What Is 4-Pentylbenzeneboronic Acid (CAS 121219-12-3)?

18, Aug. 2026

 

What Is 4-Pentylbenzeneboronic Acid (CAS 121219-12-3)?

4-Pentylbenzeneboronic acid, identified by CAS 121219-12-3, is an aromatic boronic acid used as a research and synthetic building block. Its structure combines a phenyl ring, a pentyl substituent in the para position, and one boronic acid functional group. Based on its molecular composition, its molecular formula is C11H17BO2, with a calculated molar mass of approximately 192.07 g/mol. In B2B procurement, buyers generally evaluate this compound by identity, purity documentation, analytical data, packaging, lead time, and suitability for the intended reaction route.

You can find more information on our web, so please take a look.

Identity and Chemical Profile

The name “4-pentylbenzeneboronic acid” describes the arrangement of the molecule. The pentyl group is attached to the fourth, or para, position of the benzene ring relative to the boronic acid group. The molecule therefore contains one five-carbon alkyl chain and one boronic acid group attached to an aromatic system.

Property Information
Product name 4-Pentylbenzeneboronic acid
CAS number 121219-12-3
Molecular formula C11H17BO2
Calculated molar mass Approximately 192.07 g/mol
Key functional group One aryl boronic acid group
Substituent One para-position pentyl chain containing 5 carbon atoms

The boronic acid group is the principal reactive feature of this compound. Like other aryl boronic acids, it may participate in carbon–carbon bond-forming chemistry under suitable reaction conditions, including Suzuki–Miyaura-type coupling with an appropriate halide or related electrophile. However, actual reaction performance depends on the reaction partners, catalyst system, solvent, base, temperature, water content, and work-up procedure.

Core Functions in Chemical Synthesis

In synthetic chemistry, 4-pentylbenzeneboronic acid can serve as an aryl fragment donor. The pentyl substituent adds a nonpolar, flexible alkyl segment to the resulting molecule, while the boronic acid group provides a site for further transformation. This combination can be useful when a target structure requires both an aromatic ring and a hydrophobic side chain.

Role in Cross-Coupling Research

A common reason to purchase this material is to investigate arylation or biaryl formation. In a typical coupling concept, the aryl boronic acid reacts with a compatible halogenated or pseudohalogenated partner in the presence of a suitable catalytic system. I recommend treating this as a route-development starting point rather than assuming that every substrate pair will provide the same yield or selectivity.

Use as a Building Block

The compound may also be considered during medicinal chemistry, materials research, and intermediate development where a para-pentylphenyl unit is required. Its value is structural: it allows a specific aromatic substitution pattern to be introduced through a commercially identifiable intermediate. Whether it is the best choice depends on the target molecule, downstream functional-group tolerance, and the availability of alternative precursors.

Potential Application Scenarios

Research teams may evaluate 4-pentylbenzeneboronic acid during small-molecule synthesis and library development. The para-pentyl group can influence molecular hydrophobicity, steric environment, and physical behavior, so the compound may be selected when these structural characteristics are part of the design hypothesis. These are potential use cases, not a guarantee of performance in a particular biological, electronic, or materials application.

Another scenario is route scouting for custom intermediates. A process chemist may compare this boronic acid with a corresponding aryl halide, protected boronate ester, or another substituted phenyl building block. The preferred route is normally determined by reaction robustness, impurity control, raw-material availability, process safety, and downstream purification requirements.

For materials-oriented research, the compound may be explored as one component in the preparation of functionalized aromatic molecules. The long alkyl chain can modify the balance between aromatic and aliphatic character in a final structure. I recommend confirming the final application through laboratory testing because a structural feature that is useful in one formulation may be unsuitable in another.

Material and Product Form Considerations

When sourcing this chemical, buyers should first confirm whether they need the free boronic acid specifically. Boronic acid derivatives can also be supplied in other chemical forms, such as protected boronate esters, but those materials are not interchangeable without considering reaction conditions and deprotection requirements. A clear purchase specification should therefore state the exact name, CAS number, molecular formula, required purity, and preferred analytical documentation.

