Tautomer-Defined Pyridinone Scaffold for p38 Kinase Inhibitors, Favipiravir Analog Synthesis, and Biomass-Derived Nitrogen Heterocycles: 6-Methylpyridine-2,4-diol CAS# 3749-51-7

6-Methylpyridine-2,4-diol (CAS# 3749-51-7), also known as 4-hydroxy-6-methyl-2(1H)-pyridinone, 4-hydroxy-6-methyl-1H-pyridin-2-one, 2,4-dihydroxy-6-methylpyridine, 4,6-dihydroxy-2-picoline, or NSC 110283, is a hydroxypyridinone heterocyclic compound with the molecular formula C₆H₇NO₂ and a molecular weight of 125.13 g/mol. Its molecular structure features a pyridine ring bearing hydroxyl groups at the 2- and 4-positions and a methyl group at the 6-position—a substitution pattern that determines its dominant tautomeric form as 4-hydroxy-6-methyl-2(1H)-pyridinone. The compound appears as a beige to pale brown or grey crystalline powder with a melting point of 324–330°C, excellent thermal stability (>320°C), a predicted pKa of approximately 4.50, and a UV λmax of 282 nm in ethanol. It is commercially available at ≥97–98% purity (HPLC/GC) and should be stored at room temperature in a dry, well-sealed container.

The defining feature of 6-methylpyridine-2,4-diol is its defined tautomeric preference for the 4-hydroxy-2-pyridinone form. This specific electronic and steric arrangement—hydroxyls at the 2,4-positions and a methyl group at the 6-position—is crucial for its role as an isomer-specific intermediate in synthesizing bioactive molecules such as p38 kinase inhibitors. Substituting a closely related isomer like 2,6-dihydroxy-4-methylpyridine would fundamentally change the regiochemistry of subsequent reactions, likely leading to a different product profile and potentially nullifying the desired biological activity. This tautomer-defined regioselectivity, combined with exceptional thermal stability that enables high-temperature synthetic steps not feasible with lower-melting isomers, positions 6-methylpyridine-2,4-diol as a strategically important building block in modern medicinal chemistry, pharmaceutical development, and biomass-derived nitrogen heterocycle synthesis.

Market demand for 6-methylpyridine-2,4-diol (CAS# 3749-51-7) is concentrated in four primary sectors: pharmaceutical R&D and p38 kinase inhibitor synthesis (approximately 40–45% of global consumption), antimicrobial and antifungal analog development (approximately 20–25%), biomass-derived nitrogen heterocycle synthesis (approximately 15–20%), and analytical reference standards and specialty chemical applications (approximately 10–15%). Its tautomer-defined regioselectivity and exceptional thermal stability serve as the core drivers of sustained demand growth.

In pharmaceutical R&D and p38 kinase inhibitor synthesis, 6-methylpyridine-2,4-diol is a key starting material for the synthesis of p38 kinase inhibitors—a class of compounds investigated for treating inflammatory diseases. p38 mitogen-activated protein kinases are central to the biosynthesis of pro-inflammatory cytokines such as TNF-α and IL-1β, making their inhibition a validated strategy for rheumatoid arthritis, psoriasis, and other inflammatory conditions. The compound's defined tautomeric preference for the 4-hydroxy-2-pyridinone form ensures regioselective functionalization in cyclocondensation and cross-coupling reactions, enabling reproducible synthesis of p38 inhibitor intermediates. The compound serves as a critical building block for constructing pyridinone-based drug discovery libraries, supporting hit-to-lead and lead optimization campaigns targeting inflammatory pathways.

In antimicrobial and antifungal analog development, 6-methylpyridine-2,4-diol is used to synthesize analogs of Favipiravir (T-705), a broad-spectrum antiviral prodrug effective against RNA viruses including influenza, arenaviruses, and SARS-CoV-2. The pyridinone scaffold of 6-methylpyridine-2,4-diol enables the construction of Favipiravir analogs with modified pharmacokinetic and antiviral properties, supporting the development of next-generation antiviral therapeutics. The compound's derivatives also demonstrate antimicrobial and fungicidal activities, making it valuable for developing novel anti-infective agents.

