4-Tolylboronic Acid CAS 5720-05-8: A Buyer’s Guide to Specifications, COA, and Bulk Supply

4-Tolylboronic acid, CAS 5720-05-8, is an aromatic boronic acid used as a building block in organic synthesis, especially palladium-catalyzed cross-coupling chemistry. When I evaluate this material for a purchasing, R&D, or quality team, I recommend checking four points first: identity, assay and impurity data, documentation quality, and supply continuity. The commonly used molecular formula is C₇H₉BO₂, with a molecular weight of approximately 135.96 g/mol. The correct buying decision depends not only on price, but also on whether the supplied grade matches the intended reaction, analytical method, and production scale.

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Who This Guide Is For

This guide is intended for procurement specialists, process chemists, analytical scientists, quality managers, and technical buyers sourcing 4-Tolylboronic acid for laboratory or commercial development. It is also useful for companies comparing multiple chemical suppliers before requesting a quotation. Because specifications can differ by manufacturer and application, I recommend treating the information below as a purchasing framework rather than as a universal product specification.

For a new project, the buyer should define the required grade, estimated annual demand, packaging preference, delivery location, and documentation requirements before contacting suppliers. A small development order may prioritize fast sampling and analytical transparency, while a production program may prioritize batch consistency, supply planning, and change-control communication. Separating these requirements early helps prevent a low initial price from creating higher qualification or rework costs later.

Basic Product Context

4-Tolylboronic acid is also commonly described as 4-methylphenylboronic acid or p-tolylboronic acid. Its structure contains an aryl group bearing a methyl substituent and a boronic acid functional group, which makes it useful as an aryl partner in synthetic transformations. The CAS number 5720-05-8 should be used together with the chemical name and molecular formula when checking supplier documents, because names and abbreviations may vary between databases and internal systems.

In a typical coupling workflow, the boronic acid reacts with a suitable electrophilic partner under a selected catalytic and base system. Actual performance depends on the substrate, catalyst, solvent, water content, temperature, reaction time, and work-up procedure. Therefore, I would not treat a certificate of analysis alone as proof that a material will perform identically in every process; application-specific verification remains necessary.

Specifications Buyers Should Review

Identity and Basic Description

The first review should confirm CAS 5720-05-8, chemical name, molecular formula, molecular weight, and the supplier’s internal product code. The product description should be consistent across the quotation, label, specification sheet, safety data sheet, and COA. I also recommend checking whether the document refers specifically to 4-Tolylboronic acid rather than a positional isomer or a different substituted arylboronic acid.

Appearance may be included in the specification, but it should be interpreted carefully. Color, physical form, and particle characteristics can be affected by production, drying, storage, and packaging conditions. If appearance is critical to your process, request the supplier’s defined acceptance language instead of relying on a general description such as “white to off-white powder.”

Assay, Impurities, and Analytical Method

Assay is important, but the reported value should always be read together with the test method and calculation basis. Common supporting tests may include HPLC, NMR, water determination, residual solvent analysis, and elemental or inorganic impurity testing, depending on the grade and intended use. A buyer should ask whether the reported assay is area percentage, mass percentage, or another stated basis, because these values are not automatically interchangeable.

For process development, the impurity profile may matter more than a single headline assay number. Potential concerns can include unreacted starting materials, regioisomeric impurities, oxidation or decomposition products, inorganic residues, and residual solvents. I recommend identifying which impurities are process-sensitive and asking the supplier to confirm whether those items are routinely monitored or only tested upon request.

COA Review Checklist

A useful COA should identify the product, lot number, manufacturing or testing date where applicable, test results, specification limits, analytical methods, and approval or authorization details. The lot number should match the container label and commercial paperwork. If the document only states “pass” without numerical results or method references, I would request a fuller version before completing qualification.

Matching the Material to the Application

For medicinal chemistry and small-molecule discovery, buyers often need dependable identity confirmation, suitable analytical purity, and practical package sizes. In this setting, a clear COA and a representative sample can be more valuable than negotiating a large volume price too early. The researcher should also confirm solubility and reaction compatibility through a small-scale experiment rather than assuming that all lots will behave the same in every solvent system.

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For process development, the focus should move toward lot-to-lot consistency, impurity control, drying history, packaging integrity, and supply planning. If a reaction is sensitive to water or inorganic residues, those parameters should be written into the purchasing specification before scale-up. For example, a 0.10 mol reaction requires approximately 13.60 g of 4-Tolylboronic acid on a theoretical one-equivalent basis, calculated from the approximate molecular weight of 135.96 g/mol; the actual charge must then account for stoichiometry, assay, and process yield.

