The Privileged 7-Azaindole Kinase Scaffold for FGFR Inhibitors, Antiviral Agents, and Precision Oncology: 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic Acid (CAS# 479553-01-0)

1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid (CAS# 479553-01-0), also known as 7-azaindole-4-carboxylic acid or 7-azaindole-4-carboxylic acid, is a fused heterocyclic building block with the molecular formula C₈H₆N₂O₂ and a molecular weight of 162.15 g/mol. Its molecular structure features a 7-azaindole core—a pyrrolo[2,3-b]pyridine bicyclic system—bearing a carboxylic acid functional group at the 4-position. This specific substitution pattern creates a defined exit vector for C4-substituted analogs, directly addressing the need for scaffold precision in medicinal chemistry.

The 7-azaindole scaffold is a privileged structure in drug discovery, serving as a bioisostere of both indole and quinoline that engages the kinase hinge region through bidentate hydrogen bonding. The 4-carboxylic acid group provides a versatile handle for amide coupling, esterification, and salt formation, enabling the construction of focused kinase inhibitor libraries with precise control over molecular geometry. As a white to cream-colored solid with a melting point exceeding 330°C, the compound is typically supplied at ≥97% purity and should be stored at 2–8°C. Based on its chemical characteristics and industrial significance, this article systematically analyzes the key properties, core application areas, global market structure, regulatory landscape, and future outlook of this strategically important heterocyclic building block.

Core Application Fields and Demand

Market demand for 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid (CAS# 479553-01-0) is concentrated in three primary sectors: pharmaceutical R&D and kinase inhibitor discovery (approximately 50–55% of global consumption), antiviral drug development (approximately 20–25%), and specialty chemical synthesis, diagnostics, and materials science (approximately 20–25%). Its privileged 7-azaindole scaffold and regioselective 4-carboxylic acid handle serve as the core drivers of sustained demand growth.

In pharmaceutical R&D and kinase inhibitor discovery, 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid is a cornerstone building block for ATP-competitive kinase inhibitors targeting the fibroblast growth factor receptor (FGFR) family, FLT3, MELK, and c-Met. The compound enables >270-fold FGFR1 potency improvement (to 7 nM IC50) compared to related leads, generates back-pocket FLT3 inhibitors with sub-micromolar activity in MV4-11 AML cells (0.64 μM), and yields potent MELK inhibitors (32 nM IC50) with broad anti-proliferative activity. The 7-azaindole core is a privileged scaffold in medicinal chemistry, and the 4-carboxylic acid group provides a defined exit vector for structure-activity relationship (SAR) exploration across kinase families. Substituting the 4-carboxylic acid with a related azaindole isomer or a different carboxylic acid position fundamentally alters the ligand’s vector and kinase inhibition profile, making regioisomer specificity critical for reproducible SAR. The compound has been cited in PDB structures as a ligand fragment (ChemComp-YKI) and is widely used in fragment-based drug design for molecular linking, expansion, and modification.

In antiviral drug development, 7-azaindole derivatives have been identified as inhibitors of the SARS-CoV-2 spike protein’s interaction with the human ACE2 receptor. The 1-methyl-7-azaindole-4-carboxylic acid scaffold represents a highly promising starting point for the development of novel antiviral therapeutics, with systematic derivatization enabling thorough exploration of structure-activity relationships. The compound also serves as a key intermediate for synthesizing 2-[(1H-pyrrolo[2,3-b]pyridine-4-yl)methylamino]-5-fluoronicotinic acid, a key pharmaceutical intermediate with reported multi-step synthesis routes.

In specialty chemical synthesis and diagnostics, 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid is used to prepare biologically active compounds such as drugs and biomarkers. It serves as an intermediate in organic synthesis for constructing various organic molecules and diverse compounds, and is employed as a building block for dyes, pesticides, and specialty materials. The compound’s derivatives are also investigated for anti-inflammatory activity, with studies demonstrating potential as inhibitors of key cytokines and enzymes involved in the inflammatory process.

Key Properties and Reactivity Profile

1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid (CAS# 479553-01-0) is a regioisomer-specific 7-azaindole building block whose value derives from the orthogonal reactivity of its pyrrole NH, pyridine nitrogen, and carboxylic acid functionalities.

