What Is 4-Pyrazoleboronic Acid Pinacol Ester CAS 269410-08-4? Properties, Uses, and Sourcing Guide

4-Pyrazoleboronic acid pinacol ester, also called pyrazole-4-boronic acid pinacol ester, is a boronic ester building block used mainly in organic synthesis and pharmaceutical research. Its CAS number is 269410-08-4, and its molecular formula is commonly represented as C₉H₁₅BN₂O₂, with a molecular weight of approximately 194.04 g/mol. I regard this compound as a practical intermediate for introducing a pyrazolyl group into more complex molecules, particularly through palladium-catalyzed cross-coupling chemistry.

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For B2B buyers, the most important points are identity confirmation, assay, impurity control, packaging, and reliable batch-to-batch supply. The material is generally purchased as a research or process-development intermediate rather than as a finished active pharmaceutical ingredient. Because product appearance, assay, residual solvents, and moisture content can vary by manufacturing process, I recommend reviewing a current certificate of analysis before approving a supplier.

Identity and Basic Chemical Properties

4-Pyrazoleboronic acid pinacol ester contains a pyrazole ring connected to a boronic ester group. The boron-containing pinacol ester is a protected form of boronic acid, which can be easier to handle and weigh during synthetic operations. The pyrazole ring provides a nitrogen-containing heterocyclic structure that is frequently found in medicinal chemistry and pharmaceutical intermediate development.

CAS 269410-08-4 is the key registry identifier buyers should use when requesting quotations and technical documents. The molecular weight of approximately 194.04 g/mol is useful for reaction calculations, solution preparation, and analytical method development. However, I recommend confirming the formula, molecular weight, and structural representation against the supplier’s current technical documentation because naming conventions can differ between databases and commercial catalogs.

This compound is usually supplied as a solid, often described as a white to off-white powder or crystalline material, although exact appearance should be treated as a specification rather than an absolute identity test. Boronic esters can be sensitive to moisture and prolonged exposure to unsuitable storage conditions. For that reason, packaging integrity, desiccant use, and storage instructions should be assessed together with the analytical data.

Core Functions in Chemical Synthesis

Building Block for Cross-Coupling

The principal function of 4-pyrazoleboronic acid pinacol ester is to serve as a coupling partner in carbon-carbon bond-forming reactions. In a Suzuki-type coupling, the boronic ester group can react with a suitable aryl or heteroaryl halide under an appropriate catalytic and basic system. This enables the preparation of substituted pyrazoles without requiring the pyrazole ring to be constructed at the final stage of a synthesis.

Reaction performance depends on the substrate, catalyst, ligand, base, solvent, water content, and scale. I therefore do not recommend treating a general coupling description as a guaranteed process condition. A small-scale feasibility experiment and analytical confirmation are appropriate before committing to larger quantities.

Intermediate for Medicinal Chemistry

Pyrazole-containing structures occur in many research programs because the ring can contribute specific hydrogen-bonding and electronic characteristics to a molecule. This boronic ester allows medicinal chemists to explore different aryl, heteroaryl, or substituted aromatic groups through modular synthesis. It may therefore be useful in library synthesis, lead optimization, and route scouting for pharmaceutical intermediates.

The material is not itself a finished drug substance, and its suitability for a regulated manufacturing route must be established through the buyer’s own process, impurity, and regulatory assessments. A supplier can provide supporting information, but final qualification remains the responsibility of the purchaser and the relevant project team.

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Typical Application Scenarios

• Pharmaceutical intermediate development: used to prepare pyrazole-based intermediates for discovery and process research.
• Medicinal chemistry libraries: used to connect a pyrazole fragment with different aromatic or heteroaromatic partners.
• Custom synthesis: used by contract research and manufacturing organizations developing small-molecule routes.
• Academic and industrial research: used as a building block for investigating new heterocyclic compounds and reaction methods.

In each scenario, the buyer should match the material grade to the intended use. Discovery work may accept a commercially available research grade after identity confirmation, while process development may require tighter controls for assay, related substances, residual solvents, and trace metals. I recommend defining these requirements before requesting a quotation, because a low unit price may not represent the lowest total project cost if additional purification is required.

