Fused Quinoline Heterocycles III: Synthesis of First Annulated 1,4,5,6,6a-Pentaazabenzo[a]indacenes, 1,3,5,6-tetraazaaceanthrylenes and 5,7,9,11-Tetraazabenzo[a]fluorenes
作者:Ramadan Ahmed Mekheimer
DOI:10.1055/s-2000-8726
日期:——
An easy and efficient synthesis of the versatile, hitherto unreported methyl 3-amino-4-chloro-1-ethyl-pyrrolo[3,2-c]quinoline-2-carboxylate (9) is described. Reaction of 9 with sodium azide gives the corresponding tetracyclic ring system 10 in near quantitative yield. With isothiocyanates 13a,b the corresponding new 1,3,5,6-tetraazaaceanthrylenes 14a and 14b are formed, respectively. Refluxing 9 with an excess of morpholine (15a) in boiling ethanol yields the corresponding pyrrolo[3,2-c]quinolines 16a which react with isothiocyanates 13a,c to afford the new 5,7,9,11-tetraazabenzo[a]fluorenes 17a,b. Refluxing 9 with an excess of butylamine affords the corresponding intermediate 16b, which reacts with ethyl chloroformate and triethyl orthoformate to furnish the novel 1,3,5,6-tetraazaaceanthrylenes 18 and 19, respectively. On the other hand, reacting 16b with acetic anhydride does not give the expected tetracyclic compound 20, but instead, the interesting pyrrolo[3,2-c]-quinolines 21 is obtained.
报道了一种简便高效的合成方法,用于制备多功能的、迄今尚未报道的甲基3-氨基-4-氯-1-乙基吡咯并[3,2-c]喹啉-2-羧酸酯(9)。将9与叠氮化钠反应,几乎定量地得到相应的四环体系10。与异硫氰酸酯13a,b反应,分别形成新的1,3,5,6-四氮杂苊并苯14a和14b。将9与过量的吗啉(15a)在沸腾乙醇中回流,得到相应的吡咯并[3,2-c]喹啉16a,它们与异硫氰酸酯13a,c反应,生成新的5,7,9,11-四氮杂苯并[a]芴17a,b。9与过量的正丁胺回流,得到相应的中间体16b,它与氯甲酸乙酯和原甲酸三乙酯反应,分别生成新的1,3,5,6-四氮杂苊并苯18和19。另一方面,将16b与乙酸酐反应,未得到预期的四环化合物20,而是得到有趣的吡咯并[3,2-c]喹啉21。