Synthesis of pyrrolo[2,1-f][1,2,4]triazine C-nucleosides. Isosteres of sangivamycin, tubercidin, and toyocamycin
作者:Natsu Nishimura、Ai Kato、Isamu Maeba
DOI:10.1016/s0008-6215(01)00017-9
日期:2001.3
5-formylpyrrolo[2,1-f][1,2,4]triazine, in 69% yield. The aldehyde was treated with hydroxylamine hydrochloride in methanol to give aldoximes. Dehydration of aldoxime with trifluoromethanesulfonic anhydride and triethylamine in dichloromethane afforded 5-cyanopyrrolo[2,1-f][1,2,4]triazine in 44% yield. Conversion of the nitrile to the deprotected amide, 2-amino-7-(beta-D-ribofuranosyl)pyrrolo[2,1-f][1,2,4]triazine-5-carboxamide
报道了吡咯并[2,1-f] [1,2,4]三嗪C-核苷的合成。用氨基胍在乙酸中处理吡喃糖苷,以96%的收率得到相应的半卡巴zone。半卡巴zone在二恶烷中的环转化提供了51%的2-氨基-7-(2,3,5-三-O-苯甲酰基-β-D-呋喃呋喃糖基)吡咯并[2,1-f]-[1]收率,2,4]三嗪。吡咯并三嗪的维尔斯迈尔甲酰化反应以69%的收率得到了主要产物5-甲酰基吡咯并[2,1-f] [1,2,4]三嗪。用甲醇中的盐酸羟胺处理醛,得到醛肟。用三氟甲磺酸酐和三乙胺在二氯甲烷中使醛肟肟脱水,得到5-氰基吡咯并[2,1-f] [1,2,4]三嗪,产率为44%。腈转化为脱保护的酰胺2-氨基-7-(β-D-呋喃呋喃糖基)吡咯并[2,1-f] [1,2,4]三嗪-5-甲酰胺,在室温下用30%H2O2的乙醇溶液处理1天,可实现96%的收率。用氢氧化钠溶液脱苯甲酰化产生脱保护的C-核苷。