4-Butylphenylboronic Acid CAS 145240-28-4: Properties, Applications, and Buying Guide

4-Butylphenylboronic acid, CAS 145240-28-4, is an aryl boronic acid used primarily as a coupling partner in palladium-catalyzed Suzuki–Miyaura reactions. Its para-butyl substituent combines the reactive boronic acid group with a hydrophobic alkyl chain, making the compound relevant to pharmaceutical, agrochemical, specialty-material, and medicinal-chemistry research. The molecular formula is commonly represented as C₁₀H₁₅BO₂, with a calculated molecular weight of approximately 178.04 g/mol. I recommend confirming identity, assay, water content, and handling requirements against the current supplier certificate of analysis before purchase.

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In this guide, I explain the compound’s identity, chemical function, application fit, specification priorities, sourcing considerations, and supplier-evaluation process. I also distinguish product facts from project-dependent recommendations, because reaction performance depends on the coupling partner, catalyst system, solvent, scale, and work-up conditions. For reference, PubChem provides a useful authoritative starting point for checking chemical identifiers and structure information for boronic acids and related compounds. Source: U.S. National Library of Medicine, PubChem.

Quick Summary for Buyers

• Product: 4-Butylphenylboronic acid
• CAS number: 145240-28-4
• Formula: C₁₀H₁₅BO₂
• Approximate molecular weight: 178.04 g/mol
• Primary chemical role: Aryl-boron coupling reagent
• Main application: Suzuki–Miyaura and related cross-coupling research
• Key purchasing checks: Identity, assay, water content, residual solvents, packaging, and lot-specific documentation

Who This Buying Guide Is For

This guide is intended for R&D chemists, process-development teams, procurement specialists, contract research organizations, and chemical distributors evaluating 4-butylphenylboronic acid. It is particularly relevant when a project requires an aryl boronic acid with a para-n-butyl substituent rather than an unsubstituted phenylboronic acid or a different alkyl-substituted analogue. The information can also support initial supplier qualification before a formal technical review.

I do not treat this compound as a universal reagent for every carbon–carbon bond-forming reaction. The correct choice depends on the target structure, electrophilic partner, catalyst compatibility, base, solvent, temperature, and required impurity profile. Buyers should therefore compare the exact structural isomer and CAS number rather than relying only on a similar product name.

Basic Chemical Context

4-Butylphenylboronic acid contains a boronic acid functional group attached to an aromatic ring and a butyl substituent positioned at the para, or 4-, position relative to the boronic acid group. The boronic acid group is the chemically reactive portion used in many cross-coupling designs, while the butyl group modifies the steric, hydrophobic, and molecular-property profile of the aryl fragment. This combination can be useful when a final molecule requires a nonpolar or lipophilic substituent.

In Suzuki–Miyaura chemistry, an aryl boronic acid commonly reacts with an aryl or vinyl halide, pseudohalide, or related electrophile in the presence of a suitable catalyst and base. The boronic acid is not normally the final functional group in the target molecule; instead, it serves as a transferable aryl component. The actual reaction conditions must be established experimentally or selected from validated literature procedures for the specific substrate pair.

The compound’s approximate molecular weight of 178.04 g/mol is useful for calculating reagent quantities and preparing solutions. For example, a theoretical 1.00 mmol amount corresponds to approximately 178 mg before accounting for assay, water, or other lot-specific corrections. I recommend using the assay value shown on the certificate of analysis when converting from molar demand to weighed mass.

Properties and Key Specifications

Identity and Composition

The first specification check should confirm the product name, CAS 145240-28-4, molecular formula, molecular weight, and structural isomer. A supplier should be able to provide a lot-specific certificate of analysis or equivalent technical document. Depending on the intended use, buyers may also request an analytical summary such as HPLC, GC, NMR, or other identity data, provided that the method is appropriate for the compound.

Physical and Handling Information

The appearance, melting behavior, solubility, and stability profile should be taken from the supplier’s current specification and safety documentation rather than assumed from the name alone. Boronic acids can be sensitive to moisture, storage conditions, and repeated container opening, and their behavior may vary with purity, particle size, and packaging. I recommend keeping the material in its original, tightly closed container and following the supplier’s SDS for temperature, ventilation, personal protective equipment, and waste handling.

Solubility should be evaluated in the actual project solvent. An apparent concentration such as 0.10 mol/L may be practical in one solvent system but unsuitable in another, so it should not be treated as a guaranteed product property. Before scale-up, I suggest a small compatibility check using the intended solvent, base, catalyst, and reaction concentration.

For safety decisions, buyers should consult the current SDS and applicable regulatory requirements. PubChem’s chemical safety and structure resources can assist with preliminary information, but they do not replace the supplier’s lot-specific documentation or the user’s institutional risk assessment. Source: PubChem compound information.

Application Matching

Suzuki–Miyaura Coupling

The most direct application is the construction of biaryl or aryl–alkenyl structures through Suzuki–Miyaura coupling. In a typical design, 4-butylphenylboronic acid supplies the 4-butylphenyl fragment to an electrophilic partner such as an aryl bromide, aryl iodide, or selected aryl chloride. Catalyst loading, base selection, solvent, temperature, and reaction time should be optimized for the particular substrate rather than copied without evaluation.

The butyl substituent may be selected when the target molecule needs increased hydrocarbon content or a hydrophobic side chain. This can be relevant to medicinal-chemistry analogues, organic-material intermediates, and exploratory structure–property studies. However, the presence of a butyl group does not by itself demonstrate a specific biological, electronic, or materials-performance outcome.

