3,4-Difluorophenylboronic Acid stands out as a valuable raw material in modern laboratories, especially in pharmaceutical and specialty chemical synthesis. This compound features a molecular formula of C6H5BF2O2, and sits as a critical tool for Suzuki-Miyaura cross-coupling reactions. The addition of two fluorine atoms at the 3 and 4 positions on the phenyl ring has a direct impact on its reactivity, stability, and chemical behavior. Many experienced chemists lean on such derivatives to access novel fluorinated drugs or advanced organic materials. The CAS number associated with this compound is 174922-66-2, a reference point for tracking regulatory compliance and grade verification.
In my own bench work, I have found 3,4-Difluorophenylboronic Acid typically presents as a white to off-white solid in various forms, such as flakes, powder, or even crystalline pearls, depending on the batch purity and storage conditions. Powdered samples allow for faster solubilization, which speeds up reaction setups. The density lies around 1.43 g/cm3, appreciably heavier than many simple boronic acids. Melting point tends to gather around 140-144°C, ensuring enough stability during storage but not so high as to require overly aggressive lab ware or extended heating when dissolving. As a solid, it stores easily in dry, sealed containers, away from sources of moisture—exposure to water can degrade its boronic acid group, releasing boric acid and free phenols.
The molecule has a planar phenyl ring with fluorine atoms replacing hydrogen at the 3 and 4 positions, giving it new electronic features compared to the unsubstituted parent acid. The boronic acid group attaches directly to the ring, making it suitable for reactions with aryl halides and vinyl partners under palladium catalysis. Even without advanced training, you notice that boronic acids are not just specialty reagents—they open doors to biaryl structures seen in modern drug targets, electronics, and new materials. The electron-withdrawing effects of the two fluorine atoms tilt the acidity upward slightly, impacting reaction rates and selectivity. Its structural reliability lets process chemists dial in key attributes, like yield and regioselectivity, in pilot and commercial scale projects.
Suppliers offer 3,4-Difluorophenylboronic Acid at purity levels above 97%, with some HPLC-verified batches exceeding 99%. The solid may come as fine white powder, or occasionally as coarse crystalline flakes. Moisture content stays below 0.5%, preventing unwanted hydrolysis before use. The acid dissolves in organic solvents such as DMSO, THF, or ethanol, while remaining only sparingly soluble in water. Batches get packed in airtight bottles, often amber glass, to block out light and humidity. Laboratory staff weigh out the material directly; accuracy in dosing is vital since many reactions rely on precise mol ratios, especially in transition metal catalysis. No special refrigeration is needed for short-term storage, but prolonged warehouse stays call for cool, dry conditions to discourage slow hydrolysis or oxidation.
International shipping and customs clearance follow the Harmonized System, where 3,4-Difluorophenylboronic Acid falls under HS code 2931.39. This code covers organic compounds like boronic acids, aligning with broader tracking for inventory and environmental documentation. In regulated regions or for certain pharmaceutical R&D, documentation accompanies each shipment to certify compliance and quality assurance. Documentation also lays out batch traceability, impurity levels, and safety data to support workplace training, emergency response, and downstream waste handling.
Despite the practical uses, users take care when handling. Dust formed during weighing or transfer can irritate the respiratory system, and direct skin or eye contact should be avoided. 3,4-Difluorophenylboronic Acid does not count as acutely toxic by inhalation or contact, but labs label it as harmful based on its chemical nature and lack of comprehensive toxicological data. Spill kits with absorbent material make cleanup easier, limiting risk. Any unused product or contaminated gloves and paper head to chemical waste buckets marked for phenylboronic acids. Proper gloves and splash goggles deliver essential protection; lab coats prevent skin staining that can last thanks to the affinity of phenyl species for cellulose fibers.
In the search for improved pharmaceuticals and advanced materials, 3,4-Difluorophenylboronic Acid earns its reputation as a trusted starting point. The ability to tune aromatic rings with fluorine changes more than just reactivity—these modifications can give rise to higher metabolic stability, better target selectivity, and even novel bioactivity profiles. I have worked with this material in both manual flask setups and automated reactors, and it stays remarkably pure, with minimal byproducts during coupling reactions. This lets downstream purification move faster, saving hours on flash columns or preparative HPLC. It feels satisfying to run a reaction, check by TLC, and spot a single band, hinting at just how much careful design goes into making specialty boronic acids. They may look simple but underpin a wide array of molecular innovations.
Bulk shipments get packed in heavy-duty containers lined with dry bags to safeguard from moisture, while lab-scale amounts come in glass vials or plastic jars under nitrogen. In my own practice, solubilizing 3,4-Difluorophenylboronic Acid for solution-phase work involves slow addition into stirred solvent, allowing for complete wetting and dispersion before heating. Crystalline grains break apart quickly, while finer powders disperse into even, cloudless solutions. It helps to weigh in a humidity-controlled space to maintain integrity between opening and resealing the jar. As with many organoboron materials, I have found that storing in a desiccator prolongs shelf life—a tip passed down from veteran chemists who saw too many hoarded bottles succumb to clumping after a summer on the shelf.
Dealing with reactive raw materials calls for a mix of technical understanding and practical risk reduction. Color changes, clumping, or strong odors indicate impurity growth or hydrolysis, so regular inspection and batch turnover make a difference in quality control. Small-scale pre-runs in new synthetic routes smooth out problems before investing larger amounts. Using pre-packed desiccants in supply containers buys weeks or months of stable shelf life. Transparent safety protocols, such as regular training in handling powders and managing spills, safeguard the workspace from minor accidents that can disrupt vital research. Beyond the technical side, open dialogue between buyers, handlers, and users keeps feedback flowing, updating best practices across chemical development, supply, and end-use.
