4-Pentylbenzeneboronic acid, CAS 121219-12-3, is an alkyl-substituted aryl boronic acid used primarily as a building block for carbon–carbon bond formation, especially Suzuki–Miyaura coupling. Its boronic acid group provides a practical reaction handle, while the para-pentyl substituent introduces a hydrophobic, flexible alkyl segment into the target molecule. I recommend evaluating this material by identity, assay, water content, appearance, packaging, batch consistency, and supplier support rather than by CAS number alone. Maison Chemical supplies 4-Pentylbenzeneboronic acid for research, process development, and commercial sourcing discussions, subject to project-specific specifications and availability.
4-Pentylbenzeneboronic acid is an aryl boronic acid in which a pentyl group is positioned para to the boronic acid functionality on a benzene ring. The compound is also described as 4-amylphenylboronic acid in some technical or commercial contexts, although buyers should use the CAS number and supplier documentation to confirm identity. Its boronic acid group can participate in transmetalation during palladium-catalyzed Suzuki–Miyaura coupling.
The compound has the molecular formula C11H17BO2 and a calculated molecular weight of approximately 192.07 g/mol. These values are useful for reaction planning, stoichiometric calculations, and procurement review, but they do not replace a batch-specific certificate of analysis. The physical appearance, assay, water content, and stability profile should be confirmed from the actual product specification.
The most important use of 4-Pentylbenzeneboronic acid is as an aryl donor in Suzuki coupling. In a typical transformation, the aryl boronic acid reacts with an aryl, heteroaryl, or vinyl halide in the presence of a suitable palladium catalyst and base to form a new carbon–carbon bond. The boronic acid portion is converted into a leaving group during the catalytic cycle, while the pentyl-substituted aryl fragment becomes part of the final product.
Reaction conditions depend on the coupling partner, catalyst, solvent, base, concentration, and temperature. Common development screens may compare bases such as carbonate, phosphate, or hydroxide systems and solvents such as aqueous alcohol, ethers, or polar aprotic media. I advise treating these as starting points only, because catalyst loading and reaction performance must be established experimentally for each substrate pair.
The para-pentyl group provides a relatively hydrophobic and flexible substituent that can influence solubility, partitioning, molecular packing, and overall lipophilic character. In medicinal chemistry, this type of substituent may be introduced during analogue synthesis to explore structure–activity relationships. In materials or organic electronics research, the alkyl chain may also affect processability and interactions between molecules, although the final effect depends on the complete molecular structure.
Research teams may use this intermediate when they need to prepare substituted biphenyls, biaryl heterocycles, or other conjugated structures containing a pentylphenyl unit. It can be useful in route scouting because Suzuki coupling tolerates a broad range of functional groups, although compatibility must be assessed for each substrate. The material may also support parallel synthesis, medicinal-chemistry library preparation, and early-stage process development.
For process chemistry, the key question is not only whether the reaction works at small scale, but whether impurity control, filtration, solvent selection, and residual palladium management are practical at larger scale. A material that performs well in a 10 mg experiment may require different handling at a 10 g or kilogram scale. I therefore recommend reviewing both the reaction route and the raw-material supply plan before committing to a production schedule.
| Evaluation item | Why it matters | What buyers should request |
|---|---|---|
| Identity | Confirms that the supplied material matches the intended intermediate. | CAS number, name, molecular formula, and analytical identification. |
| Assay or purity | Influences stoichiometry, impurity load, and reaction reproducibility. | Batch-specific assay method and acceptance criterion. |
| Water content | Boronic acids can be affected by moisture during storage and handling. | Water specification or Karl Fischer result when relevant. |
| Analytical package | Supports internal release and technical qualification. | COA, HPLC or GC data where applicable, NMR data, and SDS. |
| Packaging | Reduces exposure to moisture, contamination, and unsuitable storage conditions. | Container type, net weight, labeling, and recommended storage. |
For purchasing purposes, the molecular weight of approximately 192.07 g/mol provides a clear calculation basis. For example, 1.00 mol corresponds to approximately 192.07 g before considering assay correction, solvent content, or handling losses. I recommend correcting the weighed amount using the supplier’s reported assay when the reaction requires accurate molar equivalence.
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First, identify the coupling partner, target scale, functional-group environment, and acceptable impurity profile. A simple aryl halide may require less development than a sterically hindered heteroaryl substrate or a molecule containing base-sensitive functionality. This information helps the supplier propose an appropriate grade, package size, and documentation set.
For early discovery work, a standard research-grade specification may be sufficient if the laboratory can independently verify the material. For process development or regulated projects, buyers may require tighter impurity limits, trace-metal information, controlled documentation, and change-notification support. I recommend agreeing on the required tests before quotation rather than requesting them after delivery.
Price should be evaluated together with MOQ, available stock, production lead time, packaging, shipping route, and document completeness. A lower unit price may not be advantageous if the order requires a long manufacturing cycle or creates a qualification risk. Ask for pricing at the actual project quantities, such as 100 g, 500 g, or 1 kg, because volume-based pricing can differ substantially.
One common mistake is assuming that a CAS number guarantees identical commercial quality across suppliers. It confirms a chemical identity reference, but it does not by itself define assay, residual solvents, water content, particle characteristics, or packaging performance. Another mistake is requesting a quotation without stating the required quantity, delivery destination, and documentation expectations.
Buyers should also avoid transferring the material into unsuitable containers or leaving it exposed to humid laboratory air for extended periods. The exact storage recommendation should come from the supplier’s SDS and product specification. When a coupling reaction shows inconsistent conversion, investigate substrate quality, catalyst and base selection, moisture exposure, and analytical method suitability before concluding that the boronic acid is the sole cause.
At Maison Chemical, I support customers by clarifying product identity, discussing intended application, preparing commercial quotations, and coordinating documentation for technical review. Depending on the project, the document package may include a certificate of analysis, safety data sheet, product specification, and available analytical information. The exact package should be confirmed before order placement because requirements vary between research, process, and manufacturing organizations.
We also recognize that supply decisions involve more than a single product price. Customers may need staged quantities for route development, repeat-batch planning, export packaging, or production continuity. By sharing the target quantity, desired delivery date, destination country, and quality requirements, buyers can receive a more useful supply assessment from the beginning.
4-Pentylbenzeneboronic acid CAS 121219-12-3 is a useful aryl boronic acid intermediate when a synthesis requires a pentyl-substituted phenyl fragment, particularly through Suzuki–Miyaura carbon–carbon coupling. Its value comes from combining a practical boronic acid reaction handle with a defined hydrophobic alkyl substituent. However, suitability must be demonstrated against the specific coupling partner, reaction conditions, scale, and impurity-control requirements.
My recommended next step is to send Maison Chemical your required quantity, target application, destination, preferred delivery schedule, and documentation requirements. We can then help confirm the appropriate specification, quotation basis, packaging, and supply route. This structured approach gives R&D, procurement, and process-development teams a clearer basis for technical qualification and purchasing decisions.
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