In biomass-derived nitrogen heterocycle synthesis, 6-methylpyridine-2,4-diol serves as a gateway intermediate for renewable 2-methylpiperidine (76.5% yield) and 6-methylpiperidin-2-one (78.5% yield) production. These biomass-derived nitrogen heterocycles represent sustainable alternatives to petrochemical feedstocks for pharmaceutical, agrochemical, and specialty chemical manufacturing. The compound is also employed in the synthesis of 4-pyridinyl-4H-chromenes for hit-to-lead libraries, delivering 82–99% yields in 5-minute domino syntheses. Its well-characterized iron(III) complexes—[Fe(4H6M2P)₃(SCN)₃]—are studied for antimicrobial coordination chemistry applications.

In analytical reference standards and specialty chemical applications, 6-methylpyridine-2,4-diol is suitable as a reference material for analytical method development, calibration, and quality control. It is used as a high-purity building block in organic synthesis and product development across research and industrial settings, and as a ligand in coordination chemistry and catalysis.

6-Methylpyridine-2,4-diol (CAS# 3749-51-7) is a tautomer-defined hydroxypyridinone whose value derives from the orthogonal reactivity of its 2-pyridone carbonyl, 4-hydroxyl, and 6-methyl substituents.

Key physicochemical parameters include:

The compound's reactivity is defined by its tautomer-specific handles: the 2-pyridone carbonyl provides a site for nucleophilic addition, condensation, and metal coordination; the 4-hydroxyl group enables etherification, esterification, and hydrogen bonding; and the 6-methyl group modulates the electronic properties of the ring and provides steric control over reaction regioselectivity. The defined tautomeric preference for the 4-hydroxy-2-pyridinone form ensures predictable reactivity in cyclocondensation and cross-coupling reactions—a critical requirement for reproducible synthesis of bioactive molecules. The compound forms stable metal complexes through bidentate coordination involving the pyridone carbonyl and the adjacent hydroxyl group.

The global supply system for 6-methylpyridine-2,4-diol (CAS# 3749-51-7) features a pattern of specialized heterocyclic building block manufacturers, multinational research chemical distributors, and Chinese producers serving distinct market segments. As a specialized tautomer-defined pyridinone scaffold rather than a bulk commodity, the market is characterized by a moderate number of suppliers catering to pharmaceutical R&D, medicinal chemistry, and academic research.

In the global research and high-purity segment, key international suppliers include Fluorochem (UK), offering the compound at 95% purity under product code F068449, with in-stock availability in the UK, Germany, and China. AK Scientific (AKSci) offers the compound at 98% (HPLC) purity under product code Y8909, with 5 g, 25 g, and 100 g IN STOCK from the SF Bay Area, California. Thermo Fisher Scientific (Acros Organics) offers the compound at 97% purity (96% min. by HPLC) under catalog number AAA15439-06 and -14, with specifications including beige powder appearance. Tokyo Chemical Industry (TCI) offers the compound at >98.0% (GC)(T) purity under product code D4361. Apollo Scientific (UK) offers the compound at 98% purity by HPLC under catalog number AS476241, with grey to faint brown solid appearance and 1H-NMR confirmation. Combi-Blocks offers the compound under product code SS-6632 with room-temperature storage. BOC Sciences offers the compound under catalog number 3749-51-7 as 4-hydroxy-6-methyl-2-pyridinone. CymitQuimica offers the compound at 98% purity by HPLC with grey to faint brown solid appearance. VWR International offers the compound at 97% purity with HPLC ≥96.0% specification. These suppliers serve the pharmaceutical, biotechnology, and academic research communities with products that meet rigorous quality specifications.

