中文
In traditional sulfonation reactions, reagents such as chlorosulfonic acid, fuming sulfuric acid, and liquid sulfur trioxide are highly corrosive, prone to moisture absorption, and react violently. These not only pose significant operational risks but also often lead to issues like over-sulfonation and functional group degradation—particularly in pharmaceutical intermediates and fine chemical synthesis, where “excessive sulfonation” remains a persistent challenge for research and production.
Pyridine Sulfur Trioxide Complex (CAS: 26412-87-3) is a stable complex formed between pyridine and sulfur trioxide. As a mild solid sulfonating agent, it gradually releases SO₃ reactive species in the reaction system, enabling precise control over the sulfonation process and significantly reducing side reactions. Shunxiang Pharmaceuticals leverages mature complexation technology to mass-produce high-purity pyridine sulfur trioxide complex, providing safe and controllable sulfonation solutions for the pharmaceutical and fine chemical industries.
Core Advantages
The reaction is mild and highly selective—its activity is significantly lower than that of free sulfur trioxide, enabling targeted monosulfonation while avoiding polysulfonation impurities. It exhibits excellent tolerance to functional groups such as hydroxyl, amino, and double bonds, making it suitable for complex pharmaceutical intermediates.
Solid form, safe operation — White crystalline powder, stable at room temperature and resistant to decomposition, eliminating the risks of strong volatility and corrosion associated with liquid SO₃. Easier weighing, dosing, and storage, significantly reducing workshop safety management pressure.
Broad application scenarios and excellent adaptability—Common solvents such as dichloromethane, DMF, and DMSO can all react without special equipment, allowing direct replacement of traditional sulfonating agents for production.
Typical Applications
Extensively used for the sulfation of alcohols and phenols (such as the preparation of sulfate esters from sugars, steroids, and surfactants), the sulfonation of amines to generate sulfonamides, the sulfonation of heterocyclic compounds, and the mild oxidation of primary and secondary alcohols to corresponding aldehydes and ketones in the DMSO system (an alternative to Swern oxidation), with mild conditions and no carbocation rearrangement.
Shunxiang Pharmaceutical’s sulfur trioxide pyridine has a purity of ≥98%, with strictly controlled free pyridine and SO₃ content, ensuring excellent batch stability. Produced via a sealed complexation process, each batch is accompanied by a COA test report. We maintain regular inventory to support small trial samples and stable bulk supply, and welcome inquiries for trial samples from pharmaceutical R&D, CRO, and fine chemical companies.