5-Methyl-1,3-oxazole-4-carboxylic acid (CAS 103879-58-9), also named 5-methyloxazole-4-carboxylic acid, is a compact heterocyclic carboxylic acid with the molecular formula C₅H₅NO₃ and a molecular weight of only 127.10 g/mol. It presents as a light yellow powder, carries a methyl group at the 5-position and a carboxylic acid at the 4-position of the oxazole ring, and is commonly supplied at ≥95% (HPLC) or ≥98% purity depending on the supplier and grade. That small size is the molecule’s commercial argument. Unlike heavily substituted oxazole building blocks, 5-methyl-1,3-oxazole-4-carboxylic acid introduces the oxazole core with a defined substitution pattern that medicinal chemists can use directly, while the carboxylic acid at C4 provides a single, clean handle for amide-bond formation, esterification or cross-coupling. The 5-methyl group is not a passive spectator: it modulates the acidity (pKa), lipophilicity (LogP) and electronic properties of the oxazole ring, and those differences determine whether the resulting amide or heterocyclic product has the binding profile, metabolic stability and pharmacokinetic behaviour the programme needs. This is why the compound is not a generic “versatile building block” in the abstract. It is catalogued specifically as an intermediate for hinduchelins A–D, a family of iron-chelating antibacterials, and for CNS and inflammation drug leads, and it appears in medicinal chemistry campaigns targeting kinase inhibitors and heterocyclic scaffolds. The market for 5-methyl-1,3-oxazole-4-carboxylic acid is not a tonnage market. It is a research-to-pilot specialty chemical supplied in milligram-to-kilogram packages, with catalogue pricing that reflects its research-scale status: 1 g at €32, 5 g at USD 50, 25 g at USD 240–295 and 100 g at USD 885 from representative international suppliers. For buyers, the qualifying question is therefore not “what does a kilogram cost” but “which supplier can deliver a reproducible lot, with lot-specific analytical data, before the discovery programme loses time.”
Core Application Fields and Demand Architecture
Demand for 5-methyl-1,3-oxazole-4-carboxylic acid concentrates in three functional arenas where the 5-methyl-4-carboxy substitution pattern on the oxazole ring provides a combination of reactivity and physicochemical profile that other oxazole isomers cannot replicate: antibacterial and anti-infective lead discovery, kinase inhibitor and CNS drug discovery, and custom synthesis for medicinal chemistry programmes.
In antibacterial and anti-infective lead discovery, the compound is the key intermediate for hinduchelins A–D, a family of iron-chelating antibacterials. Iron chelation is a validated antibacterial strategy, particularly against pathogens that depend on iron acquisition for virulence, and the oxazole core in the hinduchelin scaffold contributes both metal-binding geometry and metabolic stability. The commercial significance of this application is tied to the intensity of antibacterial discovery funding rather than to any single clinical candidate, and it connects the building block to global health research streams that are less cyclical than commercial oncology spending.
In kinase inhibitor and CNS drug discovery, 5-methyl-1,3-oxazole-4-carboxylic acid functions as a heterocyclic acid building block for amide-bond formation with amines on kinase inhibitor scaffolds and CNS-targeted leads. The oxazole ring integrates readily into bioactive molecule design, particularly in medicinal chemistry campaigns targeting kinase inhibitors and heterocyclic scaffolds, and derivatives of 5-substituted oxazole-4-carboxylic acids have been evaluated for inhibition of blood platelet aggregation and for anticancer properties. The compound has also been identified as useful in the design of HSP90 inhibitors and other biologically active molecules. This is the segment where the building block’s value is highest, because the cost of an off-spec lot or a failed amide coupling is measured in lost synthesis time rather than in the price of the gram.
Custom synthesis and medicinal chemistry programmes form the third arena. Suppliers catalogue 5-methyl-1,3-oxazole-4-carboxylic acid as a research chemical and synthetic intermediate for pharmaceutical and agrochemical development, and offer it alongside custom synthesis and scale-up services. A programme that begins with a 250 mg or 1 g qualification lot may later require gram or tens-of-gram quantities under a locked specification, and the supplier’s ability to follow that transition without changing the analytical method or the impurity profile is part of the product’s value.
