This paper describes the synthesis of two 4-amino-5H-pyrimido[5,4-b]indoles 5, 4-hydrazino-5H-pyrimido[5,4-b]indole 6, two 1,2,4-triazolo[4,3-c]pyrimido[5,4-b]indoles 8, and tetrazolo[4,5-c]pyrimido[5,4-b]indole 10. Starting with ethyl 3-aminoindole-2-carboxylate 1, 5H-pyrimido[5,4-b]indol-4-one 2 was obtained (80%) by condensing with formamide. Reactions of 2 with phosphorus oxychloride and phosphorus pentasulfide gave respectively, 4-chloro-5H-pyrimido[5,4-b]indole 3 (70%) and 5H-pyrimido[5,4-b]indole-4-thione 4 (80%). Compound 3 reacted with amines (morpholine, piperidine) to give the respective 4-amino-5H-pyrimido[5,4-b]-indoles 5, and compound 4 reacted with hydrazine to give 4-hydrazino-5H-pyrimido[5,4-b]indole 6 (80%). Two hydrazones of 6 (benzylidene, isopropylidene) 7 were also prepared (90%). Compound 6 reacted with formic and acetic acids to give (65–75%) the respective 1,2,4-triazolo[4,3-c]pyrimido[5,4-b]indoles 8 and with nitrous acid to give tetrazolo[4,5-c]pyrimido[5,4-b]indole 9 (85%). All the new compounds 2 to 9 were characterized by elemental analysis and spectral data (ir, nmr).

中文翻译：

---

4-肼基-5 H-嘧啶基[5,4- b ]吲哚的合成及相关化合物

本文描述了两种4-氨基-5-的合成ħ嘧啶并[5,4- b ]吲哚5，4-肼基-5- ħ嘧啶并[5,4- b ]吲哚6中，两个1,2,4-三唑并[4，3- c ]嘧啶[5，4- b ]吲哚8和四唑并[ 4，5- c ]嘧啶[5，4- b ]吲哚10。从3-氨基吲哚-2-羧酸乙酯1开始，通过与甲酰胺缩合获得5 H-嘧啶基[5,4 - b ]吲哚-4-酮2（80％）。2的反应用三氯氧化磷和五硫化二磷分别制得4-氯-5 H-嘧啶并[5,4- b ]吲哚3（70％）和5 H-嘧啶并[5,4- b ]吲哚并4-硫酮4（80 ％）。化合物3与胺（吗啉，哌啶）反应生成相应的4-氨基-5 H-嘧啶[5,4- b ]-吲哚5，化合物4与肼反应生成4-肼基-5 H-嘧啶[ 5,4- b ]吲哚6（80％）。两个6（亚苄基，异亚丙基）7也准备了（9​​0％）。化合物6与甲酸和乙酸反应生成（65-75％）各自的1,2,4-三唑并[4,3- c ]嘧啶基[5,4- b ]吲哚8，并与亚硝酸生成四唑并[ 4,5- c ]嘧啶基[5,4- b ]吲哚9（85％）。所有新化合物2至9均通过元素分析和光谱数据（ir，nmr）进行了表征。