5-氨基水杨酸的合成工艺改进

Improvement of synthesis process of 5-aminosalicylic acid

摘要:

5-氨基水杨酸作为一种重要的临床药物和药物合成的中间体，可针对肠道粘膜处的炎症起到显著的抑制作用，所以对其合成工艺的研究具有重要意义。采用“一锅法”的方法对现有的5-氨基水杨酸的合成工艺进行改进。以2-氯苯甲酸为起始原料，通过n（质量分数98%硫酸）∶n（质量分数65%硝酸）= 6∶1的混酸进行硝化反应，再经使用15%氢氧化钠的亲核取代反应得到中间体5-硝基水杨酸，最后由铁粉/锌粉与浓盐酸作为还原剂进行还原反应，得到最终产物5-氨基水杨酸，总收率为61%，并且中间体及产品的结构均经IR，1HNMR和MS进行表征。

Abstract:

5-Aminosalicylic acid is either an important clinical drug or an intermediate in the synthesis of drugs, which can significantly inhibit the inflammation of the intestinal mucosa. Therefore, the research on its synthetic process is of great significance. Here it is reported that the synthetic process of 5-aminosalicylic acid is mainly improved by the “one-pot” strategy. Starting from 2-chlorobenzoic acid, the nitration reaction was carried out by the mixed acids of n (mass fraction 98% sulfuric acid): n (mass fraction of 65% nitric acid) = 6:1, and then nucleophilic substitution reaction with 15% sodium hydroxide obtained the intermediate 5-nitrosalicylic acid, and finally reduction by the reducing agent, iron powder/zinc powder and concentrated hydrochloric acid, gave the final product 5-aminosalicylic acid. The total yield of this synthetic process is 61%, and the structures of intermediate and product were characterized by IR, 1HNMR and MS.