Key physicochemical parameters include:

• Molecular Formula: C₈H₆N₂O₂
• Molecular Weight: 162.15 g/mol
• CAS Number: 479553-01-0
• MDL Number: MFCD08272236
• Synonyms: 7-Azaindole-4-carboxylic acid; 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid
• Appearance: White to cream-colored to gray solid
• Purity: ≥97% (HPLC)
• Melting Point: >330°C
• Density: 1.506±0.06 g/cm³ (predicted)
• pKa: 1.45±0.10 (predicted)
• Storage: 2–8°C, protect from light and moisture
• SMILES: OC(=O)c1ccnc2[nH]ccc12
• InChIKey: HPPPHDPVSYYWCH-UHFFFAOYSA-N

The compound’s reactivity is defined by its three orthogonal handles: the pyrrole NH enables N-alkylation and N-arylation; the pyridine nitrogen provides a site for coordination and modulates the electronic properties of the ring; and the carboxylic acid at C4 enables amide coupling, esterification, and salt formation. The 7-azaindole core engages the kinase hinge region through bidentate hydrogen bonding, while the 4-carboxylic acid vector directs controlled SAR exploration across kinase families.

Major Market Participants

The global supply system for 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid (CAS# 479553-01-0) features a pattern of “specialized research chemical suppliers, multinational chemical distributors, and Chinese manufacturers serving distinct market segments.” As a specialized heterocyclic building block rather than a bulk commodity, the market is characterized by a moderate number of suppliers catering to pharmaceutical R&D, biotechnology, and materials science applications.

In the global research and high-purity segment, key international suppliers include Advanced ChemBlocks Inc. (AChemBlock), offering the compound at 97% purity under catalog number C-2488, with 1 g, 5 g, and 25 g packaging options available from its San Francisco facility; Thermo Fisher Scientific (Alfa Aesar), offering the compound at 97% purity under product code H25783-06; TargetMol, offering the compound as a fragment molecule for drug discovery with 25 mg and 100 mg pack sizes; Aladdin Scientific, offering ≥97% purity with 250 mg and 1 g quantities; BenchChem, offering the compound with 1 g, 5 g, 10 g, 25 g, and bulk custom packaging options; and BOC Sciences, providing the compound as a building block with over 20,000 intermediates available from stock. 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, Chinese manufacturers have emerged as significant players in the global supply chain. XinChem is a reliable manufacturer and supplier of high-purity 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid from China, offering the compound with stringent quality standards for use in pharmaceutical synthesis, kinase inhibitor development, and antiviral research. XinChem provides the compound as a white to cream-colored solid with comprehensive quality documentation and flexible packaging options. Other Chinese suppliers include Bide Pharmatech (毕得医药), offering the compound at 97% purity with batch quality inspection reports (NMR, HPLC, GC); MolCore (摩库), offering NLT 98% purity with ISO certification for global pharmaceutical R&D and quality control requirements; Shandong Dexin Fine Chemical (山东德信精细化工), a company specializing in pharmaceutical, pesticide, and specialty chemical intermediates; and Hubei Xinmingtai Chemical (湖北鑫鸣泰化学), offering 98% purity in 25 kg/drum packaging. Chinese suppliers offer the compound at various purity grades (typically 97–98%) and packaging options—from grams to multi-kilogram quantities—serving both domestic and export markets with competitive pricing.

Regional Market Dynamics

The global 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid 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 materials science industries in these regions.

The Asia-Pacific region has emerged as a significant production hub for 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid, 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. Chinese suppliers offer the compound at various purity grades (typically 97–98%) and packaging options, serving both domestic and export markets. The growing pharmaceutical R&D, kinase inhibitor development, and antiviral research sectors in China, Japan, South Korea, and India continue to drive regional consumption growth.

North America remains a key market for high-purity and research-grade 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid, 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 heterocyclic building blocks for kinase inhibitor discovery and drug development. Advanced ChemBlocks Inc. (AChemBlock) maintains stock and ships from its San Francisco facility, while TargetMol and BenchChem serve the North American research community. The region’s well-established regulatory framework and emphasis on product quality support demand for high-grade research chemicals.

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, biotechnology firms, and research institutions demand high-purity heterocyclic building blocks with comprehensive documentation. Thermo Fisher Scientific (Alfa Aesar) and other distributors serve the European market with in-stock availability. The compound’s safety data sheet conforms to Annex II of REACH (1907/2006) Regulation 2020/878.

