries such as those run by CAS, PubChem, or ChEMBL. Digital lab notebooks beat handwritten logs. Barcode and QR code tracking help spot errors early. At the larger scale, supply chains perk up with automation, directly linking supplier catalogs and research inventories. Together these steps cut down on miscommunication and waste.
Knowing the molecular weight and CAS number for a compound like 7-Methoxy-5-methylbenzo[b]thiophene is not a dusty detail. For researchers, regulators, and manufacturers, these identifiers unlock clarity and efficiency. Respecting them day-to-day means fewer headaches and safer results, which in turn builds the trust that modern science depends on.
![7-Methoxy-5-Methylbenzo[B]Thiophene](https://alchemist-1317689233.cos.ap-nanjing.myqcloud.com/056fcdf6-b156-4184-af3b-70a401d743ac/images/2d/7-methoxy-5-methylbenzo-b-thiophene.png)
![7-Methoxy-5-Methylbenzo[B]Thiophene](https://alchemist-1317689233.cos.ap-nanjing.myqcloud.com/056fcdf6-b156-4184-af3b-70a401d743ac/images/3d/7-methoxy-5-methylbenzo-b-thiophene.gif)
| Names | |
| Preferred IUPAC name | 7-methoxy-5-methyl-1-benzothiophene |
| Other names |
7-Methoxy-5-methyl-1-benzothiophene 5-Methyl-7-methoxybenzothiophene 7-Methoxy-5-methylbenzo[b]thiophene |
| Pronunciation | /ˈsɛvən ˈmɛθ.ɒk.si faɪv ˈmɛθ.ɪl ˈbɛn.zoʊ bi ˈθaɪ.oʊ.fiːn/ |
| Identifiers | |
| CAS Number | [43032-66-6] |
| Beilstein Reference | 417217 |
| ChEBI | CHEBI:139253 |
| ChEMBL | CHEMBL197157 |
| ChemSpider | 21738360 |
| DrugBank | DB04201 |
| ECHA InfoCard | 100.138.261 |
| EC Number | This compound does not have an assigned EC Number. |
| Gmelin Reference | 106896 |
| KEGG | C14394 |
| MeSH | D021921 |
| PubChem CID | 177648 |
| RTECS number | GQ3155000 |
| UNII | JWT717LU04 |
| UN number | UN3439 |
| Properties | |
| Chemical formula | C10H10OS |
| Molar mass | 178.24 g/mol |
| Appearance | white to light yellow powder |
| Odor | Odorless |
| Density | 1.23 g/cm³ |
| Solubility in water | Insoluble |
| log P | 2.8 |
| Vapor pressure | 0.0231 hPa at 25 °C |
| Acidity (pKa) | pKa = 7.63 |
| Basicity (pKb) | 7.77 |
| Magnetic susceptibility (χ) | -79.58 × 10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.613 |
| Dipole moment | 3.12 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 223.8 J·mol⁻¹·K⁻¹ |
| Std enthalpy of combustion (ΔcH⦵298) | -4840.2 kJ/mol |
| Hazards | |
| Main hazards | H315: Causes skin irritation. H319: Causes serious eye irritation. H335: May cause respiratory irritation. |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | H302, H315, H319, H335 |
| Precautionary statements | P280-P305+P351+P338-P337+P313 |
| Flash point | Flash point: 122.5 °C |
| Autoignition temperature | 430°C |
| LD50 (median dose) | LD50 (median dose): >2000 mg/kg (oral, rat) |
| NIOSH | HM9620000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | 10 mg/m³ |
| Related compounds | |
| Related compounds |
Benzo[b]thiophene 5-Methylbenzo[b]thiophene 7-Methoxybenzo[b]thiophene 6-Methoxybenzo[b]thiophene 5,7-Dimethoxybenzo[b]thiophene 5-Ethylbenzo[b]thiophene |