Regulatory Profile: A GHS07 Irritant with a TSCA Non-Listing That Requires Direct Supplier Confirmation
5-Methyl-1,3-oxazole-4-carboxylic acid is not a CMR substance and is not classified as a dangerous good for transport under standard conditions in most supplier assessments. Its regulatory identity is defined instead by a GHS07 irritant classification, a TSCA status that is consistently reported as not listed, and the analytical specifications that determine whether the material is fit for medicinal chemistry.
The hazard profile is that of a solid irritant. CookeChem’s SDS reports GHS07 with signal word “Warning” and hazard statements H302 (harmful if swallowed), H315 (causes skin irritation), H319 (causes serious eye irritation) and H335 (may cause respiratory irritation). Chem-Impex’s product page records “HazMat: No”, and AR-Reagent describes the material as typically classified as non-hazardous and shipped via standard ground or air transport with an MSDS. These are handling hazards and logistics conveniences, not carcinogenicity, mutagenicity or reproductive toxicity classifications, and the required precautions are standard for a fine-chemical solid: avoid dust generation, wear protective gloves and eye protection, use in a well-ventilated area, and store the container tightly closed at 0–8 °C.
The TSCA status is the single most consequential regulatory fact for U.S.-facing programmes. SynQuest Labs’ product record states explicitly: “Regulatory TSCA: Not listed on TSCA inventory”, and Chembase records “TSCA收录: false”. For a substance not on the TSCA Inventory, manufacture or import into the United States for commercial purposes would ordinarily require a Premanufacture Notice or an applicable exemption, most commonly the R&D exemption under 40 CFR 720.36 for research and development quantities used by or directly under the supervision of a technically qualified individual. This means the compound’s U.S. commercial pathway is currently structured around research-scale supply, and buyers intending to use it in process development must confirm that their supplier’s TSCA position supports the intended use. Suppliers that can provide a clear, lot-specific statement of TSCA status—rather than a generic catalogue field—add real qualification value for U.S. process chemistry groups.
For Russian and EAEU buyers, the compound is imported at research and pilot scale. The practical documentation expectations are a Certificate of Analysis reporting identity and purity by HPLC, a Russian-language SDS reflecting the GHS07 classification, and confirmation that the material is the 5-methyl-4-carboxy isomer rather than a positional analogue. The compound is typically stored at 2–8 °C or 0–8 °C under dry conditions, and a lot that has absorbed moisture or degraded during storage may still assay within specification but deliver poor results in an amide coupling, so packaging and storage discipline are part of the product’s fitness for use.
Global Supply Structure and Manufacturer Differentiation
Global supply of 5-methyl-1,3-oxazole-4-carboxylic acid is fragmented and research-oriented. The supplier landscape includes international research-chemical distributors and specialty producers such as Thermo Scientific, Chem-Impex, BOC Sciences, Fluorochem, ChemScene, CymitQuimica (Apollo Scientific brand), SynQuest Labs, Matrix Scientific, CookeChem and a cohort of Chinese custom-synthesis houses serving domestic and export demand. Purity specifications span ≥95% to ≥98%, and package sizes range from 250 mg and 1 g at catalogue scale to 5 g, 10 g, 25 g and 100 g, with bulk and custom-synthesis quantities available on request.
Differentiation operates on three axes. The first is analytical depth and lot-specific data. Suppliers that provide HPLC results for the specific lot, rather than a generic specification, reduce the buyer’s need to re-characterise material before use. In medicinal chemistry programmes, where the building block is incorporated into a complex inhibitor or antibacterial lead and purification is expensive, the cost of an off-spec lot is measured in lost synthesis time rather than in the price of the gram. The second axis is isomeric and purity control. The 5-methyl-4-carboxy substitution pattern must be distinguished from other oxazole positional isomers, and a lot that carries a positional impurity can behave differently in amide coupling and introduce a downstream impurity that is difficult to purge. Suppliers that report lot-specific HPLC purity and confirm the substitution pattern give the medicinal chemist a defensible basis for use. The third axis is scale-up and custom-synthesis capability. A supplier that can follow a programme from a 250 mg catalogue purchase to gram or tens-of-gram custom quantities, without changing the analytical method or the impurity profile, is more valuable than a catalogue vendor that cannot support the later stage.
