Improved thalidomide preparation method

The invention provides a preparation method of thalidomide, which specifically comprises the following steps: (a) providing Boc-3-amino-2, 6-piperidinedione, and directly reacting the Boc-3-amino-2, 6-piperidinedione with phthalic anhydride to prepare the thalidomide. According to the method disclosed by the invention, a common synthesis route of acid salt of 3-amino-2, 6-piperidinedione and an acid-binding agent is not used, a de-protecting agent is not used for removing a Boc protecting group in advance, the process steps and the production period are remarkably shortened, the method is suitable for large-scale industrial production, and high yield and high purity are ensured while the production cost is reduced. 本发明提供了一种沙利度胺的制备方法，具体地，包括如下步骤：(a)提供Boc-3-氨基-2,6-哌啶二酮，直接与邻苯二甲酸酐反应，从而制得沙利度胺。本发明所述方法不使用常见的3-氨基-2,6-哌啶二酮的酸式盐和缚酸剂的合成路径，不使用脱保护剂预先脱Boc保护基，显著缩短了工艺步骤与生产周期，适合大规模工业化生产，并且在降低生产成本的同时保证高收率和高纯度。