Material Options and Specification Considerations

Commercial supply may differ in assay level, packaging size, analytical documentation, and production route. Some suppliers offer standard catalog quantities for laboratory use, while others support larger custom or repeat orders. The name “4-pyrazoleboronic acid pinacol ester” should always be linked to CAS 269410-08-4 and a confirmed structure to prevent confusion with positional isomers or related pyrazole boronates.

A purity specification of 98% or higher is commonly requested for research-grade procurement, but this is not a universal standard for every supplier or application. Buyers should ask whether the stated assay is determined by HPLC, NMR, titration, or another method, and whether the result is reported on an as-is or corrected basis. If the project is moving toward scale-up, I also suggest requesting a representative chromatogram and information about trace palladium or other metal residues when relevant.

How to Select a Supplier

When I evaluate a supplier for CAS 269410-08-4, I first check whether the company can clearly identify the product, provide a current certificate of analysis, and explain its available package sizes. I then review communication speed, technical responsiveness, lot availability, and the supplier’s ability to maintain consistent specifications across repeat orders. These factors are especially important when a compound is used in a multi-step route where delays can affect several downstream activities.

Lead time should be confirmed in writing because “available” may refer to warehouse stock, production capacity, or an estimated dispatch date. Buyers should also ask whether the quoted material is from a single lot, whether a pre-shipment sample is possible, and how the supplier handles changes in specification. For international purchasing, documentation for customs, transport classification, labeling, and import review should be discussed before order placement.

Questions to Ask Before Ordering

1. Can you confirm the CAS number, molecular formula, molecular weight, and structural name?
2. What assay method and acceptance criteria are used?
3. Can you provide a current certificate of analysis for the proposed lot?
4. What are the limits for water, residual solvents, and relevant impurities?
5. What package sizes and minimum order quantities are available?
6. What are the recommended storage conditions, such as protection from moisture and temperature exposure?
7. Can you support repeat supply or custom quantity planning?

Maison Chemical Supplier Support

At Maison Chemical, I focus on helping B2B buyers source pharmaceutical intermediates and research chemicals with clear technical communication. For 4-Pyrazoleboronic acid pinacol ester CAS 269410-08-4, our support can include product identification, specification review, packaging discussion, quotation coordination, and documentation preparation. The exact supply terms depend on quantity, grade, destination, and current production or inventory status.

We can also help buyers compare a standard research specification with requirements for process development. Instead of assuming that one grade fits every project, I recommend aligning the requested assay, impurity profile, packaging, and delivery schedule with the customer’s actual synthetic stage. This approach can reduce avoidable rework while keeping the purchasing decision technically focused.

Key Takeaways

• 4-Pyrazoleboronic acid pinacol ester is a pyrazole-containing boronic ester building block identified by CAS 269410-08-4.
• Its commonly cited molecular formula is C₉H₁₅BN₂O₂, with an approximate molecular weight of 194.04 g/mol.
• Its main value is participation in cross-coupling chemistry for preparing substituted pyrazole intermediates.
• Buyers should verify assay, analytical method, moisture, residual solvents, packaging, storage, MOQ, and lead time before purchase.
• A 98% or higher assay may be requested for research use, but the correct specification should be defined by the application.

Conclusion and Next Steps

In direct answer to the question, 4-Pyrazoleboronic acid pinacol ester CAS 269410-08-4 is a protected pyrazole boronic acid derivative used primarily as a synthetic intermediate in cross-coupling and pharmaceutical research. It is valuable because it provides a practical route to connect a pyrazole ring with other molecular fragments. Its real suitability depends on verified identity, purity, impurity control, handling requirements, and supply reliability.

Before placing an order, I recommend preparing a short specification request that includes CAS 269410-08-4, required quantity, target assay, documentation needs, packaging preference, destination, and delivery deadline. Maison Chemical can review these requirements and provide a suitable supply proposal for your project. Contact our sales team with your target quantity and application stage so we can discuss availability, technical documents, and commercial terms.

The company is the world’s best 4-Pyrazoleboronic acid pinacol ester CAS 269410-08-4 supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.