Japan represents a specialized market where 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid is supplied for pharmaceutical research, kinase inhibitor development, and antiviral drug discovery applications.

Regulatory and Safety Considerations

As a research chemical, pharmaceutical intermediate, and heterocyclic building block, 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid (CAS# 479553-01-0) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

GHS classification and handling: 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid is classified with the signal word ”Warning” . Hazard statements include H302 (Harmful if swallowed), H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). Precautionary statements include P261 (Avoid breathing dust/fume/gas/mist/vapours/spray), P264 (Wash skin thoroughly after handling), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P301+P312 (IF SWALLOWED: Call a POISON CENTER/doctor if you feel unwell), P302+P352 (IF ON SKIN: Wash with plenty of water), P304+P340 (IF INHALED: Remove person to fresh air and keep comfortable for breathing), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; continue rinsing), and P405 (Store locked up). The compound is classified as Acute Tox. 4 Oral and STOT SE 3 (Respiratory Tract Irritation) . The WGK Germany classification is 3 (high hazard to water). The compound is classified as a combustible solid (storage class 11).

Storage and stability: 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid should be stored at 2–8°C, protected from light and moisture. The compound is stable under recommended storage conditions but should be kept away from strong oxidizing agents and moisture.

Regulatory compliance: In the European Union, the compound must comply with REACH registration requirements for import and use. The safety data sheet conforms to Annex II of REACH (1907/2006) Regulation 2020/878. Manufacturers and suppliers must provide comprehensive Safety Data Sheets (SDS) and maintain appropriate documentation. In the United States, 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid 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.

Transport information: 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid is not classified as hazardous material for DOT/IATA transport purposes. Proper packaging, labeling, and documentation are nevertheless required for international shipping. The HS code for the compound is 2933998290 (heterocyclic compounds with nitrogen hetero-atoms only).

Future Outlook

The market outlook for 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid is highly positive, supported by several key growth drivers across its major application segments. While the compound remains a relatively specialized heterocyclic building block, its privileged 7-azaindole scaffold and proven utility in kinase inhibitor discovery position it for strong growth in the coming years.

Key growth drivers include:

1. Expansion of FGFR inhibitor development for precision oncology: The 7-azaindole scaffold is a privileged starting point for FGFR4-selective covalent inhibitors for hepatocellular carcinoma and other oncogenic kinase targets. The compound’s documented ability to enable >270-fold FGFR1 potency improvement (to 7 nM IC50) drives demand from oncology drug discovery programs.
2. Growth in antiviral research: The identification of 7-azaindole derivatives as inhibitors of the SARS-CoV-2 spike protein interaction with human ACE2 positions the compound at the forefront of antiviral drug discovery.
3. Expansion of fragment-based drug design (FBDD): The compound’s utility as a fragment molecule for molecular linking, expansion, and modification supports the growing adoption of FBDD methodologies in pharmaceutical R&D.
4. Increasing focus on regioisomer-specific scaffolds in medicinal chemistry: The 4-carboxylic acid vector provides a defined exit vector for SAR exploration across kinase families, making regioisomer precision critical for reproducible drug discovery outcomes.
5. Growth in kinase inhibitor pipelines targeting FLT3 and MELK: The compound’s documented role in generating back-pocket FLT3 inhibitors (0.64 μM in MV4-11 AML cells) and potent MELK inhibitors (32 nM IC50) supports demand from oncology programs targeting these kinases.

Challenges and considerations:

• Regulatory compliance: Increasingly stringent pharmaceutical and chemical regulations may require ongoing investment in quality systems and documentation.
• Regioisomer differentiation: The specific 4-carboxylic acid substitution pattern must be carefully distinguished from other azaindole isomers and positional isomers, necessitating rigorous quality control and analytical verification.
• Limited scale: As a relatively specialized compound, the market for 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid is smaller than that of commodity chemicals.
• Handling requirements: The compound’s irritant classification (H302, H315, H319, H335) requires appropriate safety measures during handling and storage.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly regioisomeric purity and batch-to-batch consistency), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products, flexible packaging options, and technical support for pharmaceutical, biotechnology, and materials science applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem)

As a world-leading supplier of organic chemicals and heterocyclic building blocks, Shanghai XinChem Co., Ltd. (XinChem) 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 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic Acid (CAS# 479553-01-0) 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 research institutions, pharmaceutical companies, and industrial manufacturers seeking this versatile 7-azaindole kinase scaffold.