Regional Demand Dynamics
Demand for 5-methyl-1,3-oxazole-4-carboxylic acid follows the geography of medicinal chemistry and biotech R&D rather than the geography of chemical manufacturing.
North America and Europe are the principal demand centres for the high-purity research-grade material, reflecting the concentration of antibacterial discovery, kinase inhibitor programmes, CNS drug discovery and contract research organisations in these regions. Demand is project-driven and small in absolute mass: a single medicinal chemistry group may purchase 250 mg to a few grams at a time, and a programme that advances may require tens of grams. The U.S. market carries the additional TSCA consideration described above, which tends to keep commercial flows at research scale unless an exemption or PMN pathway is established. European demand is similarly research-intensive, with buyers placing weight on supplier documentation, SDS availability and the ability to source from a supplier with a clear TSCA position for U.S.-linked programmes.
Asia-Pacific, and China in particular, is the manufacturing and stock-holding hub for the compound. Chinese producers offer the building block at 95–98% purity across package sizes from grams to larger custom quantities, serving both domestic pharmaceutical R&D and export markets. The region’s demand is growing as domestic drug-discovery research expands, and Chinese suppliers are increasingly capable of providing lot-specific analytical data alongside the product. For Russian and EAEU buyers, China is the most accessible source of supply, and the practical qualification task centres on verifying the Certificate of Analysis and the SDS rather than on navigating a complex regulatory approval pathway.
Russia and the EAEU form a small, import-dependent contour. Demand comes from pharmaceutical R&D, medicinal chemistry groups and custom-synthesis service providers, and supply is sourced from Chinese and international catalogue vendors. There is no meaningful domestic production of the compound, and the practical constraint is availability at the required purity and package size rather than regulatory restriction. Buyers in the region place a premium on suppliers that can provide a Russian-language SDS, a lot-specific Certificate of Analysis and reliable delivery of small packages, because a delayed gram can stall a synthesis campaign.
Future Outlook and Strategic Imperatives
The commercial trajectory of 5-methyl-1,3-oxazole-4-carboxylic acid is tied less to its own market size than to the therapeutic programmes it enables. The hinduchelin antibacterial scaffold and the broader oxazole kinase inhibitor and CNS lead space provide two demand streams that are connected to anti-infective and neuroscience research funding rather than to a single commercial cycle. The compound’s role in HSP90 inhibitor design and in antiplatelet and anticancer research adds further programme-driven demand. Custom synthesis adds a service layer that grows with every programme that chooses the 5-methyloxazole-4-carboxylate building block.
Three structural forces will shape the supply landscape. First, analytical transparency and substitution-pattern confirmation will remain the primary differentiators. As programmes mature, the building block’s purity and isomeric profile directly affect the purity of the final active, and buyers will increasingly require lot-specific HPLC data and confirmation of the 5-methyl-4-carboxy pattern rather than a nominal ≥95% figure. Second, the transition from catalogue to custom scale will separate suppliers that can support a programme’s growth from those that can only fill a small-pack order. A supplier that can lock a specification at 250 mg and reproduce it at gram or tens-of-gram scale, with the same impurity profile, will be preferred for process development. Third, the TSCA non-listing will continue to shape U.S. market access. Suppliers that can clearly document the R&D-exempt basis for shipment, or that can support a PMN pathway for larger volumes, will be better positioned as U.S. programmes advance beyond research scale.
For Russian and EAEU buyers, the strategic implication is that procurement should be treated as a specification-and-documentation decision rather than a price comparison. A nominal 95% lot that fails to meet the programme’s purity requirement, or a shipment that arrives without a Russian-language SDS and lot-specific analytical data, can cost more in lost synthesis time than the price difference between two suppliers. The lowest-risk source is the one that can provide lot-specific HPLC data, confirm the 5-methyl-4-carboxy substitution pattern, clarify TSCA status for U.S.-linked programmes, and support the programme as it scales.