In the industrial and large-scale production segment, XinChem is a reliable manufacturer and supplier of high-purity 6-methylpyridine-2,4-diol from China, offering the compound with stringent quality standards for use in p38 kinase inhibitor synthesis, Favipiravir analog development, and biomass-derived nitrogen heterocycle production. XinChem provides the compound as a beige to pale brown crystalline powder with comprehensive quality documentation, batch-specific Certificates of Analysis (COA) including HPLC and 1H-NMR data, customizable packaging, and globally compliant REACH, ISO 9001, and GMP-aligned manufacturing. The company emphasizes that 6-methylpyridine-2,4-diol is a critical building block with a defined tautomeric preference essential for regioselective synthesis, serving as a key starting material for p38 kinase inhibitors and Favipiravir analogs. Additional suppliers in the region offer the compound at various purity grades (typically 95–99%) and packaging options—from 250 mg to 2.5 kg—serving both domestic and export markets.

The global 6-methylpyridine-2,4-diol market exhibits distinct regional characteristics, with production concentrated in Asia-Pacific (particularly China) and consumption distributed across North America, Europe, and the Asia-Pacific region, aligned with the pharmaceutical, biotechnology, and academic research industries in these regions.

The Asia-Pacific region has emerged as a significant production hub for 6-methylpyridine-2,4-diol, with China hosting numerous manufacturers and suppliers including XinChem. The region's competitive advantages include lower production costs, established chemical infrastructure, and proximity to rapidly growing pharmaceutical and biotechnology industries. Suppliers in the region offer the compound at various purity grades (typically 95–99%) and packaging options, serving both domestic and export markets. The growing pharmaceutical R&D, p38 kinase inhibitor development, and antiviral drug discovery sectors in China, India, Japan, and South Korea continue to drive regional consumption growth. The compound is classified as a pharmaceutical intermediate and fine chemical building block in the Chinese market, with multiple suppliers offering the product in packaging sizes ranging from 250 mg to 2.5 kg.

North America remains a key market for high-purity and research-grade 6-methylpyridine-2,4-diol, driven by demand from the pharmaceutical industry, biotechnology companies, and academic research institutions. The United States hosts numerous research organizations, pharmaceutical companies, and contract research organizations that require high-quality tautomer-defined pyridinone scaffolds for p38 kinase inhibitor discovery, Favipiravir analog development, and biomass-derived heterocycle synthesis. AK Scientific, Thermo Fisher Scientific, BOC Sciences, and other international distributors serve the North American market with extensive distribution networks. The region's well-established regulatory framework, including FDA oversight of pharmaceutical R&D, supports demand for high-grade research chemicals and pharmaceutical intermediates.

Europe is characterized by stringent regulatory requirements, including REACH registration, and a strong focus on quality and sustainability in pharmaceutical and chemical research. European pharmaceutical companies, medicinal chemistry laboratories, and research institutions demand high-purity heterocyclic building blocks with comprehensive documentation. Fluorochem (UK), Thermo Fisher Scientific (Acros Organics), and Apollo Scientific (UK) serve the European market with in-stock availability. The compound is registered under REACH with EINECS number 690-441-0. The region's strong pharmaceutical and biotechnology sectors support steady demand for high-quality pyridinone derivatives.

Japan represents a specialized market where 6-methylpyridine-2,4-diol is supplied by Tokyo Chemical Industry (TCI) and other distributors for pharmaceutical research, kinase inhibitor development, and fine chemical applications.

As a hydroxypyridinone heterocyclic building block and pharmaceutical intermediate, 6-methylpyridine-2,4-diol (CAS# 3749-51-7) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

6-Methylpyridine-2,4-diol is classified with the signal word "Warning". Hazard statements include H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). The compound is classified as Skin Irrit. 2, Eye Irrit. 2, and STOT SE 3 (respiratory system). Precautionary phrases include P261 (Avoid breathing dust/fume/gas/mist/vapours/spray), P264 (Wash hands thoroughly after handling), P270 (Do not eat, drink or smoke when using this product), P271 (Use only outdoors or in a well-ventilated area), and P280 (Wear protective gloves/protective clothing and eye/face protection). The compound is classified as GHS07 – Harmful/Irritant. Personal protective equipment including lab gloves, safety glasses, and a lab coat should be worn during handling, and operations should be conducted in a well-ventilated environment or fume hood. The compound is a solid at room temperature and should be handled with care to avoid dust generation.

