The present invention discloses a process for the preparation of Iopamidol of formula (II) and comprising the following steps: a) reacting the Compound (I) wherein X is OR2 or R3, and wherein R2 and R3 are a Ci-C6 linear or branched alkyl, C3-C6 cycloalkyl, C6 aryl, optionally substituted with a group selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, t-butyl and phenyl, with the acylating agent (S)-2-(acetyloxy)propanoyl chloride in a reaction medium to provide the acetyloxy derivative of Compound (I); b) hydrolyzing the intermediate from step a) with an aqueous solution at a pH comprised from 0 to 7, by adding water or a diluted alkaline solution such as sodium hydroxide or potassium hydroxide, freeing the hydroxyls from the boron-containing protective groups, obtaining the N-(S)-2-(acetyloxy)propanoyl derivative of Compound (II); c) alkaline hydrolysis to restore the (S)-2-(hydroxy)propanoyl group and to obtain lopamidol (II) and optional recovery of the boron derivative from the solution obtained in step b). The boron-containing protective group is versatile, efficient and recyclable. A one-pot synthesis, without intermediate isolation is provided, leading to a decreasing of recovered and recycled solvents and a significant increasing in the yield, representing a significant advantage in terms of cost-effectiveness of the entire process and environmental awareness.
本发明公开了一种制备式Iopamidol(II)的过程,包括以下步骤:a)将化合物(I)与酰化剂(S)-2-(乙酰氧基)
丙酰氯在反应介质中反应,其中X为OR2或R3,R2和R3为C1-C6线性或支链烷基、C3-C6环烷基、C6芳基,可选地取代为甲基、乙基、正丙基、异丙基、正丁基、仲丁基、叔丁基和苯基,以提供化合物(I)的乙酰氧衍
生物;b)将步骤a)中间体与pH为0至7的
水溶液
水解,通过加入
水或稀释的碱性溶液如
氢氧化钠或
氢氧化钾,释放含
硼保护基的羟基,获得化合物(II)的N-(S)-2-(乙酰氧基)丙酰衍
生物;c)碱性
水解以恢复(S)-2-(羟基)丙酰基团并获得Iopamidol(II),并可从步骤b)中获得的溶液中可选地回收
硼衍
生物。含
硼保护基具有多功能性、高效性和可回收性。提供了一锅法合成,无需中间体分离,减少了回收和再利用的溶剂,显著提高了产率,从成本效益和环保意识方面具有显著优势。