Convenient Synthesis of <i>tert</i>‐Butyl Esters of Indole‐5‐carboxylic Acid and Related Heterocyclic Carboxylic Acids
作者:Alexandra Fritsche、Heidrun Deguara、Matthias Lehr
DOI:10.1080/00397910600907290
日期:2006.10.1
Abstract The tert‐butyl esters of indole‐5‐carboxylic acid and related compounds such as benzofuran‐ and benzothiophene‐5‐carboxylic acid were readily accessed by reacting the appropriate carboxylic acids with tert‐butyl trichloroacetimidate. To obtain the tert‐butyl esters of the 5‐carboxylic acids of 1H‐benzotriazole and 1H‐benzimidazole, position 1 of these heterocycles had to be protected by acetylation
摘要 吲哚-5-羧酸的叔丁酯和相关化合物如苯并呋喃-和苯并噻吩-5-羧酸的叔丁酯很容易通过适当的羧酸与三氯乙酰亚胺叔丁酯反应得到。为了获得 1H-苯并三唑和 1H-苯并咪唑的 5-羧酸的叔丁酯,这些杂环的 1 位必须在与三氯乙酰亚胺叔丁酯反应之前通过乙酰化进行保护。用乙醇中的稀 NaOH 水溶液裂解所得中间体的乙酰基残基,得到所需的 1H-苯并三唑叔丁基酯和 1H-苯并咪唑 5-羧酸酯。