中文
Pyridine hydrobromide (Chemical formula: C₅H₆BrN) is a white or off-white crystalline solid with the properties of a strong acid-weak base salt. It has a melting point of approximately 200°C (some data indicate 217–220°C) and a boiling point of 115.3°C (760 mmHg). Its low flash point indicates relative stability at room temperature but requires avoidance of high-temperature environments. The compound is soluble in water and ethanol but insoluble in nonpolar solvents such as acetone, carbon tetrachloride, and aromatic hydrocarbons, giving it unique advantages in chemical separation and purification processes. Additionally, its strong hygroscopicity necessitates sealed storage in a cool, dry place to maintain chemical stability.
In the chemical industry, the core value of pyridinium bromide stems from its multifunctionality. As a pharmaceutical intermediate, it is widely used in the synthesis of cephalosporin antibiotics (such as cefathiamidine and ceftazidime) and serves as a key component in the production of 7-ADCA (7-amino-4-carboxy-cephalosporanic acid), where optimizing its molecular structure enhances drug activity and bioavailability. It excels in organic synthesis, acting as an efficient catalyst in alkylation, acylation, and esterification reactions, significantly reducing reaction temperatures and energy consumption while improving product purity and yield. For instance, in the synthesis of diphenylacetylene, it facilitates trans-addition reactions, ensuring precise product structure. Additionally, this compound is utilized in papermaking auxiliaries and the preparation of high-performance polymer materials, enhancing mechanical strength and weather resistance to provide innovative solutions for electronic components and coatings.
The physicochemical properties of hydrobromide further support its industrial applications. Its strong acidity (pH approximately 2.65–2.75) effectively facilitates proton transfer during catalytic processes, accelerating reaction progress. In terms of stability, this salt demonstrates reliable performance in inert atmospheres but requires caution due to its skin corrosion hazard classification (Category 1B). Protective equipment must be worn during handling to mitigate contact risks. Overall, hydrobromide has become an indispensable reagent in chemical synthesis, offering sustained technical driving force for pharmaceuticals, materials, and fine chemical industries, owing to its efficiency, stability, and cross-domain adaptability.