3,5-Difluorophenylboronic acid stands out in chemical manufacturing and academic research. With a molecular formula of C6H5BF2O2, this compound appears as a white to off-white solid, sometimes showing up as fine powder, sometimes as crystalline flakes, depending on its purification. The CAS Number 138442-62-1 uniquely identifies it wherever chemical inventory is tracked. Its HS Code falls under 2931900090, letting customs recognize and clear it across borders as a specialty chemical. In synthetic chemistry, this material shows repeated use as a raw material for more complex molecules. Every chemist handling it knows to respect both the boronic acid group and the presence of fluorine atoms, because small changes in structure seem to shift the compound’s reactivity profile during coupling reactions or pharmaceutical production.
This compound, with its aromatic ring, two fluorine atoms in the 3 and 5 positions, and a boronic acid group attached directly to the ring, offers unique physical and chemical behavior. It usually melts between 137 and 140 degrees Celsius – a detail not lost on lab workers planning recrystallization or purification steps. The density hovers around 1.45 g/cm³, giving it a heavier feel than the unfluorinated analogs. Fluorine atoms, each known for their electronegativity, shift the electron cloud on the benzene ring and draw attention from chemists looking for more selective reactions. Structural clarity helps during nuclear magnetic resonance or mass spectrometry analysis, underlining why so many analytical chemists track exact specifications before starting a project. In my experience, a well-defined boronic acid with such clear substituents leads to fewer surprises when scaling from benchtop runs to pilot batches.
3,5-Difluorophenylboronic acid often ships as a crystalline powder or in pearl form, and customers commonly request certificates of analysis confirming purity well above 98%. Some vendors offer the material as a suspension in liquid for applications needing faster dissolution. Material safety data sheets flag it as non-volatile, and it rarely emits dust when handled right. Compared to less stable boronic acids, this compound holds its own on the shelf, resisting hydrolysis thanks to the electron-withdrawing fluorine atoms. If ordering for high-throughput synthesis or pharmaceutical utility, analysts usually check for water content, inorganic impurities, and melting range – details that matter when each synthesis step costs money and time. Many suppliers guarantee batch homogeneity because process engineers want predictable outcomes, especially where drug intermediates depend on it.
Most chemists who have worked in labs know that boronic acids can irritate the skin or eyes, but 3,5-difluorophenylboronic acid usually avoids the dramatic classifications that plague more reactive compounds. Handling requires the standard PPE: gloves, goggles, and a dust mask in poorly ventilated spaces. Breathing fine powder may cause respiratory irritation, and any accidental exposure should be washed off or flushed as standard lab procedure. Safe storage involves dry, sealed containers, away from moisture and direct sunlight. Disposal protocols usually include sending unused compound to a licensed chemical waste handler. Any spilled material should be swept up and bagged; a wet mop may hydrolyze boronic acids, making cleanup more difficult. Acute or chronic toxicity remains low, but like all boron-containing organic molecules, some special care is warranted if the process operates at scale or near food production.
Suzuki-Miyaura coupling reactions, a cornerstone for researchers building biaryl structures, have long depended on high-purity boronic acids. 3,5-Difluorophenylboronic acid often goes into agrochemical, pharmaceutical, or fine chemical synthesis because the two fluorines open doors for more diverse chemistry and drug-like properties. Large-scale users sometimes face bottlenecks in purity and price when source materials shift in quality, so companies invest in closer supply chain oversight. The push to reduce hazardous waste has led to solvent recovery systems and life-cycle studies, both of which pay off when regulations or environmental audits come around. Safe transport in solid form, proper labeling under the United Nations’ Globally Harmonized System, and full batch traceability mean a lot to quality assurance departments in multinational firms. Many of today’s innovative medicines involve fluorinated intermediates, making stewardship of this raw material vital for the future of health and technology.