6-Methylpyridine-2,4-diol should be stored at room temperature in a tightly sealed container protected from moisture and light. The compound exhibits excellent thermal stability (>320°C) and is stable under recommended storage conditions. It should be kept away from strong oxidizing agents.

In the European Union, the compound must comply with REACH registration requirements for import and use. The compound has an EINECS number of 690-441-0 and an MDL number of MFCD01860849. Manufacturers and suppliers must provide comprehensive Safety Data Sheets (SDS) and maintain appropriate documentation. In the United States, 6-methylpyridine-2,4-diol is intended for research and development use only and is not intended for therapeutic, food, cosmetic, or consumer applications unless explicitly stated otherwise. For pharmaceutical intermediate applications, manufacturers must comply with relevant FDA regulations and quality standards. The compound is not a controlled substance.

6-Methylpyridine-2,4-diol is not classified as hazardous material for DOT/IATA transport purposes under standard conditions. Proper packaging, labeling, and documentation are required for international shipping. The compound is typically shipped at ambient temperature with appropriate protection from moisture and light.

The market outlook for 6-methylpyridine-2,4-diol is positive, supported by several key growth drivers across its major application segments. While the compound remains a relatively specialized tautomer-defined pyridinone scaffold, its essential role in p38 kinase inhibitor and Favipiravir analog development, combined with its utility in biomass-derived nitrogen heterocycle synthesis, positions it for steady growth in the coming years.

Key growth drivers include:

The continued development of p38 kinase inhibitors for inflammatory diseases—including rheumatoid arthritis, psoriasis, and chronic obstructive pulmonary disease—drives demand for tautomer-defined pyridinone scaffolds that ensure regioselective synthesis. The compound's defined tautomeric preference for the 4-hydroxy-2-pyridinone form is critical for reproducible synthesis of p38 inhibitor intermediates, supporting sustained demand from inflammation drug discovery programs.

The increasing global focus on antiviral drug discovery, particularly for RNA viruses including influenza, arenaviruses, and SARS-CoV-2, drives demand for 6-methylpyridine-2,4-diol as a key starting material for Favipiravir analog synthesis. The compound's pyridinone scaffold enables the construction of modified Favipiravir analogs with improved pharmacokinetic and antiviral properties.

The growing emphasis on renewable feedstocks and sustainable chemistry drives demand for 6-methylpyridine-2,4-diol as a gateway intermediate for renewable 2-methylpiperidine (76.5% yield) and 6-methylpiperidin-2-one (78.5% yield) production. These biomass-derived heterocycles represent sustainable alternatives to petrochemical feedstocks for pharmaceutical and specialty chemical manufacturing.

The growing recognition of the critical role of tautomeric preference in determining reaction regioselectivity and biological activity drives demand for 6-methylpyridine-2,4-diol as a tautomer-defined building block that cannot be substituted by closely related isomers without introducing quantifiable liabilities in regiochemistry and product profiles.

The compound's well-characterized iron(III) complexes—[Fe(4H6M2P)₃(SCN)₃]—are studied for antimicrobial coordination chemistry applications, supporting demand from academic and industrial research laboratories.

Challenges and considerations:

As a specialized tautomer-defined pyridinone scaffold, the market for 6-methylpyridine-2,4-diol is smaller than that of commodity chemicals.

The market faces competition from other hydroxypyridinone derivatives and heterocyclic building blocks with similar reactivity profiles. Substituting a closely related isomer like 2,6-dihydroxy-4-methylpyridine would fundamentally change the regiochemistry of subsequent reactions.

The compound's classification as an irritant (H315, H319, H335) requires appropriate safety measures during handling and storage.

Increasingly stringent pharmaceutical and chemical regulations may require ongoing investment in quality systems and documentation.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly tautomer consistency and batch-to-batch reproducibility), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products with comprehensive Certificates of Analysis (COA) including HPLC and 1H-NMR data, flexible packaging options, and technical support for pharmaceutical, medicinal chemistry, and biomass-derived heterocycle applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem) is a world-leading supplier of organic chemicals and heterocyclic building blocks. The company is dedicated to meeting the innovative needs of the pharmaceutical, biotechnology, and fine chemical industries. Leveraging extensive experience and advanced manufacturing capabilities, XinChem provides high-quality 6-Methylpyridine-2,4-diol (CAS# 3749-51-7) to customers worldwide.