For commercial or repeated purchasing, the buyer should evaluate forecast visibility, batch reservation options, shipping conditions, export documentation, and notification procedures for specification or manufacturing changes. A supplier that can discuss these points clearly may reduce operational risk even when its quoted unit price is not the lowest. The final selection should reflect total sourcing cost, including testing, qualification, inventory, freight, and potential production delays.

Supplier Evaluation Framework

Questions to Ask Before Ordering

1. Can you confirm the product identity as 4-Tolylboronic acid, CAS 5720-05-8?
2. What assay and impurity specifications apply to the quoted grade?
3. Which analytical methods are used, and can numerical COA results be provided?
4. Is the quoted material from an existing lot or a future production batch?
5. What package sizes, minimum order quantities, and production lead times are available?
6. Can you provide a sample, SDS, specification sheet, and representative COA for review?
7. How are lot traceability, packaging, storage, and change notifications managed?

I recommend requesting documentation before placing a bulk order, especially when the material will enter a regulated or tightly controlled development workflow. The buyer should compare documents from at least two suppliers using the same checklist, rather than comparing only catalog prices. If the intended use is critical, qualification can include testing multiple lots and defining acceptance criteria before routine purchasing.

Pricing, MOQ, and Lead-Time Considerations

Pricing for 4-Tolylboronic acid can vary with purity, analytical package, order quantity, packaging, production route, destination, and current raw-material availability. A quotation for a 1 kg development order should not be compared directly with a quotation for a larger contract volume unless freight, testing, packaging, and delivery terms are also aligned. I advise buyers to request tiered pricing and to state whether the requirement is a one-time order or a recurring forecast.

Minimum order quantity and lead time are not universal product characteristics, so they should be confirmed in writing for each quotation. Stock availability may support faster shipment, while a scheduled manufacturing batch may offer different documentation or pricing. Before approving a supplier, confirm the validity period of the quote, estimated dispatch timing, packaging configuration, and the process for handling delays or partial shipments.

Common Purchasing Mistakes

One common mistake is approving material based only on the product name and CAS number. Identity is essential, but it does not define assay, impurity limits, water content, packaging, or analytical documentation. Another mistake is requesting a COA only after the shipment arrives, when the material may already be difficult to reject or replace.

Buyers should also avoid treating a generic “high purity” statement as a complete specification. Ask for the actual limits, test methods, and whether results are reported for every lot or for a representative batch. Finally, do not assume that a successful reaction using one sample guarantees equivalent performance after scale-up; process-sensitive impurities and handling history should be evaluated as part of technical transfer.

How Maison Chemical Can Support Your Sourcing Review

At Maison Chemical, we support B2B buyers evaluating 4-Tolylboronic acid CAS 5720-05-8 for research, development, and bulk supply programs. Our role is to help align the requested grade with the customer’s intended use, quantity, documentation needs, and delivery plan. Product availability, specifications, packaging, MOQ, and lead time should be confirmed for each inquiry rather than assumed in advance.

When you contact us, please include your required quantity, destination country, target specification, preferred packaging, and whether you need a sample or representative COA. If your quality team has a specific testing method or document format, sharing it at the quotation stage can make technical review more efficient. We can then assess the inquiry and provide a commercially relevant response based on the requested supply conditions.

Key Takeaways

• 4-Tolylboronic acid CAS 5720-05-8 is an arylboronic acid building block used in organic synthesis and cross-coupling applications.
• Its commonly referenced molecular weight is approximately 135.96 g/mol, but buyers should verify identity across all supplier documents.
• A complete COA review should cover identity, assay, impurities, analytical methods, lot traceability, and document consistency.
• Application requirements determine whether the priority should be research-scale flexibility, impurity control, or long-term supply continuity.
• MOQ, price, packaging, and lead time must be confirmed in a written quotation for the specific order quantity and destination.

Conclusion and Next Steps

The best way to buy 4-Tolylboronic acid CAS 5720-05-8 is to evaluate more than the catalog name and price. First, confirm identity and grade; next, review the COA and analytical basis; then compare supplier capability, packaging, MOQ, lead time, and documentation support against your actual application. This approach gives procurement, R&D, and quality teams a clearer basis for qualification and reduces avoidable sourcing risk.

For a quotation from Maison Chemical, send your target quantity, specification requirements, destination, and documentation expectations. We can review whether the requested material is suitable for your sourcing program and clarify the available supply route, commercial terms, and technical documents. That information will allow your team to make a more informed decision for sample purchase, project development, or bulk procurement.

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