Shanghai XinChem Co., Ltd. (XinChem)
As a world-leading supplier of organic chemicals, Shanghai XinChem Co., Ltd. (XinChem) offers 5-methyl-1,3-oxazole-4-carboxylic acid (CAS 103879-58-9) in research-grade and custom-synthesis specifications, serving medicinal chemistry groups, antibacterial and kinase inhibitor discovery programmes, CNS drug discovery teams and pharmaceutical process development organisations. Our material is supplied with lot-specific analytical data, controlled purity and the documentation support that oxazole building-block qualification requires at both catalogue and scale-up stages.
Technical and Quality Advantages
Lot-Specific HPLC Data and Substitution-Pattern Confirmation: 5-Methyl-1,3-oxazole-4-carboxylic acid is supplied with a Certificate of Analysis reporting identity and purity by HPLC for the specific lot, with the 5-methyl-4-carboxy substitution pattern confirmed. Because the position of the methyl and carboxyl groups determines pKa, LogP and reactivity, lot-level confirmation is more informative than a catalogue percentage, and it allows the medicinal chemist to qualify the material against the programme’s actual requirements.
Purity at ≥95% and ≥98% Thresholds with Grade Distinction: Material is available at ≥95% (HPLC), consistent with the standard research-grade specification, with ≥98% grades available for applications where a tighter impurity profile is required. The explicit grade distinction allows the buyer to match the specification to the stage of development rather than discovering after purchase that a nominal-grade lot requires additional purification.
TSCA Status Clarity: XinChem provides a direct, lot-specific statement of the current TSCA inventory position, rather than relying on an inconsistent catalogue field. For U.S.-facing programmes, this clarity supports the buyer’s assessment of whether an R&D-exempt pathway or a PMN is required for the intended use.
Custom Synthesis and Scale-Up Continuity: The compound is available from 250 mg and 1 g qualification quantities through to custom-synthesis gram and tens-of-gram volumes, with the analytical method and impurity profile held constant across scales. This continuity reduces the re-qualification burden when a programme advances from medicinal chemistry to process development.
Regulatory and Language Support: Safety data sheets are available in English and Russian, with documentation covering the GHS07 irritant classification (H302, H315, H319, H335) and the recommended storage conditions (0–8 °C or 2–8 °C, dry, sealed). For EAEU buyers, the Russian-language SDS and Certificate of Analysis support incoming qualification.
Packaging and Logistics Flexibility
5-Methyl-1,3-oxazole-4-carboxylic acid is available in sealed 250 mg, 1 g, 5 g, 10 g and 25 g containers for research and medicinal chemistry use, with 100 g and larger package sizes for custom-synthesis and process-development quantities. The product should be stored at 0–8 °C or 2–8 °C in a dry, tightly sealed container protected from moisture. For Russia and EAEU destinations, XinChem arranges logistics with appropriate customs and transport documentation, including Russian-language SDS and Certificate-of-Analysis support, to reduce clearance friction for a building block that is sourced internationally at research scale.
Application Support and Supply Reliability
XinChem’s technical team assists with grade selection for hinduchelin antibacterial programmes, kinase inhibitor and CNS lead optimisation, amide-bond and esterification strategy for the C4 carboxylic acid, and with the analytical and documentation requirements that oxazole building-block qualification demands. Supply schedules accommodate both catalogue-scale qualification orders and custom-synthesis volumes, with stock held for the package sizes most commonly requested in medicinal chemistry programmes.
Why Choose XinChem
Expertise: Deep experience in oxazole and heteroaromatic carboxylic acid building blocks, with application knowledge spanning antibacterial discovery, kinase inhibitor programmes and CNS drug leads.
Consistency: Lot-specific control of identity, HPLC purity and substitution pattern—the parameters that determine whether 5-methyl-1,3-oxazole-4-carboxylic acid incorporates cleanly into a target molecule or introduces a purification burden.
Compliance Readiness: Documentation structured around the GHS07 irritant classification, the current TSCA non-listing status and EAEU documentation expectations, with Russian-language SDS support.
Responsiveness: Direct technical and commercial access, with order structures from 250 mg qualification quantities to custom-synthesis volumes.
Contact us now to discuss your 5-methyl-1,3-oxazole-4-carboxylic acid requirements and request a specification sheet or qualification sample.
Website: www.xinchem.com
Email: sales1@xinchem.com
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Post time: Nov-01-2026