Medicinal and Agrochemical Intermediate Research

In medicinal and agrochemical discovery, this reagent can support the preparation of compound libraries containing a para-butyl-substituted biaryl motif. Its value is greatest when the project requires rapid variation of the electrophilic coupling partner while retaining the same hydrophobic aryl fragment. Final suitability still depends on downstream purification, residual palladium requirements, impurity control, and the regulatory status of the resulting product.

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Specialty Materials and Building-Block Development

Research teams developing functional aromatic intermediates may also consider this compound as a building block. The actual value depends on how the para-butyl group affects solubility, molecular packing, processability, or compatibility with the rest of the structure. These effects should be verified through project-specific measurements rather than inferred only from the presence of the alkyl chain.

How to Select the Right Grade and Supply Format

Step 1: Confirm Structural Identity

Start by matching the requested name, CAS number, molecular formula, and structure. The “4-” designation is important because positional isomers can have different reactivity, physical behavior, and commercial availability. I recommend requesting a structure image or technical data sheet when the material will be used in a regulated or multi-site development program.

Step 2: Define the Required Purity

Do not select purity solely by habit. A discovery-scale reaction may require a different specification from a process route, an analytical reference material, or a downstream pharmaceutical intermediate. Discuss the acceptable assay range, known impurities, water content, residual solvents, and analytical method with the technical supplier before placing a larger order.

Step 3: Check Packaging and Storage

Packaging should reflect the order size, expected opening frequency, shipping conditions, and moisture sensitivity of the project. For example, a 1 g development pack and a 100 g process-development pack may require different container and labeling considerations. The supplier should communicate recommended storage conditions, retest or review information where applicable, and precautions for repeated use.

Step 4: Verify Documentation

At minimum, I suggest requesting a current SDS, certificate of analysis, product specification, batch or lot identification, and country-of-origin information where relevant to your procurement process. If the material is intended for a regulated workflow, request the additional quality documents required by your internal qualification system. Documentation should be reviewed before shipment, not only after the material arrives.

Buyer Selection Framework

Pricing, MOQ, and Lead-Time Considerations

The price of 4-butylphenylboronic acid can vary with assay, order quantity, packaging, production route, analytical requirements, and shipping destination. I do not recommend using a generic online price as a reliable budget figure because small laboratory packs and bulk quotations are not directly comparable. A formal quotation should state the quantity, specification, packaging, Incoterms where applicable, validity period, and documentation included.

Minimum order quantity and lead time should also be confirmed for the exact grade. Stock availability may support a short dispatch window, while a made-to-order or customized specification may require additional production and testing time. For planning purposes, buyers should request both the current availability and an expected repeat-supply timeline instead of relying on a single shipment estimate.

Maison Chemical can review inquiries for 4-butylphenylboronic acid based on required quantity, purity target, packaging, destination, and documentation needs. We can also help clarify whether the request is for laboratory research, process development, distribution, or a custom supply program. Final commercial terms should be confirmed in a written quotation.

Common Purchasing Mistakes

• Confusing positional isomers: “4-butyl” should be verified against the structure and CAS number.
• Ignoring assay correction: weighed quantity should be adjusted when the lot assay is below the nominal value.
• Assuming solubility: solvent compatibility should be tested at the intended concentration and temperature.
• Buying without documentation: an SDS and lot-specific COA are important for safe handling and technical review.
• Comparing only unit price: packaging, testing, freight, lead time, and supply continuity can materially affect total procurement cost.
• Scaling a literature procedure blindly: catalyst, base, solvent, concentration, and substrate effects may change at larger scale.

How Maison Chemical Supports B2B Buyers

At Maison Chemical, I approach this product as a technical sourcing requirement rather than a simple catalog transaction. We can discuss the requested CAS number, target quantity, purity expectation, packaging format, destination, and documentation package before quotation. This helps reduce avoidable mismatches between the material ordered and the material required by the laboratory or manufacturing team.

For repeat users, I recommend sharing an estimated demand schedule and acceptance criteria early in the sourcing process. We can then review whether the requested specification is suitable for the intended synthesis and whether a standard or customized supply format is more practical. Any proposed specification, availability, and lead time remain subject to confirmation for the specific order.

Recommended Next Steps

1. Confirm that the required structure is 4-butylphenylboronic acid, CAS 145240-28-4.
2. Define the target quantity, assay requirement, packaging, and intended application.
3. Request the current specification, SDS, COA example or lot-specific COA, and availability status.
4. Evaluate a small quantity in the intended reaction system before process-scale purchasing.
5. Request a written quotation from Maison Chemical with commercial and documentation details clearly stated.

Conclusion

4-Butylphenylboronic acid CAS 145240-28-4 is an aryl boronic acid building block with an approximate molecular weight of 178.04 g/mol and a primary role in cross-coupling research. It is most suitable when a project needs to introduce a 4-butylphenyl fragment into a larger molecule, particularly through Suzuki–Miyaura chemistry. The best buying decision depends on confirmed identity, lot-specific quality data, handling requirements, documentation, and dependable supply—not on product name or price alone.

For your next step, define the required quantity and specification, then ask Maison Chemical to review the application and provide a quotation. We can support a technical discussion covering purity, packaging, documentation, MOQ, lead time, and repeat-order planning for 4-butylphenylboronic acid.

Request a 4-butylphenylboronic acid quotation from Maison Chemical by sharing your target quantity, purity requirement, packaging preference, destination, and delivery schedule.