Using 5% aq. NaOH, a simple method for the transformation of 3-cyanoacetylindoles 2(a-e) into 3- acetylindoles 3 (a-e), in good yields, is reported. Tetrabutylammoniumbromide (TBAB) is found to be an efficient phase transfer catalyst for the synthesis of N-alkyl derivatives 5(a-t) of 3-acetylindoles 3(a-e) giving products in excellent yields. 2 (a-e) were themselves obtained from simple indoles 1 (a-e) by reaction with cyano acetic acid in the presence of propionic anhydride at 100 °C for 5-10 min. Partial hydrolysis of 2 (a-e) under hot acidic conditions yielded the corresponding carboxamides α-(3-indolecarboxoyl)acetamides 4(a-e). Which could be readily transformed into the respective 3(a-e) by refluxing with 5% aq. NaOH for 2-2.5 h.
报道了一种利用5%
氢氧化钠水溶液,将3-
氰基乙酰基
吲哚2(a-e)高效转化为3-乙酰基
吲哚3(a-e)的简便方法。
四丁基溴化铵(TBAB)被发现是一种有效的相转移催化剂,用于合成3-乙酰基
吲哚3(a-e)的N-烷基衍
生物5(a-t),产率优异。2(a-e)本身是通过
吲哚1(a-e)与
氰基
乙酸在
丙酸酐存在下于100°C反应5-10分钟得到的。在热酸性条件下部分
水解2(a-e),得到相应的羧酰胺α-(3-
吲哚羧酰基)乙酰胺4(a-e),这些羧酰胺可以通过与5%
氢氧化钠水溶液回流2-2.5小时,容易地转化为相应的3(a-e)。