3-Carboxyphenylboronic acid, CAS 25487-66-5, is an aromatic boronic acid building block that combines a boronic acid group with a meta-carboxylic acid group on the same benzene ring. I consider it a useful intermediate for Suzuki-Miyaura coupling, medicinal chemistry, and the preparation of functionalized aromatic compounds because it can introduce both an aryl fragment and a carboxylic acid handle. Its molecular formula is commonly represented as C7H7BO4, with a molecular weight of approximately 165.94 g/mol. In practice, successful use depends on substrate compatibility, reaction conditions, product quality, and the supplier’s documentation.
This guide is intended for process chemists, medicinal chemistry teams, procurement specialists, and R&D organizations evaluating 3-Carboxyphenylboronic acid for laboratory or scale-up work. It is also relevant to buyers comparing pharmaceutical intermediate manufacturers and specialty chemical suppliers. I focus on practical selection, reaction planning, quality review, and sourcing considerations rather than presenting one universal synthesis protocol.
The compound may be suitable when a project requires a substituted biaryl or aryl-heteroaryl structure that retains a carboxylic acid group for subsequent derivatization. However, I recommend confirming the intended transformation at small scale before committing to larger quantities. Boronic acids can show different behavior depending on solvent, base, temperature, substrate electronics, and storage history.
3-Carboxyphenylboronic acid contains two strategically useful functional groups. The aryl boronic acid moiety participates in palladium-catalyzed cross-coupling with suitable aryl, heteroaryl, or vinyl electrophiles, while the carboxylic acid can remain available for amide formation, esterification, salt formation, or other downstream chemistry. Because the two groups are positioned in the meta relationship, the compound can provide a defined substitution pattern that is not interchangeable with the ortho- or para-isomers.
In a Suzuki-Miyaura reaction, the boronic acid group generally acts as the organoboron coupling partner. The reaction typically requires a compatible electrophile, a palladium catalyst or palladium-based catalytic system, a base, and a solvent system selected for the substrate pair. I treat the carboxylic acid as a potentially influential group because it can affect solubility, acid-base balance, purification, and the apparent performance of the reaction mixture.
| Item | Information |
|---|---|
| Product name | 3-Carboxyphenylboronic acid |
| CAS number | 25487-66-5 |
| Approximate molecular formula | C7H7BO4 |
| Approximate molecular weight | 165.94 g/mol |
| Functional groups | Aryl boronic acid and carboxylic acid |
Commercial material may be supplied as a solid, but appearance, assay, water content, residual solvents, and impurity profile should be confirmed from the current batch documentation. I do not recommend treating a catalog description as a substitute for a certificate of analysis. For a reaction-critical purchase, buyers should request the actual specification, analytical method, retest or recommended storage information, and packaging details before placing a production-oriented order.
At minimum, I suggest reviewing assay, identity confirmation, water content, residual solvents, and related organic impurities. Depending on the application, buyers may also request elemental or inorganic impurity information, heavy-metal data, and chromatographic records. The appropriate acceptance limits should be defined by the customer’s process rather than assumed to be identical for every research or manufacturing use.
For Suzuki-Miyaura coupling, 3-Carboxyphenylboronic acid is most relevant when the target molecule needs a meta-carboxy-substituted aryl unit. The electrophile may be an aryl halide or another validated coupling partner, although reactivity can vary substantially across substrates. A practical development approach is to screen the base, solvent, catalyst system, temperature, and reaction time using a small quantity of material before scaling.
Catalyst loading is substrate-dependent, but an initial development screen may evaluate a range such as 0.5–2 mol% palladium catalyst rather than assuming one fixed value. The boronic acid may be used near stoichiometric quantity or with a modest excess, depending on conversion and selectivity. These figures are starting points for process development, not guaranteed specifications or universal operating conditions.
The retained carboxylic acid can be useful for preparing amides, esters, or other analogues after the carbon-carbon bond-forming step. This makes the compound relevant to parallel synthesis and structure-activity relationship programs where a common aromatic intermediate is diversified through multiple downstream reactions. I recommend evaluating protection or deprotection needs if the carboxylic acid interferes with solubility, catalyst coordination, or purification.