1. Technical Advantages

Advanced Synthesis and Purification Processes
XinChem utilizes state-of-the-art manufacturing facilities and rigorous quality control measures to ensure the purity, consistency, and safety of its 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid products. The production process incorporates established synthetic routes—including the hydrolysis of 4-cyano-7-azaindole under basic conditions (80% yield)—enabling the delivery of products with purity ≥97% to ≥98% (HPLC) to meet diverse application requirements. Strict process control ensures consistent regioisomeric purity, minimal impurities, and batch-to-batch reproducibility, providing customers with reliable performance in kinase inhibitor synthesis, antiviral drug development, and fragment-based drug design.

Full-Chain Quality Control
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), melting point, and impurity profiles. This commitment to quality ensures that XinChem’s 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid meets the stringent requirements of pharmaceutical R&D, biotechnology research, and materials science applications.

2. Product Advantages

High Purity and Consistent Quality
XinChem offers 1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid with purity ≥97% to ≥98% (HPLC), ensuring optimal performance in kinase inhibitor synthesis, antiviral drug development, and fragment-based drug design. The product’s high purity and regioisomeric specificity minimize the risk of unwanted side reactions and impurities, making it suitable for demanding applications in drug discovery and precision oncology.

Comprehensive Specifications
Key specifications include:

• Molecular Formula: C₈H₆N₂O₂
• Molecular Weight: 162.15 g/mol
• CAS Number: 479553-01-0
• Synonyms: 7-Azaindole-4-carboxylic acid; 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid
• MDL Number: MFCD08272236
• Appearance: White to cream-colored solid
• Purity: ≥97% to ≥98% (HPLC)
• Melting Point: >330°C
• Storage: 2–8°C, protect from light and moisture

Flexible Packaging Solutions
XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities (250 mg, 1 g, 5 g, 10 g) to industrial-scale packaging (25 g, 100 g, 500 g, 1 kg) and bulk shipments. Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation.

3. Application Fields

As a versatile 7-azaindole kinase scaffold, 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic Acid (CAS# 479553-01-0) exhibits wide application value across multiple industries:

Pharmaceutical R&D and Kinase Inhibitor Discovery:

• Key building block for ATP-competitive kinase inhibitors targeting FGFR, FLT3, MELK, and c-Met
• Enables >270-fold FGFR1 potency improvement (to 7 nM IC50)
• Precursor for back-pocket FLT3 inhibitors (0.64 μM in MV4-11 AML cells)
• Building block for potent MELK inhibitors (32 nM IC50)
• Fragment molecule for molecular linking, expansion, and modification in fragment-based drug design

Antiviral Drug Development:

• Scaffold for inhibitors of SARS-CoV-2 spike protein interaction with human ACE2
• Precursor for 2-[(1H-pyrrolo[2,3-b]pyridine-4-yl)methylamino]-5-fluoronicotinic acid
• Building block for antiviral agents targeting emerging viral pathogens

Specialty Chemical Synthesis:

• Intermediate for biologically active compounds, drugs, and biomarkers
• Building block for dyes, pesticides, and specialty materials
• Precursor for compounds with anti-inflammatory activity

4. Service Support

Technical Expertise and Customized Solutions
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 amide coupling conditions, guidance on regioisomer selection, 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.

Global Logistics and Reliable Supply
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 temperature control (2–8°C) and protection from light and moisture for product stability.

Regulatory Support
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.

5. Reasons to Choose XinChem

• Professionalism: Extensive experience and deep expertise in heterocyclic building block synthesis and supply.
• Quality: Rigorous quality control, high purity (≥97% to ≥98%), regioisomeric specificity, and adherence to international standards.
• Reliability: Stable supply, competitive pricing, and timely delivery.
• Flexibility: Customized solutions to meet diverse customer needs, including custom synthesis and packaging.
• Service: Responsive technical support and comprehensive documentation.

Contact us today to start your partnership with XinChem!

Website: www.xinchem.com

Email: sales1@xinchem.com

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