苄胺的磺化及其合成工艺优化

Sulfonation of Benzylamine and Optimization of Its Synthesis Process

摘要: 苄胺的磺化反应是合成4-(氨基甲基)苯-1-磺酸的关键路径，该产物作为一类典型的双官能团中间体，因同时具备反应活性强的氨基与亲水性能优异的磺酸基，在医药、染料、表面活性剂及水处理等多个领域具有不可替代的应用价值。磺化是合成氨基磺酸化合物重要的化学工艺，目前主要的合成方法是利用磺化剂将芳基氨直接磺化，常用的磺化试剂主要有发烟硫酸、氯磺酸、硫酸、三氟乙酸–硫酸、格式锂试剂进行格氏磺化、用亚硫酸钠进行亲核芳香族取代、用三氧化硫–二氧六环络合物磺化、使用二氧化硅负载的硫酸以及通过超声波辐射辅助硫酸磺化等方法。本文系统阐述了用氯磺酸直接磺化法磺化苄胺合成4-(氨基甲基)苯-1-磺酸，从反应溶剂、淬灭试剂、投料比例等方面进行全面对比分析。针对苄胺磺化反应中存在的选择性不足、试剂腐蚀性强、环保压力大等问题，深入探讨了工艺优化策略，通过调控反应温度、原料摩尔比、溶剂体系、加料方式等关键参数，可有效提升对位磺化选择性，研究表明，氯磺酸直接磺化法经工艺优化后，产物收率可达83%，适合工业化大规模生产；制备出HPLC纯度>99%的产物，满足医药级中间体的高纯度需求。

Abstract: As a typical bifunctional group intermediate, this product has irreplaceable application value in many fields such as medicine, dyes, surfactants and water treatment because it has both strong reactive amino groups and sulfonic acid groups with excellent hydrophilic properties. Sulfonation is an important chemical process for the synthesis of sulfamic acid compounds, and the main synthesis method is to use sulfonating agents to directly sulfonate aryl ammonia, and the commonly used sulfonation reagents are mainly fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, trifluoroacetic acid-sulfuric acid, format lithium reagent for Grigeli sulfonation, sodium sulfite for nucleophilic aromatic substitution, sulfur trioxide-dioxane complex sulfonation, silica-loaded sulfuric acid, and ultrasonic radiation assisted sulfuric acid sulfonation and other methods. In this paper, the synthesis of 4-(aminomethyl)benzene sulfonic acid by chlorosulfonic acid direct sulfonation method is systematically described, and a comprehensive comparative analysis is carried out from the aspects of reaction solvent, quenching reagent and feeding ratio. In view of the problems of insufficient selectivity, strong corrosiveness of reagents, and high environmental pressure in the benzylamine sulfonation reaction, the process optimization strategy was deeply discussed, and the selectivity of parasulfonation could be effectively improved by regulating key parameters such as reaction temperature, raw material molar ratio, solvent system, and feeding method. HPLC products with a purity > 99% were prepared to meet the high purity requirements of pharmaceutical-grade intermediates.