The compound may also be considered for research involving functionalized aromatic scaffolds, linker design, and specialty intermediates. Suitability should be judged by the required substitution pattern and the tolerance of the planned chemistry. If the project does not require both a boronic acid and a carboxylic acid, a simpler boronic acid or a protected analogue may offer easier handling or purification.
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First, I confirm that the required isomer is the 3-substituted compound and that CAS 25487-66-5 matches the internal material record. I then review the planned electrophile, catalyst system, and downstream transformations. This step helps prevent the common purchasing error of selecting a positional isomer with similar naming but different synthetic value.
Research screening may tolerate a different specification from a regulated intermediate or a process-development batch. For early discovery, assay and identity may be the principal criteria, while later-stage work may require tighter control of water, residual solvents, metals, and specific impurities. I recommend agreeing on these requirements before requesting quotations so that supplier offers can be compared fairly.
Ask how the material should be stored, how the package is sealed, and whether the supplier provides a recommended retest period. Boronic acids may be sensitive to moisture or prolonged unfavorable storage conditions, so packaging and logistics can influence practical performance. A buyer should also confirm whether the product is shipped under conditions appropriate for the planned transit route.
Minimum order quantity and lead time vary according to stock status, batch size, specification, and whether custom manufacturing is required. I advise requesting separate quotations for laboratory quantities, development quantities, and repeat commercial supply. A low initial price may not represent the best value if documentation, consistency, or replenishment capacity is inadequate.
One common mistake is assuming that all boronic acids behave identically in coupling reactions. The carboxylic acid group can influence aqueous solubility and the reaction pH, while the electronic properties of the electrophile may affect conversion. I therefore recommend controlled experiments that compare isolated yield, impurity formation, and work-up performance rather than judging a condition only by apparent reaction completion.
Another mistake is overlooking the difference between reaction conversion and isolated product quality. Residual boron-containing species, palladium residues, unreacted starting material, and difficult-to-remove by-products may become more important during scale-up. A useful development record should include reaction concentration, equivalents, catalyst loading, temperature in degrees Celsius, reaction time in hours, work-up method, and purification observations.
For optimization, I would normally begin with a small matrix of bases and solvent systems compatible with both the electrophile and the carboxylic acid. Aqueous-organic mixtures can be useful in some cases, but the best system depends on substrate solubility and catalyst stability. If the free acid causes handling difficulties, the team may compare a protected carboxylate strategy, provided that the protection and deprotection steps are acceptable for the overall route.
A suitable supplier should be able to provide clear product identification, a current certificate of analysis, batch-specific analytical information, packaging options, and realistic lead-time guidance. I also recommend asking whether the material is manufactured in-house, sourced through a qualified network, or supplied according to a customer-specific specification. This distinction can affect continuity of supply and the ability to investigate batch-to-batch differences.
Maison Chemical supports B2B buyers evaluating 3-Carboxyphenylboronic acid CAS 25487-66-5 for research, development, and intermediate-sourcing programs. We can discuss required quantity, target specification, documentation needs, packaging, and shipment planning before quotation. Where the application is technically sensitive, I recommend sharing the intended use and acceptance criteria so that the proposed supply route can be reviewed against the project’s actual requirements.
3-Carboxyphenylboronic acid CAS 25487-66-5 is a dual-functional aromatic building block with an aryl boronic acid group for Suzuki-Miyaura coupling and a carboxylic acid group for subsequent derivatization. Its approximate molecular weight is 165.94 g/mol, but practical suitability depends on verified identity, assay, water content, impurities, and the requirements of the target route. Reaction conditions should be developed for the specific substrate combination rather than copied without evaluation.
For buyers, the most important next steps are to define the required specification, request batch documentation, confirm packaging and storage guidance, and compare supplier capacity for repeat orders. Maison Chemical can support quotation and technical discussions for 3-Carboxyphenylboronic acid supply. Contact our B2B team with your target quantity, specification, delivery destination, and application requirements so we can prepare a practical supply proposal.
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