For more information, please visit Maison Chemical.

Product presentation may vary by supplier and project stage. Research quantities, development quantities, and larger production-support quantities can involve different packaging, documentation, and lead-time expectations. I do not recommend assuming that a catalog listing, package size, or delivery schedule applies to every batch; these points should be confirmed in a written quotation.

Key Specifications Buyers Should Review

The first specification is identity confirmation. The CAS number 121219-12-3 should correspond to the requested compound, while the formula and calculated molar mass provide additional cross-checks for purchasing and laboratory records. Buyers should also confirm whether the supplier provides a batch-specific certificate of analysis rather than only a general product description.

Purity and Analytical Data

Purity should be reviewed in the context of the intended reaction and quality system. Useful documentation may include chromatographic purity, water content where relevant, residual solvent information, and analytical spectra such as NMR or mass spectrometry. The exact acceptance criteria should be agreed before order placement because “high purity” is not a sufficiently precise requirement for every process.

Physical Handling Information

Appearance, solubility, storage recommendations, and stability information can affect laboratory planning. Boronic acids may show different behavior depending on solvent, moisture exposure, concentration, and storage conditions, so the supplier’s handling guidance should be considered alongside internal safety procedures. I recommend requesting the safety data sheet and technical handling information before the material enters a production or research workflow.

Buyer Selection Factors

For a first purchase, I suggest evaluating five areas: verified identity, appropriate purity, batch documentation, packaging suitability, and supply responsiveness. A low unit price is not necessarily the lowest total cost if the material requires additional testing, arrives in unsuitable packaging, or causes delays in route development. Buyers should compare quotations using the same quantity, specification, documentation level, and delivery destination.

  • Identity: Confirm the name, CAS number, formula, and molecular mass.
  • Quality: Define the required assay or chromatographic purity before quotation.
  • Documentation: Request a batch-specific certificate of analysis and safety data sheet.
  • Packaging: Match the container and quantity to the expected handling period.
  • Supply: Confirm stock status, production lead time, minimum order quantity, and shipping conditions.

For process development, I also recommend asking whether the same specification can be maintained across repeat batches. Consistency is especially important when a material is used in comparative experiments, impurity studies, or scale-up planning. If the compound is being considered for regulated or quality-controlled work, documentation expectations should be discussed before technical approval.

How Maison Chemical Can Support Sourcing

At Maison Chemical, I approach 4-pentylbenzeneboronic acid as a specification-driven B2B chemical requirement rather than a simple product-name inquiry. We can help organize the request around CAS 121219-12-3, required quantity, target purity, packaging, destination, and documentation needs. This approach helps reduce ambiguity between the material requested by a laboratory and the material quoted by a supplier.

Before confirming supply, I recommend that buyers provide their intended use category and any critical quality attributes. For example, a screening project may prioritize small-quantity availability and analytical confirmation, while a scale-up project may place greater emphasis on batch continuity, packaging, and lead-time planning. Final availability, commercial terms, and specifications should always be confirmed through a current quotation.

Summary Insight

4-Pentylbenzeneboronic acid, CAS 121219-12-3, is an aromatic boronic acid building block with a para-position pentyl substituent. Its key identity data include the formula C11H17BO2, a calculated molar mass of approximately 192.07 g/mol, one boronic acid functional group, and a five-carbon alkyl chain. Its potential value comes from combining a cross-coupling-capable aryl boronic acid group with a defined hydrophobic structural segment.

The correct sourcing decision depends on more than the chemical name. I recommend confirming identity, purity, analytical documentation, packaging, storage guidance, minimum order quantity, lead time, and repeat-batch expectations before purchase. If you are evaluating 4-pentylbenzeneboronic acid for synthesis, process development, or an intermediate program, contact Maison Chemical with your required quantity and specification so we can prepare a suitable B2B quotation and sourcing plan.

For more 4-Pentylbenzeneboronic acid CAS 121219-12-3information, please contact us. We will provide professional answers.