As a trusted manufacturer and supplier based in China, XinChem combines competitive pricing, reliable supply, and exceptional service to establish itself as a preferred partner for pharmaceutical companies, medicinal chemistry researchers, and drug discovery institutions seeking this versatile tautomer-defined pyridinone scaffold.

XinChem utilizes state-of-the-art manufacturing facilities and rigorous quality control measures to ensure the purity, consistency, and tautomer integrity of its 6-methylpyridine-2,4-diol products. The production process incorporates established synthetic routes—including the hydrolysis of dehydroacetic acid to 4-hydroxy-6-methyl-2H-pyran-2-one followed by ammoniation to yield 4-hydroxy-6-methyl-2-pyridinone—enabling the delivery of products with purity ≥97% (HPLC/GC) and ≥98% (HPLC/GC) to meet diverse application requirements. Strict process control ensures consistent product quality, defined tautomeric preference (4-hydroxy-2-pyridinone form), minimal impurities, and batch-to-batch reproducibility, providing customers with reliable performance in p38 kinase inhibitor synthesis, Favipiravir analog development, and biomass-derived nitrogen heterocycle production.

The production process strictly adheres to international quality standards, with comprehensive quality control covering raw material sourcing, in-process monitoring, and finished product testing. Each batch is accompanied by a detailed Certificate of Analysis (COA) documenting physical and chemical properties, purity data (HPLC/GC), appearance, identity confirmation by 1H-NMR, and impurity profiles. XinChem offers batch-specific COA, customizable packaging, and globally compliant REACH, ISO 9001, and GMP-aligned manufacturing.

XinChem offers 6-methylpyridine-2,4-diol with purity ≥97% (HPLC/GC) and ≥98% (HPLC/GC) available, ensuring optimal performance in p38 kinase inhibitor synthesis, Favipiravir analog development, and biomass-derived nitrogen heterocycle production. The product's defined tautomeric preference for the 4-hydroxy-2-pyridinone form ensures regioselective synthesis outcomes, making it suitable for demanding applications in drug discovery and medicinal chemistry. The compound is supplied as a beige to pale brown crystalline powder with consistent appearance and defined melting point specifications (324–330°C).

Key specifications include:

XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities (1 g, 5 g, 25 g) to industrial-scale packaging (100 g, 500 g, 1 kg, 2.5 kg) and bulk shipments. Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation with appropriate protection from moisture and light.

As a tautomer-defined pyridinone scaffold, 6-Methylpyridine-2,4-diol (CAS# 3749-51-7) exhibits wide application value across multiple industries:

XinChem's team of experienced chemists and application engineers provides full technical support throughout the customer journey—from product selection and specification development to application guidance and troubleshooting. Whether customers require optimization of cyclocondensation conditions, guidance on tautomer-specific reactivity, or assistance with regulatory documentation, XinChem's technical experts are ready to help. Custom synthesis and contract manufacturing with flexible scaling from R&D to commercial quantities are available upon request.

With established supply chains serving markets across Europe, North America, Asia-Pacific, and beyond, XinChem ensures timely delivery and consistent product availability. The company's logistics team manages all aspects of international shipping, including customs clearance and documentation, with appropriate protection from moisture and light for product stability.

XinChem provides comprehensive documentation to support regulatory compliance, including Safety Data Sheets (SDS), Certificates of Analysis (COA), and other required certificates. The company stays current with evolving regulatory requirements in major markets, including REACH, TSCA, and other regional regulations, helping customers navigate the complexities of global trade.

Extensive experience and deep expertise in heterocyclic building block synthesis and supply.

Rigorous quality control, high purity (≥97% to ≥98%), tautomer consistency, and adherence to international standards.

Stable supply, competitive pricing, and timely delivery.

Customized solutions to meet diverse customer needs, including custom synthesis and packaging.

Responsive technical support and comprehensive documentation including batch-specific COA.

Contact us today to start your partnership with XinChem!

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